Gitiles
Code Review Sign In
gerrit-public.fairphone.software / toolchain / llvm-project / 964cb5feb0885460c50ac4c0962d108cb193ba1e / . / llvm / docs / LangRef.html
blob: bc72144ff71f907f2089d316a956ca315a547f50 [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>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]58 <li><a href="#typesystem">Type System</a>
59 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]60 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]61 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]62 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]63 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]64 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]65 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_void">Void Type</a></li>
67 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]68 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]69 </ol>
70 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]71 <li><a href="#t_derived">Derived Types</a>
72 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]73 <li><a href="#t_aggregate">Aggregate Types</a>
74 <ol>
75 <li><a href="#t_array">Array Type</a></li>
76 <li><a href="#t_struct">Structure Type</a></li>
77 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]78 <li><a href="#t_vector">Vector Type</a></li>
79 </ol>
80 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#t_function">Function Type</a></li>
82 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]83 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]86 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]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>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]127 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]128 </ol>
129 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]130 <li><a href="#binaryops">Binary Operations</a>
131 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]136 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]137 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]138 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
139 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
140 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]141 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
142 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
143 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]144 </ol>
145 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]146 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
147 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]148 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
149 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
150 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]152 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]153 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]154 </ol>
155 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]156 <li><a href="#vectorops">Vector Operations</a>
157 <ol>
158 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
159 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
160 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]161 </ol>
162 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]163 <li><a href="#aggregateops">Aggregate Operations</a>
164 <ol>
165 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
166 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
167 </ol>
168 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]169 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]170 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]171 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]172 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
173 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
174 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]175 </ol>
176 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]177 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]178 <ol>
179 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
180 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
181 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]184 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
185 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
186 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
187 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]188 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
189 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]190 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]191 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]192 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]193 <li><a href="#otherops">Other Operations</a>
194 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]195 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
196 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]198 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]199 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]200 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]201 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]202 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]203 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]204 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]205 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]206 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]207 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
208 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]209 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
210 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
211 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]214 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
215 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]216 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
217 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
218 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]219 </ol>
220 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]221 <li><a href="#int_codegen">Code Generator Intrinsics</a>
222 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]223 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
224 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
225 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
226 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
227 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
228 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]229 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]230 </ol>
231 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]232 <li><a href="#int_libc">Standard C Library Intrinsics</a>
233 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]234 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]239 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]242 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
243 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]244 </ol>
245 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]246 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]247 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]248 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]249 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
250 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
251 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]252 </ol>
253 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]254 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
255 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]256 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
257 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
260 <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]261 <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]262 </ol>
263 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]264 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
265 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]266 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
267 <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]268 </ol>
269 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]270 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]271 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]272 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]273 <ol>
274 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]275 </ol>
276 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]277 <li><a href="#int_atomics">Atomic intrinsics</a>
278 <ol>
279 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
280 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
281 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
282 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
283 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
284 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
285 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
286 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
287 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
288 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
289 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
290 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
291 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
292 </ol>
293 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]294 <li><a href="#int_memorymarkers">Memory Use Markers</a>
295 <ol>
296 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
297 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
298 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
299 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
300 </ol>
301 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]302 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]303 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]304 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]306 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]307 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]308 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.trap</tt>' Intrinsic</a></li>
310 <li><a href="#int_stackprotector">
311 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]312 <li><a href="#int_objectsize">
313 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]314 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]315 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]316 </ol>
317 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]318</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]319
320<div class="doc_author">
321 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
322 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]323</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]325<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]326<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]328
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]329<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]330
331<p>This document is a reference manual for the LLVM assembly language. LLVM is
332 a Static Single Assignment (SSA) based representation that provides type
333 safety, low-level operations, flexibility, and the capability of representing
334 'all' high-level languages cleanly. It is the common code representation
335 used throughout all phases of the LLVM compilation strategy.</p>
336
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]337</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]338
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]339<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]340<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]341<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]342
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]343<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]344
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]345<p>The LLVM code representation is designed to be used in three different forms:
346 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
347 for fast loading by a Just-In-Time compiler), and as a human readable
348 assembly language representation. This allows LLVM to provide a powerful
349 intermediate representation for efficient compiler transformations and
350 analysis, while providing a natural means to debug and visualize the
351 transformations. The three different forms of LLVM are all equivalent. This
352 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]354<p>The LLVM representation aims to be light-weight and low-level while being
355 expressive, typed, and extensible at the same time. It aims to be a
356 "universal IR" of sorts, by being at a low enough level that high-level ideas
357 may be cleanly mapped to it (similar to how microprocessors are "universal
358 IR's", allowing many source languages to be mapped to them). By providing
359 type information, LLVM can be used as the target of optimizations: for
360 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]361 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]362 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]364<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]365<h4>
366 <a name="wellformed">Well-Formedness</a>
367</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]368
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]369<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]371<p>It is important to note that this document describes 'well formed' LLVM
372 assembly language. There is a difference between what the parser accepts and
373 what is considered 'well formed'. For example, the following instruction is
374 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]376<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]377%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]378</pre>
379
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]380<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
381 LLVM infrastructure provides a verification pass that may be used to verify
382 that an LLVM module is well formed. This pass is automatically run by the
383 parser after parsing input assembly and by the optimizer before it outputs
384 bitcode. The violations pointed out by the verifier pass indicate bugs in
385 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]386
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]387</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]388
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]389</div>
390
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]391<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]392
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]393<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]394<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]395<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]396
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]397<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]398
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]399<p>LLVM identifiers come in two basic types: global and local. Global
400 identifiers (functions, global variables) begin with the <tt>'@'</tt>
401 character. Local identifiers (register names, types) begin with
402 the <tt>'%'</tt> character. Additionally, there are three different formats
403 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]404
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]405<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]406 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]407 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
408 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
409 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
410 other characters in their names can be surrounded with quotes. Special
411 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
412 ASCII code for the character in hexadecimal. In this way, any character
413 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]414
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]415 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]416 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]417
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]418 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]419 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]420</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]422<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]423 don't need to worry about name clashes with reserved words, and the set of
424 reserved words may be expanded in the future without penalty. Additionally,
425 unnamed identifiers allow a compiler to quickly come up with a temporary
426 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]427
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]428<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]429 languages. There are keywords for different opcodes
430 ('<tt><a href="#i_add">add</a></tt>',
431 '<tt><a href="#i_bitcast">bitcast</a></tt>',
432 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
433 ('<tt><a href="#t_void">void</a></tt>',
434 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
435 reserved words cannot conflict with variable names, because none of them
436 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]437
438<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]439 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]440
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]441<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]443<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]444%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]445</pre>
446
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]447<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]449<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]450%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]451</pre>
452
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]453<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]454
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]455<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]456%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
457%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]458%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459</pre>
460
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]461<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
462 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]463
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]464<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]466 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
468 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]469 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]470
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]471 <li>Unnamed temporaries are numbered sequentially</li>
472</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]473
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]474<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]475 demonstrating instructions, we will follow an instruction with a comment that
476 defines the type and name of value produced. Comments are shown in italic
477 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]478
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]479</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]480
481<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]482<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]483<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]484<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]485<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]486<h3>
487 <a name="modulestructure">Module Structure</a>
488</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]490<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]492<p>LLVM programs are composed of "Module"s, each of which is a translation unit
493 of the input programs. Each module consists of functions, global variables,
494 and symbol table entries. Modules may be combined together with the LLVM
495 linker, which merges function (and global variable) definitions, resolves
496 forward declarations, and merges symbol table entries. Here is an example of
497 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]498
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]499<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]500<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]501<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]502
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]503<i>; External declaration of the puts function</i>&nbsp;
504<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]505
506<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]507define i32 @main() { <i>; i32()* </i>&nbsp;
508 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
509 %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]510
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]511 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
512 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
513 <a href="#i_ret">ret</a> i32 0&nbsp;
514}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]515
516<i>; Named metadata</i>
517!1 = metadata !{i32 41}
518!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]519</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]521<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]522 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]524 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
525 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]527<p>In general, a module is made up of a list of global values, where both
528 functions and global variables are global values. Global values are
529 represented by a pointer to a memory location (in this case, a pointer to an
530 array of char, and a pointer to a function), and have one of the
531 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]532
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]533</div>
534
535<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]536<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]537 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]538</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]539
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]540<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]541
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]542<p>All Global Variables and Functions have one of the following types of
543 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]544
545<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]547 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
548 by objects in the current module. In particular, linking code into a
549 module with an private global value may cause the private to be renamed as
550 necessary to avoid collisions. Because the symbol is private to the
551 module, all references can be updated. This doesn't show up in any symbol
552 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]553
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]555 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
556 assembler and evaluated by the linker. Unlike normal strong symbols, they
557 are removed by the linker from the final linked image (executable or
558 dynamic library).</dd>
559
560 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
561 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
562 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
563 linker. The symbols are removed by the linker from the final linked image
564 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]565
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]566 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
567 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
568 of the object is not taken. For instance, functions that had an inline
569 definition, but the compiler decided not to inline it. Note,
570 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
571 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
572 visibility. The symbols are removed by the linker from the final linked
573 image (executable or dynamic library).</dd>
574
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]575 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]576 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]577 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
578 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]579
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]581 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]582 into the object file corresponding to the LLVM module. They exist to
583 allow inlining and other optimizations to take place given knowledge of
584 the definition of the global, which is known to be somewhere outside the
585 module. Globals with <tt>available_externally</tt> linkage are allowed to
586 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
587 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]588
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]589 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]590 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]591 the same name when linkage occurs. This can be used to implement
592 some forms of inline functions, templates, or other code which must be
593 generated in each translation unit that uses it, but where the body may
594 be overridden with a more definitive definition later. Unreferenced
595 <tt>linkonce</tt> globals are allowed to be discarded. Note that
596 <tt>linkonce</tt> linkage does not actually allow the optimizer to
597 inline the body of this function into callers because it doesn't know if
598 this definition of the function is the definitive definition within the
599 program or whether it will be overridden by a stronger definition.
600 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
601 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]602
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]603 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]604 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
605 <tt>linkonce</tt> linkage, except that unreferenced globals with
606 <tt>weak</tt> linkage may not be discarded. This is used for globals that
607 are declared "weak" in C source code.</dd>
608
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]610 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
611 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
612 global scope.
613 Symbols with "<tt>common</tt>" linkage are merged in the same way as
614 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]615 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]616 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]617 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
618 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]619
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]620
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]621 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]622 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]623 pointer to array type. When two global variables with appending linkage
624 are linked together, the two global arrays are appended together. This is
625 the LLVM, typesafe, equivalent of having the system linker append together
626 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]627
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]628 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]629 <dd>The semantics of this linkage follow the ELF object file model: the symbol
630 is weak until linked, if not linked, the symbol becomes null instead of
631 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]632
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]633 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
634 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]635 <dd>Some languages allow differing globals to be merged, such as two functions
636 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]637 that only equivalent globals are ever merged (the "one definition rule"
638 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]639 and <tt>weak_odr</tt> linkage types to indicate that the global will only
640 be merged with equivalent globals. These linkage types are otherwise the
641 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]642
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]643 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]644 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]645 visible, meaning that it participates in linkage and can be used to
646 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]647</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]648
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]649<p>The next two types of linkage are targeted for Microsoft Windows platform
650 only. They are designed to support importing (exporting) symbols from (to)
651 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]653<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]654 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]655 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]656 or variable via a global pointer to a pointer that is set up by the DLL
657 exporting the symbol. On Microsoft Windows targets, the pointer name is
658 formed by combining <code>__imp_</code> and the function or variable
659 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]660
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]661 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]662 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]663 pointer to a pointer in a DLL, so that it can be referenced with the
664 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
665 name is formed by combining <code>__imp_</code> and the function or
666 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]667</dl>
668
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]669<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
670 another module defined a "<tt>.LC0</tt>" variable and was linked with this
671 one, one of the two would be renamed, preventing a collision. Since
672 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
673 declarations), they are accessible outside of the current module.</p>
674
675<p>It is illegal for a function <i>declaration</i> to have any linkage type
676 other than "externally visible", <tt>dllimport</tt>
677 or <tt>extern_weak</tt>.</p>
678
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]679<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]680 or <tt>weak_odr</tt> linkages.</p>
681
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]682</div>
683
684<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]685<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]686 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]687</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]688
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]689<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]690
691<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]692 and <a href="#i_invoke">invokes</a> can all have an optional calling
693 convention specified for the call. The calling convention of any pair of
694 dynamic caller/callee must match, or the behavior of the program is
695 undefined. The following calling conventions are supported by LLVM, and more
696 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]697
698<dl>
699 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]700 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]701 specified) matches the target C calling conventions. This calling
702 convention supports varargs function calls and tolerates some mismatch in
703 the declared prototype and implemented declaration of the function (as
704 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]705
706 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]708 (e.g. by passing things in registers). This calling convention allows the
709 target to use whatever tricks it wants to produce fast code for the
710 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]711 (Application Binary Interface).
712 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]713 when this or the GHC convention is used.</a> This calling convention
714 does not support varargs and requires the prototype of all callees to
715 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]716
717 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]718 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]719 as possible under the assumption that the call is not commonly executed.
720 As such, these calls often preserve all registers so that the call does
721 not break any live ranges in the caller side. This calling convention
722 does not support varargs and requires the prototype of all callees to
723 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]724
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]725 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
726 <dd>This calling convention has been implemented specifically for use by the
727 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
728 It passes everything in registers, going to extremes to achieve this by
729 disabling callee save registers. This calling convention should not be
730 used lightly but only for specific situations such as an alternative to
731 the <em>register pinning</em> performance technique often used when
732 implementing functional programming languages.At the moment only X86
733 supports this convention and it has the following limitations:
734 <ul>
735 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
736 floating point types are supported.</li>
737 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
738 6 floating point parameters.</li>
739 </ul>
740 This calling convention supports
741 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
742 requires both the caller and callee are using it.
743 </dd>
744
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]745 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]746 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]747 target-specific calling conventions to be used. Target specific calling
748 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]749</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]750
751<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]752 support Pascal conventions or any other well-known target-independent
753 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]754
755</div>
756
757<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]758<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]759 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]760</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]761
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]762<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]764<p>All Global Variables and Functions have one of the following visibility
765 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]766
767<dl>
768 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]769 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]770 that the declaration is visible to other modules and, in shared libraries,
771 means that the declared entity may be overridden. On Darwin, default
772 visibility means that the declaration is visible to other modules. Default
773 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]774
775 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]776 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]777 object if they are in the same shared object. Usually, hidden visibility
778 indicates that the symbol will not be placed into the dynamic symbol
779 table, so no other module (executable or shared library) can reference it
780 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]781
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]782 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]783 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]784 the dynamic symbol table, but that references within the defining module
785 will bind to the local symbol. That is, the symbol cannot be overridden by
786 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]787</dl>
788
789</div>
790
791<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]792<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]793 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]794</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]795
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]796<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]797
798<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]799 it easier to read the IR and make the IR more condensed (particularly when
800 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]801
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]802<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]803%mytype = type { %mytype*, i32 }
804</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]805
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]806<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]807 "<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]808 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]809
810<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]811 and that you can therefore specify multiple names for the same type. This
812 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
813 uses structural typing, the name is not part of the type. When printing out
814 LLVM IR, the printer will pick <em>one name</em> to render all types of a
815 particular shape. This means that if you have code where two different
816 source types end up having the same LLVM type, that the dumper will sometimes
817 print the "wrong" or unexpected type. This is an important design point and
818 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]819
820</div>
821
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]822<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]823<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]824 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]825</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]826
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]827<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]828
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]829<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]830 instead of run-time. Global variables may optionally be initialized, may
831 have an explicit section to be placed in, and may have an optional explicit
832 alignment specified. A variable may be defined as "thread_local", which
833 means that it will not be shared by threads (each thread will have a
834 separated copy of the variable). A variable may be defined as a global
835 "constant," which indicates that the contents of the variable
836 will <b>never</b> be modified (enabling better optimization, allowing the
837 global data to be placed in the read-only section of an executable, etc).
838 Note that variables that need runtime initialization cannot be marked
839 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]840
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]841<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
842 constant, even if the final definition of the global is not. This capability
843 can be used to enable slightly better optimization of the program, but
844 requires the language definition to guarantee that optimizations based on the
845 'constantness' are valid for the translation units that do not include the
846 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]847
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]848<p>As SSA values, global variables define pointer values that are in scope
849 (i.e. they dominate) all basic blocks in the program. Global variables
850 always define a pointer to their "content" type because they describe a
851 region of memory, and all memory objects in LLVM are accessed through
852 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]853
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]854<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
855 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]856 like this can be merged with other constants if they have the same
857 initializer. Note that a constant with significant address <em>can</em>
858 be merged with a <tt>unnamed_addr</tt> constant, the result being a
859 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]860
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]861<p>A global variable may be declared to reside in a target-specific numbered
862 address space. For targets that support them, address spaces may affect how
863 optimizations are performed and/or what target instructions are used to
864 access the variable. The default address space is zero. The address space
865 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]866
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]867<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]868 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]869
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]870<p>An explicit alignment may be specified for a global, which must be a power
871 of 2. If not present, or if the alignment is set to zero, the alignment of
872 the global is set by the target to whatever it feels convenient. If an
873 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]874 alignment. Targets and optimizers are not allowed to over-align the global
875 if the global has an assigned section. In this case, the extra alignment
876 could be observable: for example, code could assume that the globals are
877 densely packed in their section and try to iterate over them as an array,
878 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]879
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]880<p>For example, the following defines a global in a numbered address space with
881 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]882
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]883<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]884@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]885</pre>
886
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]887</div>
888
889
890<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]891<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]892 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]893</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]894
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]895<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]896
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]897<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]898 optional <a href="#linkage">linkage type</a>, an optional
899 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]900 <a href="#callingconv">calling convention</a>,
901 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]902 <a href="#paramattrs">parameter attribute</a> for the return type, a function
903 name, a (possibly empty) argument list (each with optional
904 <a href="#paramattrs">parameter attributes</a>), optional
905 <a href="#fnattrs">function attributes</a>, an optional section, an optional
906 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
907 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]908
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]909<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
910 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]911 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]912 <a href="#callingconv">calling convention</a>,
913 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]914 <a href="#paramattrs">parameter attribute</a> for the return type, a function
915 name, a possibly empty list of arguments, an optional alignment, and an
916 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]917
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]918<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]919 (Control Flow Graph) for the function. Each basic block may optionally start
920 with a label (giving the basic block a symbol table entry), contains a list
921 of instructions, and ends with a <a href="#terminators">terminator</a>
922 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]923
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]924<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]925 executed on entrance to the function, and it is not allowed to have
926 predecessor basic blocks (i.e. there can not be any branches to the entry
927 block of a function). Because the block can have no predecessors, it also
928 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]929
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]930<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]931 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]932
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]933<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]934 the alignment is set to zero, the alignment of the function is set by the
935 target to whatever it feels convenient. If an explicit alignment is
936 specified, the function is forced to have at least that much alignment. All
937 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]938
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]939<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
940 be significant and two identical functions can be merged</p>.
941
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]942<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]943<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]944define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]945 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
946 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
947 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
948 [<a href="#gc">gc</a>] { ... }
949</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]950
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]951</div>
952
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]953<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]954<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]955 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]956</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]957
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]958<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]959
960<p>Aliases act as "second name" for the aliasee value (which can be either
961 function, global variable, another alias or bitcast of global value). Aliases
962 may have an optional <a href="#linkage">linkage type</a>, and an
963 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]964
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]965<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]966<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]967@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]968</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]969
970</div>
971
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]972<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]973<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]974 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]975</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]976
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]977<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]978
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]979<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]980 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]981 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]982
983<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]984<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]985; Some unnamed metadata nodes, which are referenced by the named metadata.
986!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]987!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]988!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]989; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]990!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]991</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]992
993</div>
994
995<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]996<h3>
997 <a name="paramattrs">Parameter Attributes</a>
998</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]999
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1000<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1001
1002<p>The return type and each parameter of a function type may have a set of
1003 <i>parameter attributes</i> associated with them. Parameter attributes are
1004 used to communicate additional information about the result or parameters of
1005 a function. Parameter attributes are considered to be part of the function,
1006 not of the function type, so functions with different parameter attributes
1007 can have the same function type.</p>
1008
1009<p>Parameter attributes are simple keywords that follow the type specified. If
1010 multiple parameter attributes are needed, they are space separated. For
1011 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1012
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1013<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1014declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1015declare i32 @atoi(i8 zeroext)
1016declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1017</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1018
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1019<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1020 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1021
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1022<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1023
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1024<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1025 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1026 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1027 should be zero-extended to the extent required by the target's ABI (which
1028 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1029 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1030
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1033 should be sign-extended to the extent required by the target's ABI (which
1034 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1035 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1036
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1037 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This indicates that this parameter or return value should be treated in a
1039 special target-dependent fashion during while emitting code for a function
1040 call or return (usually, by putting it in a register as opposed to memory,
1041 though some targets use it to distinguish between two different kinds of
1042 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1043
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1044 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1045 <dd><p>This indicates that the pointer parameter should really be passed by
1046 value to the function. The attribute implies that a hidden copy of the
1047 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1048 is made between the caller and the callee, so the callee is unable to
1049 modify the value in the callee. This attribute is only valid on LLVM
1050 pointer arguments. It is generally used to pass structs and arrays by
1051 value, but is also valid on pointers to scalars. The copy is considered
1052 to belong to the caller not the callee (for example,
1053 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1054 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1055 values.</p>
1056
1057 <p>The byval attribute also supports specifying an alignment with
1058 the align attribute. It indicates the alignment of the stack slot to
1059 form and the known alignment of the pointer specified to the call site. If
1060 the alignment is not specified, then the code generator makes a
1061 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1062
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1063 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1064 <dd>This indicates that the pointer parameter specifies the address of a
1065 structure that is the return value of the function in the source program.
1066 This pointer must be guaranteed by the caller to be valid: loads and
1067 stores to the structure may be assumed by the callee to not to trap. This
1068 may only be applied to the first parameter. This is not a valid attribute
1069 for return values. </dd>
1070
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1071 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1072 <dd>This indicates that pointer values
1073 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1074 value do not alias pointer values which are not <i>based</i> on it,
1075 ignoring certain "irrelevant" dependencies.
1076 For a call to the parent function, dependencies between memory
1077 references from before or after the call and from those during the call
1078 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1079 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1080 The caller shares the responsibility with the callee for ensuring that
1081 these requirements are met.
1082 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1083 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1084<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1085 Note that this definition of <tt>noalias</tt> is intentionally
1086 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1087 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1088<br>
1089 For function return values, C99's <tt>restrict</tt> is not meaningful,
1090 while LLVM's <tt>noalias</tt> is.
1091 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1092
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1093 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1094 <dd>This indicates that the callee does not make any copies of the pointer
1095 that outlive the callee itself. This is not a valid attribute for return
1096 values.</dd>
1097
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1098 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This indicates that the pointer parameter can be excised using the
1100 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1101 attribute for return values.</dd>
1102</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1103
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1104</div>
1105
1106<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1107<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1108 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1109</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1110
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1111<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1112
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1113<p>Each function may specify a garbage collector name, which is simply a
1114 string:</p>
1115
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1116<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1117define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1118</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1119
1120<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1121 collector which will cause the compiler to alter its output in order to
1122 support the named garbage collection algorithm.</p>
1123
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1124</div>
1125
1126<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1127<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1128 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1129</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1130
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1131<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1132
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1133<p>Function attributes are set to communicate additional information about a
1134 function. Function attributes are considered to be part of the function, not
1135 of the function type, so functions with different parameter attributes can
1136 have the same function type.</p>
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 simple keywords that follow the type specified. If
1139 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1140
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1141<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1142define void @f() noinline { ... }
1143define void @f() alwaysinline { ... }
1144define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1145define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1146</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1147
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1148<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1149 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1150 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1151 the backend should forcibly align the stack pointer. Specify the
1152 desired alignment, which must be a power of two, in parentheses.
1153
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1154 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1155 <dd>This attribute indicates that the inliner should attempt to inline this
1156 function into callers whenever possible, ignoring any active inlining size
1157 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1158
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1159 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1160 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1161 meaning the function can be patched and/or hooked even while it is
1162 loaded into memory. On x86, the function prologue will be preceded
1163 by six bytes of padding and will begin with a two-byte instruction.
1164 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1165 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1166
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1167 <dt><tt><b>nonlazybind</b></tt></dt>
1168 <dd>This attribute suppresses lazy symbol binding for the function. This
1169 may make calls to the function faster, at the cost of extra program
1170 startup time if the function is not called during program startup.</dd>
1171
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1172 <dt><tt><b>inlinehint</b></tt></dt>
1173 <dd>This attribute indicates that the source code contained a hint that inlining
1174 this function is desirable (such as the "inline" keyword in C/C++). It
1175 is just a hint; it imposes no requirements on the inliner.</dd>
1176
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1177 <dt><tt><b>naked</b></tt></dt>
1178 <dd>This attribute disables prologue / epilogue emission for the function.
1179 This can have very system-specific consequences.</dd>
1180
1181 <dt><tt><b>noimplicitfloat</b></tt></dt>
1182 <dd>This attributes disables implicit floating point instructions.</dd>
1183
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1184 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1185 <dd>This attribute indicates that the inliner should never inline this
1186 function in any situation. This attribute may not be used together with
1187 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1188
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1189 <dt><tt><b>noredzone</b></tt></dt>
1190 <dd>This attribute indicates that the code generator should not use a red
1191 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1192
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1193 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1194 <dd>This function attribute indicates that the function never returns
1195 normally. This produces undefined behavior at runtime if the function
1196 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1197
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This function attribute indicates that the function never returns with an
1200 unwind or exceptional control flow. If the function does unwind, its
1201 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1202
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1203 <dt><tt><b>optsize</b></tt></dt>
1204 <dd>This attribute suggests that optimization passes and code generator passes
1205 make choices that keep the code size of this function low, and otherwise
1206 do optimizations specifically to reduce code size.</dd>
1207
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1208 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1209 <dd>This attribute indicates that the function computes its result (or decides
1210 to unwind an exception) based strictly on its arguments, without
1211 dereferencing any pointer arguments or otherwise accessing any mutable
1212 state (e.g. memory, control registers, etc) visible to caller functions.
1213 It does not write through any pointer arguments
1214 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1215 changes any state visible to callers. This means that it cannot unwind
1216 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1217 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1218
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1219 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1220 <dd>This attribute indicates that the function does not write through any
1221 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1222 arguments) or otherwise modify any state (e.g. memory, control registers,
1223 etc) visible to caller functions. It may dereference pointer arguments
1224 and read state that may be set in the caller. A readonly function always
1225 returns the same value (or unwinds an exception identically) when called
1226 with the same set of arguments and global state. It cannot unwind an
1227 exception by calling the <tt>C++</tt> exception throwing methods, but may
1228 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1229
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1230 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1231 <dd>This attribute indicates that the function should emit a stack smashing
1232 protector. It is in the form of a "canary"&mdash;a random value placed on
1233 the stack before the local variables that's checked upon return from the
1234 function to see if it has been overwritten. A heuristic is used to
1235 determine if a function needs stack protectors or not.<br>
1236<br>
1237 If a function that has an <tt>ssp</tt> attribute is inlined into a
1238 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1239 function will have an <tt>ssp</tt> attribute.</dd>
1240
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1241 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1242 <dd>This attribute indicates that the function should <em>always</em> emit a
1243 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1244 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1245<br>
1246 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1247 function that doesn't have an <tt>sspreq</tt> attribute or which has
1248 an <tt>ssp</tt> attribute, then the resulting function will have
1249 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1250</dl>
1251
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1252</div>
1253
1254<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1255<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1256 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1257</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1258
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1259<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1260
1261<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1262 the GCC "file scope inline asm" blocks. These blocks are internally
1263 concatenated by LLVM and treated as a single unit, but may be separated in
1264 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1265
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1266<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1267module asm "inline asm code goes here"
1268module asm "more can go here"
1269</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1270
1271<p>The strings can contain any character by escaping non-printable characters.
1272 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]1273 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1274
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1275<p>The inline asm code is simply printed to the machine code .s file when
1276 assembly code is generated.</p>
1277
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1278</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1279
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1280<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1281<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1282 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1283</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1284
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1285<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1286
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1287<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1288 data is to be laid out in memory. The syntax for the data layout is
1289 simply:</p>
1290
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1291<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1292target datalayout = "<i>layout specification</i>"
1293</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1294
1295<p>The <i>layout specification</i> consists of a list of specifications
1296 separated by the minus sign character ('-'). Each specification starts with
1297 a letter and may include other information after the letter to define some
1298 aspect of the data layout. The specifications accepted are as follows:</p>
1299
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1300<dl>
1301 <dt><tt>E</tt></dt>
1302 <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]1303 bits with the most significance have the lowest address location.</dd>
1304
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1305 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1306 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1307 the bits with the least significance have the lowest address
1308 location.</dd>
1309
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1310 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1311 <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]1312 <i>preferred</i> alignments. All sizes are in bits. Specifying
1313 the <i>pref</i> alignment is optional. If omitted, the
1314 preceding <tt>:</tt> should be omitted too.</dd>
1315
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1316 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1317 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1318 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1319
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1320 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1321 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1322 <i>size</i>.</dd>
1323
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1324 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1325 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1326 <i>size</i>. Only values of <i>size</i> that are supported by the target
1327 will work. 32 (float) and 64 (double) are supported on all targets;
1328 80 or 128 (different flavors of long double) are also supported on some
1329 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1330
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1331 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1332 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1333 <i>size</i>.</dd>
1334
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1335 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1336 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1337 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1338
1339 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1340 <dd>This specifies a set of native integer widths for the target CPU
1341 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1342 "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]1343 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1344 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1345</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1346
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1347<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1348 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1349 specifications in the <tt>datalayout</tt> keyword. The default specifications
1350 are given in this list:</p>
1351
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1352<ul>
1353 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1354 <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]1355 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1356 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1357 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1358 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1359 <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]1360 alignment of 64-bits</li>
1361 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1362 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1363 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1364 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1365 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1366 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1367</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1368
1369<p>When LLVM is determining the alignment for a given type, it uses the
1370 following rules:</p>
1371
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1372<ol>
1373 <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]1374 specification is used.</li>
1375
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1376 <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]1377 smallest integer type that is larger than the bitwidth of the sought type
1378 is used. If none of the specifications are larger than the bitwidth then
1379 the the largest integer type is used. For example, given the default
1380 specifications above, the i7 type will use the alignment of i8 (next
1381 largest) while both i65 and i256 will use the alignment of i64 (largest
1382 specified).</li>
1383
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1384 <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]1385 largest vector type that is smaller than the sought vector type will be
1386 used as a fall back. This happens because &lt;128 x double&gt; can be
1387 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1388</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1389
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1390</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1391
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1392<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1393<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1394 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1395</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1396
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1397<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1398
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1399<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1400with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1401is undefined. Pointer values are associated with address ranges
1402according to the following rules:</p>
1403
1404<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1405 <li>A pointer value is associated with the addresses associated with
1406 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1407 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1408 range of the variable's storage.</li>
1409 <li>The result value of an allocation instruction is associated with
1410 the address range of the allocated storage.</li>
1411 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1412 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1413 <li>An integer constant other than zero or a pointer value returned
1414 from a function not defined within LLVM may be associated with address
1415 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1416 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1417 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1418</ul>
1419
1420<p>A pointer value is <i>based</i> on another pointer value according
1421 to the following rules:</p>
1422
1423<ul>
1424 <li>A pointer value formed from a
1425 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1426 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1427 <li>The result value of a
1428 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1429 of the <tt>bitcast</tt>.</li>
1430 <li>A pointer value formed by an
1431 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1432 pointer values that contribute (directly or indirectly) to the
1433 computation of the pointer's value.</li>
1434 <li>The "<i>based</i> on" relationship is transitive.</li>
1435</ul>
1436
1437<p>Note that this definition of <i>"based"</i> is intentionally
1438 similar to the definition of <i>"based"</i> in C99, though it is
1439 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1440
1441<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1442<tt><a href="#i_load">load</a></tt> merely indicates the size and
1443alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1444interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1445<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1446and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1447
1448<p>Consequently, type-based alias analysis, aka TBAA, aka
1449<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1450LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1451additional information which specialized optimization passes may use
1452to implement type-based alias analysis.</p>
1453
1454</div>
1455
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1456<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1457<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1458 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1459</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1460
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1461<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1462
1463<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1464href="#i_store"><tt>store</tt></a>s, and <a
1465href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1466The optimizers must not change the number of volatile operations or change their
1467order of execution relative to other volatile operations. The optimizers
1468<i>may</i> change the order of volatile operations relative to non-volatile
1469operations. This is not Java's "volatile" and has no cross-thread
1470synchronization behavior.</p>
1471
1472</div>
1473
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1474</div>
1475
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1476<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1477<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1478<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1479
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1480<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1481
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1482<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1483 intermediate representation. Being typed enables a number of optimizations
1484 to be performed on the intermediate representation directly, without having
1485 to do extra analyses on the side before the transformation. A strong type
1486 system makes it easier to read the generated code and enables novel analyses
1487 and transformations that are not feasible to perform on normal three address
1488 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1489
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1490<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1491<h3>
1492 <a name="t_classifications">Type Classifications</a>
1493</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1494
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1495<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1496
1497<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1498
1499<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1500 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1501 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1502 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1503 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1504 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1505 </tr>
1506 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1507 <td><a href="#t_floating">floating point</a></td>
1508 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1509 </tr>
1510 <tr>
1511 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1512 <td><a href="#t_integer">integer</a>,
1513 <a href="#t_floating">floating point</a>,
1514 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1515 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1516 <a href="#t_struct">structure</a>,
1517 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1518 <a href="#t_label">label</a>,
1519 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1520 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1521 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1522 <tr>
1523 <td><a href="#t_primitive">primitive</a></td>
1524 <td><a href="#t_label">label</a>,
1525 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1526 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1527 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1528 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1529 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1530 </tr>
1531 <tr>
1532 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1533 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1534 <a href="#t_function">function</a>,
1535 <a href="#t_pointer">pointer</a>,
1536 <a href="#t_struct">structure</a>,
1537 <a href="#t_pstruct">packed structure</a>,
1538 <a href="#t_vector">vector</a>,
1539 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1540 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1541 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1542 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1543</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1544
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1545<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1546 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1547 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1548
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1549</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1550
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1551<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1552<h3>
1553 <a name="t_primitive">Primitive Types</a>
1554</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1555
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1556<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1557
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1558<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1559 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1560
1561<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1562<h4>
1563 <a name="t_integer">Integer Type</a>
1564</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1565
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1566<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1567
1568<h5>Overview:</h5>
1569<p>The integer type is a very simple type that simply specifies an arbitrary
1570 bit width for the integer type desired. Any bit width from 1 bit to
1571 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1572
1573<h5>Syntax:</h5>
1574<pre>
1575 iN
1576</pre>
1577
1578<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1579 value.</p>
1580
1581<h5>Examples:</h5>
1582<table class="layout">
1583 <tr class="layout">
1584 <td class="left"><tt>i1</tt></td>
1585 <td class="left">a single-bit integer.</td>
1586 </tr>
1587 <tr class="layout">
1588 <td class="left"><tt>i32</tt></td>
1589 <td class="left">a 32-bit integer.</td>
1590 </tr>
1591 <tr class="layout">
1592 <td class="left"><tt>i1942652</tt></td>
1593 <td class="left">a really big integer of over 1 million bits.</td>
1594 </tr>
1595</table>
1596
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1597</div>
1598
1599<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1600<h4>
1601 <a name="t_floating">Floating Point Types</a>
1602</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1603
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1604<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1605
1606<table>
1607 <tbody>
1608 <tr><th>Type</th><th>Description</th></tr>
1609 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1610 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1611 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1612 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1613 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1614 </tbody>
1615</table>
1616
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1617</div>
1618
1619<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1620<h4>
1621 <a name="t_x86mmx">X86mmx Type</a>
1622</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1623
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1624<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1625
1626<h5>Overview:</h5>
1627<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>
1628
1629<h5>Syntax:</h5>
1630<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1631 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1632</pre>
1633
1634</div>
1635
1636<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1637<h4>
1638 <a name="t_void">Void Type</a>
1639</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1640
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1641<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1642
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1643<h5>Overview:</h5>
1644<p>The void type does not represent any value and has no size.</p>
1645
1646<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1647<pre>
1648 void
1649</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1650
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1651</div>
1652
1653<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1654<h4>
1655 <a name="t_label">Label Type</a>
1656</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1657
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1658<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1659
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1660<h5>Overview:</h5>
1661<p>The label type represents code labels.</p>
1662
1663<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1664<pre>
1665 label
1666</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1667
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1668</div>
1669
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1670<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1671<h4>
1672 <a name="t_metadata">Metadata Type</a>
1673</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1674
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1675<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1676
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1677<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1678<p>The metadata type represents embedded metadata. No derived types may be
1679 created from metadata except for <a href="#t_function">function</a>
1680 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1681
1682<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1683<pre>
1684 metadata
1685</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1686
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1687</div>
1688
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1689</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1690
1691<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1692<h3>
1693 <a name="t_derived">Derived Types</a>
1694</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1695
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1696<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1697
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1698<p>The real power in LLVM comes from the derived types in the system. This is
1699 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1700 useful types. Each of these types contain one or more element types which
1701 may be a primitive type, or another derived type. For example, it is
1702 possible to have a two dimensional array, using an array as the element type
1703 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1704
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1705
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1706<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1707<h4>
1708 <a name="t_aggregate">Aggregate Types</a>
1709</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1710
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1711<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1712
1713<p>Aggregate Types are a subset of derived types that can contain multiple
1714 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1715 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1716 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1717
1718</div>
1719
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1720<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1721<h4>
1722 <a name="t_array">Array Type</a>
1723</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1724
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1725<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1726
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1727<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1728<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1729 sequentially in memory. The array type requires a size (number of elements)
1730 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1731
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1732<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1733<pre>
1734 [&lt;# elements&gt; x &lt;elementtype&gt;]
1735</pre>
1736
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1737<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1738 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1739
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1740<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1741<table class="layout">
1742 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1743 <td class="left"><tt>[40 x i32]</tt></td>
1744 <td class="left">Array of 40 32-bit integer values.</td>
1745 </tr>
1746 <tr class="layout">
1747 <td class="left"><tt>[41 x i32]</tt></td>
1748 <td class="left">Array of 41 32-bit integer values.</td>
1749 </tr>
1750 <tr class="layout">
1751 <td class="left"><tt>[4 x i8]</tt></td>
1752 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1753 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1754</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1755<p>Here are some examples of multidimensional arrays:</p>
1756<table class="layout">
1757 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1758 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1759 <td class="left">3x4 array of 32-bit integer values.</td>
1760 </tr>
1761 <tr class="layout">
1762 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1763 <td class="left">12x10 array of single precision floating point values.</td>
1764 </tr>
1765 <tr class="layout">
1766 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1767 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1768 </tr>
1769</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1770
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1771<p>There is no restriction on indexing beyond the end of the array implied by
1772 a static type (though there are restrictions on indexing beyond the bounds
1773 of an allocated object in some cases). This means that single-dimension
1774 'variable sized array' addressing can be implemented in LLVM with a zero
1775 length array type. An implementation of 'pascal style arrays' in LLVM could
1776 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1777
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1778</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1779
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1780<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1781<h4>
1782 <a name="t_function">Function Type</a>
1783</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1784
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1785<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1786
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1787<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1788<p>The function type can be thought of as a function signature. It consists of
1789 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]1790 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1791
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1792<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1793<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1794 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1795</pre>
1796
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1797<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]1798 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1799 which indicates that the function takes a variable number of arguments.
1800 Variable argument functions can access their arguments with
1801 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1802 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1803 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1804
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1805<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1806<table class="layout">
1807 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1808 <td class="left"><tt>i32 (i32)</tt></td>
1809 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1810 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1811 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1812 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1813 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1814 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1815 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1816 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1817 </td>
1818 </tr><tr class="layout">
1819 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1820 <td class="left">A vararg function that takes at least one
1821 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1822 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1823 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1824 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1825 </tr><tr class="layout">
1826 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1827 <td class="left">A function taking an <tt>i32</tt>, returning a
1828 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1829 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1830 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1831</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1832
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1833</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1834
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1835<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1836<h4>
1837 <a name="t_struct">Structure Type</a>
1838</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1839
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1840<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1841
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1842<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1843<p>The structure type is used to represent a collection of data members together
1844 in memory. The packing of the field types is defined to match the ABI of the
1845 underlying processor. The elements of a structure may be any type that has a
1846 size.</p>
1847
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1848<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1849 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1850 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1851 Structures in registers are accessed using the
1852 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1853 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1854<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1855<pre>
1856 { &lt;type list&gt; }
1857</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1858
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1859<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1860<table class="layout">
1861 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1862 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1863 <td class="left">A triple of three <tt>i32</tt> values</td>
1864 </tr><tr class="layout">
1865 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1866 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1867 second element is a <a href="#t_pointer">pointer</a> to a
1868 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1869 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1870 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1871</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1872
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1873</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1874
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1875<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1876<h4>
1877 <a name="t_pstruct">Packed Structure Type</a>
1878</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1879
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1880<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1881
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1882<h5>Overview:</h5>
1883<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1884 together in memory. There is no padding between fields. Further, the
1885 alignment of a packed structure is 1 byte. The elements of a packed
1886 structure may be any type that has a size.</p>
1887
1888<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1889 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1890 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1891
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1892<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1893<pre>
1894 &lt; { &lt;type list&gt; } &gt;
1895</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1896
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1897<h5>Examples:</h5>
1898<table class="layout">
1899 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1900 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1901 <td class="left">A triple of three <tt>i32</tt> values</td>
1902 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1903 <td class="left">
1904<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1905 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1906 second element is a <a href="#t_pointer">pointer</a> to a
1907 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1908 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1909 </tr>
1910</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1911
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1912</div>
1913
1914<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1915<h4>
1916 <a name="t_pointer">Pointer Type</a>
1917</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1918
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1919<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1920
1921<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]1922<p>The pointer type is used to specify memory locations.
1923 Pointers are commonly used to reference objects in memory.</p>
1924
1925<p>Pointer types may have an optional address space attribute defining the
1926 numbered address space where the pointed-to object resides. The default
1927 address space is number zero. The semantics of non-zero address
1928 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1929
1930<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1931 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1932
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1933<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1934<pre>
1935 &lt;type&gt; *
1936</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1937
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1938<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1939<table class="layout">
1940 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1941 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1942 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1943 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1944 </tr>
1945 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]1946 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1947 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1948 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1949 <tt>i32</tt>.</td>
1950 </tr>
1951 <tr class="layout">
1952 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1953 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1954 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1955 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1956</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +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 Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1960<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1961<h4>
1962 <a name="t_vector">Vector 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 Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1966
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1967<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1968<p>A vector type is a simple derived type that represents a vector of elements.
1969 Vector types are used when multiple primitive data are operated in parallel
1970 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1971 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1972 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1973
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1974<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1975<pre>
1976 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1977</pre>
1978
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]1979<p>The number of elements is a constant integer value larger than 0; elementtype
1980 may be any integer or floating point type. Vectors of size zero are not
1981 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1982
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1983<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1984<table class="layout">
1985 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1986 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1987 <td class="left">Vector of 4 32-bit integer values.</td>
1988 </tr>
1989 <tr class="layout">
1990 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1991 <td class="left">Vector of 8 32-bit floating-point values.</td>
1992 </tr>
1993 <tr class="layout">
1994 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1995 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1996 </tr>
1997</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1998
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1999</div>
2000
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2001<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2002<h4>
2003 <a name="t_opaque">Opaque Type</a>
2004</h4>
2005
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2006<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2007
2008<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2009<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2010 corresponds (for example) to the C notion of a forward declared structure
2011 type. In LLVM, opaque types can eventually be resolved to any type (not just
2012 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2013
2014<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2015<pre>
2016 opaque
2017</pre>
2018
2019<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2020<table class="layout">
2021 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2022 <td class="left"><tt>opaque</tt></td>
2023 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2024 </tr>
2025</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2026
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2027</div>
2028
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2029</div>
2030
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2031<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2032<h3>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2033 <a name="t_uprefs">Type Up-references</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2034</h3>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2035
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2036<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2037
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2038<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2039<p>An "up reference" allows you to refer to a lexically enclosing type without
2040 requiring it to have a name. For instance, a structure declaration may
2041 contain a pointer to any of the types it is lexically a member of. Example
2042 of up references (with their equivalent as named type declarations)
2043 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2044
2045<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]2046 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2047 { \2 }* %y = type { %y }*
2048 \1* %z = type %z*
2049</pre>
2050
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2051<p>An up reference is needed by the asmprinter for printing out cyclic types
2052 when there is no declared name for a type in the cycle. Because the
2053 asmprinter does not want to print out an infinite type string, it needs a
2054 syntax to handle recursive types that have no names (all names are optional
2055 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2056
2057<h5>Syntax:</h5>
2058<pre>
2059 \&lt;level&gt;
2060</pre>
2061
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2062<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2063
2064<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2065<table class="layout">
2066 <tr class="layout">
2067 <td class="left"><tt>\1*</tt></td>
2068 <td class="left">Self-referential pointer.</td>
2069 </tr>
2070 <tr class="layout">
2071 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
2072 <td class="left">Recursive structure where the upref refers to the out-most
2073 structure.</td>
2074 </tr>
2075</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2076
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2077</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2078
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2079</div>
2080
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2081<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2082<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2083<!-- *********************************************************************** -->
2084
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2085<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2086
2087<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2088 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2089
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2090<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2091<h3>
2092 <a name="simpleconstants">Simple Constants</a>
2093</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2094
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2095<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2096
2097<dl>
2098 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2099 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2100 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2101
2102 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2103 <dd>Standard integers (such as '4') are constants of
2104 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2105 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2106
2107 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2108 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2109 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2110 notation (see below). The assembler requires the exact decimal value of a
2111 floating-point constant. For example, the assembler accepts 1.25 but
2112 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2113 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2114
2115 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2116 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2117 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2118</dl>
2119
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2120<p>The one non-intuitive notation for constants is the hexadecimal form of
2121 floating point constants. For example, the form '<tt>double
2122 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2123 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2124 constants are required (and the only time that they are generated by the
2125 disassembler) is when a floating point constant must be emitted but it cannot
2126 be represented as a decimal floating point number in a reasonable number of
2127 digits. For example, NaN's, infinities, and other special values are
2128 represented in their IEEE hexadecimal format so that assembly and disassembly
2129 do not cause any bits to change in the constants.</p>
2130
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2131<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2132 represented using the 16-digit form shown above (which matches the IEEE754
2133 representation for double); float values must, however, be exactly
2134 representable as IEE754 single precision. Hexadecimal format is always used
2135 for long double, and there are three forms of long double. The 80-bit format
2136 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2137 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2138 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2139 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2140 currently supported target uses this format. Long doubles will only work if
2141 they match the long double format on your target. All hexadecimal formats
2142 are big-endian (sign bit at the left).</p>
2143
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2144<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2145</div>
2146
2147<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2148<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2149<a name="aggregateconstants"></a> <!-- old anchor -->
2150<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2151</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2152
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2153<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2154
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2155<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2156 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2157
2158<dl>
2159 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2160 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2161 type definitions (a comma separated list of elements, surrounded by braces
2162 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2163 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2164 Structure constants must have <a href="#t_struct">structure type</a>, and
2165 the number and types of elements must match those specified by the
2166 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2167
2168 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2169 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2170 definitions (a comma separated list of elements, surrounded by square
2171 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2172 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2173 the number and types of elements must match those specified by the
2174 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2175
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2176 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2177 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2178 definitions (a comma separated list of elements, surrounded by
2179 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2180 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2181 have <a href="#t_vector">vector type</a>, and the number and types of
2182 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2183
2184 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2185 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2186 value to zero of <em>any</em> type, including scalar and
2187 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2188 This is often used to avoid having to print large zero initializers
2189 (e.g. for large arrays) and is always exactly equivalent to using explicit
2190 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2191
2192 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2193 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2194 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2195 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2196 be interpreted as part of the instruction stream, metadata is a place to
2197 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2198</dl>
2199
2200</div>
2201
2202<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2203<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2204 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2205</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2206
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2207<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2208
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2209<p>The addresses of <a href="#globalvars">global variables</a>
2210 and <a href="#functionstructure">functions</a> are always implicitly valid
2211 (link-time) constants. These constants are explicitly referenced when
2212 the <a href="#identifiers">identifier for the global</a> is used and always
2213 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2214 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2215
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2216<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2217@X = global i32 17
2218@Y = global i32 42
2219@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2220</pre>
2221
2222</div>
2223
2224<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2225<h3>
2226 <a name="undefvalues">Undefined Values</a>
2227</h3>
2228
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2229<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2230
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2231<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]2232 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2233 Undefined values may be of any type (other than '<tt>label</tt>'
2234 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2235
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2236<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2237 program is well defined no matter what value is used. This gives the
2238 compiler more freedom to optimize. Here are some examples of (potentially
2239 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2240
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2241
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2242<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2243 %A = add %X, undef
2244 %B = sub %X, undef
2245 %C = xor %X, undef
2246Safe:
2247 %A = undef
2248 %B = undef
2249 %C = undef
2250</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2251
2252<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]2253 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]2254
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2255<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2256 %A = or %X, undef
2257 %B = and %X, undef
2258Safe:
2259 %A = -1
2260 %B = 0
2261Unsafe:
2262 %A = undef
2263 %B = undef
2264</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2265
2266<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2267 For example, if <tt>%X</tt> has a zero bit, then the output of the
2268 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2269 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2270 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2271 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2272 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2273 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2274 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2275
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2276<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2277 %A = select undef, %X, %Y
2278 %B = select undef, 42, %Y
2279 %C = select %X, %Y, undef
2280Safe:
2281 %A = %X (or %Y)
2282 %B = 42 (or %Y)
2283 %C = %Y
2284Unsafe:
2285 %A = undef
2286 %B = undef
2287 %C = undef
2288</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2289
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2290<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2291 branch) conditions can go <em>either way</em>, but they have to come from one
2292 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2293 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2294 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2295 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2296 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2297 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2298
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2299<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2300 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2301
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2302 %B = undef
2303 %C = xor %B, %B
2304
2305 %D = undef
2306 %E = icmp lt %D, 4
2307 %F = icmp gte %D, 4
2308
2309Safe:
2310 %A = undef
2311 %B = undef
2312 %C = undef
2313 %D = undef
2314 %E = undef
2315 %F = undef
2316</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2317
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2318<p>This example points out that two '<tt>undef</tt>' operands are not
2319 necessarily the same. This can be surprising to people (and also matches C
2320 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2321 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2322 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2323 its value over its "live range". This is true because the variable doesn't
2324 actually <em>have a live range</em>. Instead, the value is logically read
2325 from arbitrary registers that happen to be around when needed, so the value
2326 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2327 need to have the same semantics or the core LLVM "replace all uses with"
2328 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2329
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2330<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2331 %A = fdiv undef, %X
2332 %B = fdiv %X, undef
2333Safe:
2334 %A = undef
2335b: unreachable
2336</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2337
2338<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2339 value</em> and <em>undefined behavior</em>. An undefined value (like
2340 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2341 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2342 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2343 defined on SNaN's. However, in the second example, we can make a more
2344 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2345 arbitrary value, we are allowed to assume that it could be zero. Since a
2346 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2347 the operation does not execute at all. This allows us to delete the divide and
2348 all code after it. Because the undefined operation "can't happen", the
2349 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2350
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2351<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2352a: store undef -> %X
2353b: store %X -> undef
2354Safe:
2355a: &lt;deleted&gt;
2356b: unreachable
2357</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2358
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2359<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2360 undefined value can be assumed to not have any effect; we can assume that the
2361 value is overwritten with bits that happen to match what was already there.
2362 However, a store <em>to</em> an undefined location could clobber arbitrary
2363 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2364
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2365</div>
2366
2367<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2368<h3>
2369 <a name="trapvalues">Trap Values</a>
2370</h3>
2371
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2372<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2373
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2374<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2375 instead of representing an unspecified bit pattern, they represent the
2376 fact that an instruction or constant expression which cannot evoke side
2377 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2378 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2379
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2380<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]2381 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2382 <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]2383
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2384<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2385
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2386<ul>
2387<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2388 their operands.</li>
2389
2390<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2391 to their dynamic predecessor basic block.</li>
2392
2393<li>Function arguments depend on the corresponding actual argument values in
2394 the dynamic callers of their functions.</li>
2395
2396<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2397 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2398 control back to them.</li>
2399
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2400<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2401 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2402 or exception-throwing call instructions that dynamically transfer control
2403 back to them.</li>
2404
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2405<li>Non-volatile loads and stores depend on the most recent stores to all of the
2406 referenced memory addresses, following the order in the IR
2407 (including loads and stores implied by intrinsics such as
2408 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2409
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2410<!-- TODO: In the case of multiple threads, this only applies if the store
2411 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2412
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2413<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2414
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2415<li>An instruction with externally visible side effects depends on the most
2416 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2417 the order in the IR. (This includes
2418 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2419
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2420<li>An instruction <i>control-depends</i> on a
2421 <a href="#terminators">terminator instruction</a>
2422 if the terminator instruction has multiple successors and the instruction
2423 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2424 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2425
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2426<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2427 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2428 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2429 successor.</li>
2430
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2431<li>Dependence is transitive.</li>
2432
2433</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2434
2435<p>Whenever a trap value is generated, all values which depend on it evaluate
2436 to trap. If they have side effects, the evoke their side effects as if each
2437 operand with a trap value were undef. If they have externally-visible side
2438 effects, the behavior is undefined.</p>
2439
2440<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2441
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2442<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2443entry:
2444 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2445 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2446 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2447 store i32 0, i32* %trap_yet_again ; undefined behavior
2448
2449 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2450 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2451
2452 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2453
2454 %narrowaddr = bitcast i32* @g to i16*
2455 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2456 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2457 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2458
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2459 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2460 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2461
2462true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2463 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2464 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2465 br label %end
2466
2467end:
2468 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2469 ; Both edges into this PHI are
2470 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2471 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2472
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2473 volatile store i32 0, i32* @g ; This would depend on the store in %true
2474 ; if %cmp is true, or the store in %entry
2475 ; otherwise, so this is undefined behavior.
2476
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2477 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2478 ; The same branch again, but this time the
2479 ; true block doesn't have side effects.
2480
2481second_true:
2482 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2483 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2484
2485second_end:
2486 volatile store i32 0, i32* @g ; This time, the instruction always depends
2487 ; on the store in %end. Also, it is
2488 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2489 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2490 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2491</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2492
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2493</div>
2494
2495<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2496<h3>
2497 <a name="blockaddress">Addresses of Basic Blocks</a>
2498</h3>
2499
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2500<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2501
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2502<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2503
2504<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2505 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2506 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2507
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2508<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2509 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2510 comparisons against null. Pointer equality tests between labels addresses
2511 results in undefined behavior &mdash; though, again, comparison against null
2512 is ok, and no label is equal to the null pointer. This may be passed around
2513 as an opaque pointer sized value as long as the bits are not inspected. This
2514 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2515 long as the original value is reconstituted before the <tt>indirectbr</tt>
2516 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2517
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2518<p>Finally, some targets may provide defined semantics when using the value as
2519 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2520
2521</div>
2522
2523
2524<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2525<h3>
2526 <a name="constantexprs">Constant Expressions</a>
2527</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2528
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2529<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2530
2531<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2532 to be used as constants. Constant expressions may be of
2533 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2534 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2535 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2536
2537<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2538 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2539 <dd>Truncate a constant to another type. The bit size of CST must be larger
2540 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2541
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2542 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2543 <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]2544 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2545
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2546 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2547 <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]2548 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2549
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2550 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2551 <dd>Truncate a floating point constant to another floating point type. The
2552 size of CST must be larger than the size of TYPE. Both types must be
2553 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2554
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2555 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2556 <dd>Floating point extend a constant to another type. The size of CST must be
2557 smaller or equal to the size of TYPE. Both types must be floating
2558 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2559
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2560 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2561 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2562 constant. TYPE must be a scalar or vector integer type. CST must be of
2563 scalar or vector floating point type. Both CST and TYPE must be scalars,
2564 or vectors of the same number of elements. If the value won't fit in the
2565 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2566
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2567 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2568 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2569 constant. TYPE must be a scalar or vector integer type. CST must be of
2570 scalar or vector floating point type. Both CST and TYPE must be scalars,
2571 or vectors of the same number of elements. If the value won't fit in the
2572 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2573
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2574 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2575 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2576 constant. TYPE must be a scalar or vector floating point type. CST must be
2577 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2578 vectors of the same number of elements. If the value won't fit in the
2579 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2580
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2581 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2582 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2583 constant. TYPE must be a scalar or vector floating point type. CST must be
2584 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2585 vectors of the same number of elements. If the value won't fit in the
2586 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2587
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2588 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2589 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2590 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2591 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2592 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2593
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2594 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2595 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2596 type. CST must be of integer type. The CST value is zero extended,
2597 truncated, or unchanged to make it fit in a pointer size. This one is
2598 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2599
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2600 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2601 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2602 are the same as those for the <a href="#i_bitcast">bitcast
2603 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2604
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2605 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2606 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2607 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2608 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2609 instruction, the index list may have zero or more indexes, which are
2610 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2611
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2612 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2613 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2614
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2615 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2616 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2617
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2618 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2619 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2620
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2621 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2622 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2623 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2624
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2625 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2626 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2627 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2628
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2629 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2630 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2631 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2632
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2633 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2634 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2635 constants. The index list is interpreted in a similar manner as indices in
2636 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2637 index value must be specified.</dd>
2638
2639 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2640 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2641 constants. The index list is interpreted in a similar manner as indices in
2642 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2643 index value must be specified.</dd>
2644
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2645 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2646 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2647 be any of the <a href="#binaryops">binary</a>
2648 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2649 on operands are the same as those for the corresponding instruction
2650 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2651</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2652
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2653</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2654
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2655</div>
2656
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2657<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2658<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2659<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2660<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2661<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2662<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2663<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2664</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2665
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2666<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2667
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2668<p>LLVM supports inline assembler expressions (as opposed
2669 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2670 a special value. This value represents the inline assembler as a string
2671 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2672 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2673 expression has side effects, and a flag indicating whether the function
2674 containing the asm needs to align its stack conservatively. An example
2675 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2676
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2677<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2678i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2679</pre>
2680
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2681<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2682 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2683 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2684
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2685<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2686%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]2687</pre>
2688
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2689<p>Inline asms with side effects not visible in the constraint list must be
2690 marked as having side effects. This is done through the use of the
2691 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2692
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2693<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2694call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2695</pre>
2696
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2697<p>In some cases inline asms will contain code that will not work unless the
2698 stack is aligned in some way, such as calls or SSE instructions on x86,
2699 yet will not contain code that does that alignment within the asm.
2700 The compiler should make conservative assumptions about what the asm might
2701 contain and should generate its usual stack alignment code in the prologue
2702 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2703
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2704<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2705call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2706</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2707
2708<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2709 first.</p>
2710
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2711<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2712 documented here. Constraints on what can be done (e.g. duplication, moving,
2713 etc need to be documented). This is probably best done by reference to
2714 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2715
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2716<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2717<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2718</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2719
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2720<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2721
2722<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2723 attached to it that contains a list of constant integers. If present, the
2724 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2725 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2726 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2727 source code that produced it. For example:</p>
2728
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2729<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2730call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2731...
2732!42 = !{ i32 1234567 }
2733</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2734
2735<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]2736 IR. If the MDNode contains multiple constants, the code generator will use
2737 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]2738
2739</div>
2740
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2741</div>
2742
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2743<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2744<h3>
2745 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2746</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2747
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2748<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2749
2750<p>LLVM IR allows metadata to be attached to instructions in the program that
2751 can convey extra information about the code to the optimizers and code
2752 generator. One example application of metadata is source-level debug
2753 information. There are two metadata primitives: strings and nodes. All
2754 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2755 preceding exclamation point ('<tt>!</tt>').</p>
2756
2757<p>A metadata string is a string surrounded by double quotes. It can contain
2758 any character by escaping non-printable characters with "\xx" where "xx" is
2759 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2760
2761<p>Metadata nodes are represented with notation similar to structure constants
2762 (a comma separated list of elements, surrounded by braces and preceded by an
2763 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2764 10}</tt>". Metadata nodes can have any values as their operand.</p>
2765
2766<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2767 metadata nodes, which can be looked up in the module symbol table. For
2768 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2769
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2770<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2771 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2772
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2773<div class="doc_code">
2774<pre>
2775call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2776</pre>
2777</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2778
2779<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2780 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2781
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2782<div class="doc_code">
2783<pre>
2784%indvar.next = add i64 %indvar, 1, !dbg !21
2785</pre>
2786</div>
2787
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2788</div>
2789
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2790</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2791
2792<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2793<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2794 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2795</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2796<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2797<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2798<p>LLVM has a number of "magic" global variables that contain data that affect
2799code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2800of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2801section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2802by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2803
2804<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2805<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2806<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2807</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2808
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2809<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2810
2811<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2812href="#linkage_appending">appending linkage</a>. This array contains a list of
2813pointers to global variables and functions which may optionally have a pointer
2814cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2815
2816<pre>
2817 @X = global i8 4
2818 @Y = global i32 123
2819
2820 @llvm.used = appending global [2 x i8*] [
2821 i8* @X,
2822 i8* bitcast (i32* @Y to i8*)
2823 ], section "llvm.metadata"
2824</pre>
2825
2826<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2827compiler, assembler, and linker are required to treat the symbol as if there is
2828a reference to the global that it cannot see. For example, if a variable has
2829internal linkage and no references other than that from the <tt>@llvm.used</tt>
2830list, it cannot be deleted. This is commonly used to represent references from
2831inline asms and other things the compiler cannot "see", and corresponds to
2832"attribute((used))" in GNU C.</p>
2833
2834<p>On some targets, the code generator must emit a directive to the assembler or
2835object file to prevent the assembler and linker from molesting the symbol.</p>
2836
2837</div>
2838
2839<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2840<h3>
2841 <a name="intg_compiler_used">
2842 The '<tt>llvm.compiler.used</tt>' Global Variable
2843 </a>
2844</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2845
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2846<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2847
2848<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2849<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2850touching the symbol. On targets that support it, this allows an intelligent
2851linker to optimize references to the symbol without being impeded as it would be
2852by <tt>@llvm.used</tt>.</p>
2853
2854<p>This is a rare construct that should only be used in rare circumstances, and
2855should not be exposed to source languages.</p>
2856
2857</div>
2858
2859<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2860<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2861<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2862</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2863
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2864<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2865<pre>
2866%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2867@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2868</pre>
2869<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.
2870</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2871
2872</div>
2873
2874<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2875<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2876<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2877</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2878
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2879<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2880<pre>
2881%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2882@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2883</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2884
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2885<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.
2886</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2887
2888</div>
2889
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2890</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2891
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2892<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2893<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2894<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2895
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2896<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2897
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2898<p>The LLVM instruction set consists of several different classifications of
2899 instructions: <a href="#terminators">terminator
2900 instructions</a>, <a href="#binaryops">binary instructions</a>,
2901 <a href="#bitwiseops">bitwise binary instructions</a>,
2902 <a href="#memoryops">memory instructions</a>, and
2903 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2904
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2905<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2906<h3>
2907 <a name="terminators">Terminator Instructions</a>
2908</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2909
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2910<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2911
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2912<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2913 in a program ends with a "Terminator" instruction, which indicates which
2914 block should be executed after the current block is finished. These
2915 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2916 control flow, not values (the one exception being the
2917 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2918
Duncan Sands626b0242010-04-15 20:35:54 +0000[diff] [blame]2919<p>There are seven different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2920 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2921 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2922 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2923 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2924 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2925 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2926 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2927
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2928<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2929<h4>
2930 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2931</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2932
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2933<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2934
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2935<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2936<pre>
2937 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]2938 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2939</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2940
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2941<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2942<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2943 a value) from a function back to the caller.</p>
2944
2945<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2946 value and then causes control flow, and one that just causes control flow to
2947 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2948
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2949<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2950<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2951 return value. The type of the return value must be a
2952 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2953
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2954<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2955 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2956 value or a return value with a type that does not match its type, or if it
2957 has a void return type and contains a '<tt>ret</tt>' instruction with a
2958 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2959
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2960<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2961<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2962 the calling function's context. If the caller is a
2963 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2964 instruction after the call. If the caller was an
2965 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2966 the beginning of the "normal" destination block. If the instruction returns
2967 a value, that value shall set the call or invoke instruction's return
2968 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2969
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2970<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2971<pre>
2972 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2973 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2974 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]2975</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2976
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2977</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2978<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2979<h4>
2980 <a name="i_br">'<tt>br</tt>' Instruction</a>
2981</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2982
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2983<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2984
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2985<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2986<pre>
2987 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2988</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2989
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2990<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2991<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2992 different basic block in the current function. There are two forms of this
2993 instruction, corresponding to a conditional branch and an unconditional
2994 branch.</p>
2995
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2996<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2997<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2998 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2999 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3000 target.</p>
3001
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3002<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3003<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3004 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3005 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3006 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3007
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3008<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3009<pre>
3010Test:
3011 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3012 br i1 %cond, label %IfEqual, label %IfUnequal
3013IfEqual:
3014 <a href="#i_ret">ret</a> i32 1
3015IfUnequal:
3016 <a href="#i_ret">ret</a> i32 0
3017</pre>
3018
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3019</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3020
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3021<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3022<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3023 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3024</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3025
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3026<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3027
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3028<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3029<pre>
3030 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3031</pre>
3032
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3033<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3034<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]3035 several different places. It is a generalization of the '<tt>br</tt>'
3036 instruction, allowing a branch to occur to one of many possible
3037 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3038
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3039<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3040<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3041 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3042 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3043 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3044
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3045<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3046<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3047 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3048 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3049 transferred to the corresponding destination; otherwise, control flow is
3050 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3051
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3052<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3053<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3054 <tt>switch</tt> instruction, this instruction may be code generated in
3055 different ways. For example, it could be generated as a series of chained
3056 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3057
3058<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3059<pre>
3060 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3061 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3062 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3063
3064 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3065 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3066
3067 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3068 switch i32 %val, label %otherwise [ i32 0, label %onzero
3069 i32 1, label %onone
3070 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3071</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3072
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3073</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3074
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3075
3076<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3077<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3078 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3079</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3080
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3081<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3082
3083<h5>Syntax:</h5>
3084<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3085 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]3086</pre>
3087
3088<h5>Overview:</h5>
3089
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3090<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3091 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3092 "<tt>address</tt>". Address must be derived from a <a
3093 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3094
3095<h5>Arguments:</h5>
3096
3097<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3098 rest of the arguments indicate the full set of possible destinations that the
3099 address may point to. Blocks are allowed to occur multiple times in the
3100 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3101
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3102<p>This destination list is required so that dataflow analysis has an accurate
3103 understanding of the CFG.</p>
3104
3105<h5>Semantics:</h5>
3106
3107<p>Control transfers to the block specified in the address argument. All
3108 possible destination blocks must be listed in the label list, otherwise this
3109 instruction has undefined behavior. This implies that jumps to labels
3110 defined in other functions have undefined behavior as well.</p>
3111
3112<h5>Implementation:</h5>
3113
3114<p>This is typically implemented with a jump through a register.</p>
3115
3116<h5>Example:</h5>
3117<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3118 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3119</pre>
3120
3121</div>
3122
3123
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3124<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3125<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3126 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3127</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3128
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3129<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3130
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3131<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3132<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3133 &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]3134 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3135</pre>
3136
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3137<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3138<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3139 function, with the possibility of control flow transfer to either the
3140 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3141 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3142 control flow will return to the "normal" label. If the callee (or any
3143 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3144 instruction, control is interrupted and continued at the dynamically nearest
3145 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3146
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3147<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3148<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3149
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3150<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3151 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3152 convention</a> the call should use. If none is specified, the call
3153 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3154
3155 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3156 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3157 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3158
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3159 <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]3160 function value being invoked. In most cases, this is a direct function
3161 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3162 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3163
3164 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3165 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3166
3167 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3168 signature argument types and parameter attributes. All arguments must be
3169 of <a href="#t_firstclass">first class</a> type. If the function
3170 signature indicates the function accepts a variable number of arguments,
3171 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3172
3173 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3174 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3175
3176 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3177 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3178
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3179 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3180 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3181 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3182</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3183
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3184<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3185<p>This instruction is designed to operate as a standard
3186 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3187 primary difference is that it establishes an association with a label, which
3188 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3189
3190<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3191 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3192 exception. Additionally, this is important for implementation of
3193 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3194
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3195<p>For the purposes of the SSA form, the definition of the value returned by the
3196 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3197 block to the "normal" label. If the callee unwinds then no return value is
3198 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3199
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3200<p>Note that the code generator does not yet completely support unwind, and
3201that the invoke/unwind semantics are likely to change in future versions.</p>
3202
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3203<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3204<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3205 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3206 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3207 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3208 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3209</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3210
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3211</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3212
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3213<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3214
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3215<h4>
3216 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3217</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3218
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3219<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3220
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3221<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3222<pre>
3223 unwind
3224</pre>
3225
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3226<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3227<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3228 at the first callee in the dynamic call stack which used
3229 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3230 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3231
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3232<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3233<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3234 immediately halt. The dynamic call stack is then searched for the
3235 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3236 Once found, execution continues at the "exceptional" destination block
3237 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3238 instruction in the dynamic call chain, undefined behavior results.</p>
3239
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3240<p>Note that the code generator does not yet completely support unwind, and
3241that the invoke/unwind semantics are likely to change in future versions.</p>
3242
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3243</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3244
3245<!-- _______________________________________________________________________ -->
3246
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3247<h4>
3248 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3249</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3250
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3251<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3252
3253<h5>Syntax:</h5>
3254<pre>
3255 unreachable
3256</pre>
3257
3258<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3259<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3260 instruction is used to inform the optimizer that a particular portion of the
3261 code is not reachable. This can be used to indicate that the code after a
3262 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3263
3264<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3265<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3266
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3267</div>
3268
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3269</div>
3270
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3271<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3272<h3>
3273 <a name="binaryops">Binary Operations</a>
3274</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3275
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3276<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3277
3278<p>Binary operators are used to do most of the computation in a program. They
3279 require two operands of the same type, execute an operation on them, and
3280 produce a single value. The operands might represent multiple data, as is
3281 the case with the <a href="#t_vector">vector</a> data type. The result value
3282 has the same type as its operands.</p>
3283
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3284<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3285
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3286<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3287<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3288 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3289</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3290
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3291<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3292
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3293<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3294<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3295 &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]3296 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3297 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3298 &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]3299</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3300
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3301<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3302<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3303
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3304<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3305<p>The two arguments to the '<tt>add</tt>' instruction must
3306 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3307 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3308
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3309<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3310<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3311
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3312<p>If the sum has unsigned overflow, the result returned is the mathematical
3313 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]3314
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3315<p>Because LLVM integers use a two's complement representation, this instruction
3316 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3317
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3318<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3319 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3320 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3321 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3322 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3323
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3324<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3325<pre>
3326 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3327</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3328
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3329</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3330
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3331<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3332<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3333 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3334</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3335
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3336<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3337
3338<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3339<pre>
3340 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3341</pre>
3342
3343<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3344<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3345
3346<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3347<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3348 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3349 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3350
3351<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3352<p>The value produced is the floating point sum of the two operands.</p>
3353
3354<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3355<pre>
3356 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3357</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3358
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3359</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3360
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3361<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3362<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3363 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3364</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3365
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3366<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3367
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3368<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3369<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3370 &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]3371 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3372 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3373 &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]3374</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3375
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3376<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3377<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3378 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3379
3380<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3381 '<tt>neg</tt>' instruction present in most other intermediate
3382 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3383
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3385<p>The two arguments to the '<tt>sub</tt>' instruction must
3386 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3387 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3388
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3389<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3390<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3391
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3392<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3393 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3394 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3395
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3396<p>Because LLVM integers use a two's complement representation, this instruction
3397 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3398
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3399<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3400 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3401 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3402 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3403 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3404
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3405<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3406<pre>
3407 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3408 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3409</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3410
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3411</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3412
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3413<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3414<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3415 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3416</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3417
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3418<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3419
3420<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3421<pre>
3422 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3423</pre>
3424
3425<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3426<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3427 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3428
3429<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3430 '<tt>fneg</tt>' instruction present in most other intermediate
3431 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3432
3433<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3434<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3435 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3436 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3437
3438<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3439<p>The value produced is the floating point difference of the two operands.</p>
3440
3441<h5>Example:</h5>
3442<pre>
3443 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3444 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3445</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3446
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3447</div>
3448
3449<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3450<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3451 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3452</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3453
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3454<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3455
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3456<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3457<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3458 &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]3459 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3460 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3461 &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]3462</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3463
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3464<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3465<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3466
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3467<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3468<p>The two arguments to the '<tt>mul</tt>' instruction must
3469 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3470 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3471
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3472<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3473<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3474
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3475<p>If the result of the multiplication has unsigned overflow, the result
3476 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3477 width of the result.</p>
3478
3479<p>Because LLVM integers use a two's complement representation, and the result
3480 is the same width as the operands, this instruction returns the correct
3481 result for both signed and unsigned integers. If a full product
3482 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3483 be sign-extended or zero-extended as appropriate to the width of the full
3484 product.</p>
3485
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3486<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3487 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3488 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3489 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3490 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3491
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3492<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3493<pre>
3494 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3495</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3496
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3497</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3498
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3499<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3500<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3501 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3502</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3503
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3504<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3505
3506<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3507<pre>
3508 &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]3509</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3510
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3511<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3512<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3513
3514<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3515<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3516 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3517 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3518
3519<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3520<p>The value produced is the floating point product of the two operands.</p>
3521
3522<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3523<pre>
3524 &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]3525</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3526
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3527</div>
3528
3529<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3530<h4>
3531 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3532</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3533
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3534<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3535
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3536<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3537<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3538 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3539 &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]3540</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3541
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3542<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3543<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3544
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3545<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3546<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3547 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3548 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3549
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3550<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3551<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3552
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3553<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3554 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3555
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3556<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3557
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3558<p>If the <tt>exact</tt> keyword is present, the result value of the
3559 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3560 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3561
3562
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3563<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3564<pre>
3565 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3566</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3567
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3568</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3569
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3570<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3571<h4>
3572 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3573</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3574
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3575<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3576
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3577<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3578<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3579 &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]3580 &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]3581</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3582
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3583<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3584<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3585
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3586<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3587<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3588 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3589 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3590
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3591<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3592<p>The value produced is the signed integer quotient of the two operands rounded
3593 towards zero.</p>
3594
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3595<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3596 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3597
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3598<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3599 undefined behavior; this is a rare case, but can occur, for example, by doing
3600 a 32-bit division of -2147483648 by -1.</p>
3601
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3602<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3603 <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]3604 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3605
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3606<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3607<pre>
3608 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3609</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3610
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3611</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3612
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3613<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3614<h4>
3615 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3616</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3617
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3618<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3619
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3620<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3621<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3622 &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]3623</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3624
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3625<h5>Overview:</h5>
3626<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3627
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3628<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3629<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3630 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3631 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3632
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3633<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3634<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3635
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3636<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3637<pre>
3638 &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]3639</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3640
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3641</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3642
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3643<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3644<h4>
3645 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3646</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3647
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3648<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3649
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3650<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3651<pre>
3652 &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]3653</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3654
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3655<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3656<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3657 division of its two arguments.</p>
3658
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3659<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3660<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3661 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3662 values. Both arguments must have identical types.</p>
3663
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3664<h5>Semantics:</h5>
3665<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3666 This instruction always performs an unsigned division to get the
3667 remainder.</p>
3668
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3669<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3670 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3671
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3672<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3673
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3674<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3675<pre>
3676 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3677</pre>
3678
3679</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3680
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3681<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3682<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3683 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3684</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3685
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3686<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3687
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3688<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3689<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3690 &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]3691</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3692
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3693<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3694<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3695 division of its two operands. This instruction can also take
3696 <a href="#t_vector">vector</a> versions of the values in which case the
3697 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3698
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3699<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3700<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3701 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3702 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3703
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3704<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3705<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3706 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3707 <i>modulo</i> operator (where the result is either zero or has the same sign
3708 as the divisor, <tt>op2</tt>) of a value.
3709 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3710 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3711 Math Forum</a>. For a table of how this is implemented in various languages,
3712 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3713 Wikipedia: modulo operation</a>.</p>
3714
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3715<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3716 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3717
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3718<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3719 Overflow also leads to undefined behavior; this is a rare case, but can
3720 occur, for example, by taking the remainder of a 32-bit division of
3721 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3722 lets srem be implemented using instructions that return both the result of
3723 the division and the remainder.)</p>
3724
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3725<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3726<pre>
3727 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3728</pre>
3729
3730</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3731
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3732<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3733<h4>
3734 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3735</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3736
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3737<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3738
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3739<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3740<pre>
3741 &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]3742</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3743
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3744<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3745<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3746 its two operands.</p>
3747
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3748<h5>Arguments:</h5>
3749<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3750 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3751 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3752
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3753<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3754<p>This instruction returns the <i>remainder</i> of a division. The remainder
3755 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3756
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3757<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3758<pre>
3759 &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]3760</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3761
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3762</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3763
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3764</div>
3765
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3766<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3767<h3>
3768 <a name="bitwiseops">Bitwise Binary Operations</a>
3769</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3770
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3771<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3772
3773<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3774 program. They are generally very efficient instructions and can commonly be
3775 strength reduced from other instructions. They require two operands of the
3776 same type, execute an operation on them, and produce a single value. The
3777 resulting value is the same type as its operands.</p>
3778
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3779<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3780<h4>
3781 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3782</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3783
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3784<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3785
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3786<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3787<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3788 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3789 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3790 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3791 &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]3792</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3793
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3794<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3795<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3796 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3797
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3798<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3799<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3800 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3801 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3802
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3803<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3804<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3805 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3806 is (statically or dynamically) negative or equal to or larger than the number
3807 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3808 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3809 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3810
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3811<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3812 <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]3813 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3814 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3815 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3816 they would if the shift were expressed as a mul instruction with the same
3817 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3818
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3819<h5>Example:</h5>
3820<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3821 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3822 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3823 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3824 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3825 &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]3826</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3827
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3828</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3829
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3830<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3831<h4>
3832 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3833</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3834
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3835<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3836
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3837<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3838<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3839 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3840 &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]3841</pre>
3842
3843<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3844<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3845 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3846
3847<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3848<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3849 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3850 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3851
3852<h5>Semantics:</h5>
3853<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3854 significant bits of the result will be filled with zero bits after the shift.
3855 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3856 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3857 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3858 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3859
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3860<p>If the <tt>exact</tt> keyword is present, the result value of the
3861 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3862 shifted out are non-zero.</p>
3863
3864
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3865<h5>Example:</h5>
3866<pre>
3867 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3868 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3869 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3870 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3871 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3872 &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]3873</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3874
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3875</div>
3876
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3877<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3878<h4>
3879 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3880</h4>
3881
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3882<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3883
3884<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3885<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3886 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3887 &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]3888</pre>
3889
3890<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3891<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3892 operand shifted to the right a specified number of bits with sign
3893 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3894
3895<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3896<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3897 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3898 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3899
3900<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3901<p>This instruction always performs an arithmetic shift right operation, The
3902 most significant bits of the result will be filled with the sign bit
3903 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3904 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3905 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3906 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3907
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3908<p>If the <tt>exact</tt> keyword is present, the result value of the
3909 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3910 shifted out are non-zero.</p>
3911
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3912<h5>Example:</h5>
3913<pre>
3914 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3915 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3916 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3917 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3918 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3919 &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]3920</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3921
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3922</div>
3923
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3924<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3925<h4>
3926 <a name="i_and">'<tt>and</tt>' Instruction</a>
3927</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3928
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3929<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3930
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3931<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3932<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3933 &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]3934</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3935
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3936<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3937<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3938 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3939
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3940<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3941<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3942 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3943 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3944
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3945<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3946<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3947
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3948<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3949 <tbody>
3950 <tr>
3951 <td>In0</td>
3952 <td>In1</td>
3953 <td>Out</td>
3954 </tr>
3955 <tr>
3956 <td>0</td>
3957 <td>0</td>
3958 <td>0</td>
3959 </tr>
3960 <tr>
3961 <td>0</td>
3962 <td>1</td>
3963 <td>0</td>
3964 </tr>
3965 <tr>
3966 <td>1</td>
3967 <td>0</td>
3968 <td>0</td>
3969 </tr>
3970 <tr>
3971 <td>1</td>
3972 <td>1</td>
3973 <td>1</td>
3974 </tr>
3975 </tbody>
3976</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3977
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3978<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3979<pre>
3980 &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]3981 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3982 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3983</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3984</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3985<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3986<h4>
3987 <a name="i_or">'<tt>or</tt>' Instruction</a>
3988</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3989
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3990<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3991
3992<h5>Syntax:</h5>
3993<pre>
3994 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3995</pre>
3996
3997<h5>Overview:</h5>
3998<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3999 two operands.</p>
4000
4001<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4002<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4003 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4004 values. Both arguments must have identical types.</p>
4005
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4006<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4007<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4008
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4009<table border="1" cellspacing="0" cellpadding="4">
4010 <tbody>
4011 <tr>
4012 <td>In0</td>
4013 <td>In1</td>
4014 <td>Out</td>
4015 </tr>
4016 <tr>
4017 <td>0</td>
4018 <td>0</td>
4019 <td>0</td>
4020 </tr>
4021 <tr>
4022 <td>0</td>
4023 <td>1</td>
4024 <td>1</td>
4025 </tr>
4026 <tr>
4027 <td>1</td>
4028 <td>0</td>
4029 <td>1</td>
4030 </tr>
4031 <tr>
4032 <td>1</td>
4033 <td>1</td>
4034 <td>1</td>
4035 </tr>
4036 </tbody>
4037</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4038
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4039<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4040<pre>
4041 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4042 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4043 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4044</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4045
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4046</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4047
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4048<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4049<h4>
4050 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4051</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4052
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4053<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4054
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4055<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4056<pre>
4057 &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]4058</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4059
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4060<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4061<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4062 its two operands. The <tt>xor</tt> is used to implement the "one's
4063 complement" operation, which is the "~" operator in C.</p>
4064
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4065<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4066<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4067 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4068 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4069
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4070<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4071<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4072
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4073<table border="1" cellspacing="0" cellpadding="4">
4074 <tbody>
4075 <tr>
4076 <td>In0</td>
4077 <td>In1</td>
4078 <td>Out</td>
4079 </tr>
4080 <tr>
4081 <td>0</td>
4082 <td>0</td>
4083 <td>0</td>
4084 </tr>
4085 <tr>
4086 <td>0</td>
4087 <td>1</td>
4088 <td>1</td>
4089 </tr>
4090 <tr>
4091 <td>1</td>
4092 <td>0</td>
4093 <td>1</td>
4094 </tr>
4095 <tr>
4096 <td>1</td>
4097 <td>1</td>
4098 <td>0</td>
4099 </tr>
4100 </tbody>
4101</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4102
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4103<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4104<pre>
4105 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4106 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4107 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4108 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4109</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4110
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4111</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4112
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4113</div>
4114
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4115<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4116<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4117 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4118</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4119
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4120<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4121
4122<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4123 target-independent manner. These instructions cover the element-access and
4124 vector-specific operations needed to process vectors effectively. While LLVM
4125 does directly support these vector operations, many sophisticated algorithms
4126 will want to use target-specific intrinsics to take full advantage of a
4127 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4128
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4129<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4130<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4131 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4132</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4133
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4134<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4135
4136<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4137<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4138 &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]4139</pre>
4140
4141<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4142<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4143 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4144
4145
4146<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4147<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4148 of <a href="#t_vector">vector</a> type. The second operand is an index
4149 indicating the position from which to extract the element. The index may be
4150 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4151
4152<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4153<p>The result is a scalar of the same type as the element type of
4154 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4155 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4156 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4157
4158<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4159<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4160 &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]4161</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4162
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4163</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4164
4165<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4166<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4167 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4168</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4169
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4170<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4171
4172<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4173<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4174 &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]4175</pre>
4176
4177<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4178<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4179 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4180
4181<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4182<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4183 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4184 whose type must equal the element type of the first operand. The third
4185 operand is an index indicating the position at which to insert the value.
4186 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4187
4188<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4189<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4190 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4191 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4192 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4193
4194<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4195<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4196 &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]4197</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4198
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4199</div>
4200
4201<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4202<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4203 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4204</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4205
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4206<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4207
4208<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4209<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4210 &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]4211</pre>
4212
4213<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4214<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4215 from two input vectors, returning a vector with the same element type as the
4216 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4217
4218<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4219<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4220 with types that match each other. The third argument is a shuffle mask whose
4221 element type is always 'i32'. The result of the instruction is a vector
4222 whose length is the same as the shuffle mask and whose element type is the
4223 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4224
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4225<p>The shuffle mask operand is required to be a constant vector with either
4226 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4227
4228<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4229<p>The elements of the two input vectors are numbered from left to right across
4230 both of the vectors. The shuffle mask operand specifies, for each element of
4231 the result vector, which element of the two input vectors the result element
4232 gets. The element selector may be undef (meaning "don't care") and the
4233 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4234
4235<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4236<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4237 &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]4238 &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]4239 &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]4240 &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]4241 &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]4242 &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]4243 &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]4244 &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]4245</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4246
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4247</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4248
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4249</div>
4250
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4251<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4252<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4253 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4254</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4255
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4256<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4257
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4258<p>LLVM supports several instructions for working with
4259 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4260
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4261<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4262<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4263 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4264</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4265
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4266<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4267
4268<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4269<pre>
4270 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4271</pre>
4272
4273<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4274<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4275 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4276
4277<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4278<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4279 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4280 <a href="#t_array">array</a> type. The operands are constant indices to
4281 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4282 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4283 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4284 <ul>
4285 <li>Since the value being indexed is not a pointer, the first index is
4286 omitted and assumed to be zero.</li>
4287 <li>At least one index must be specified.</li>
4288 <li>Not only struct indices but also array indices must be in
4289 bounds.</li>
4290 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4291
4292<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4293<p>The result is the value at the position in the aggregate specified by the
4294 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4295
4296<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4297<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4298 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4299</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4300
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4301</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4302
4303<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4304<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4305 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4306</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4307
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4308<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4309
4310<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4311<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4312 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4313</pre>
4314
4315<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4316<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4317 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4318
4319<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4320<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4321 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4322 <a href="#t_array">array</a> type. The second operand is a first-class
4323 value to insert. The following operands are constant indices indicating
4324 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]4325 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4326 value to insert must have the same type as the value identified by the
4327 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4328
4329<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4330<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4331 that of <tt>val</tt> except that the value at the position specified by the
4332 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4333
4334<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4335<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4336 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4337 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4338 %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]4339</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4340
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4341</div>
4342
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4343</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4344
4345<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4346<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4347 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4348</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4349
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4350<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4351
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4352<p>A key design point of an SSA-based representation is how it represents
4353 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4354 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4355 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4356
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4357<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4358<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4359 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4360</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4361
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4362<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4364<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4365<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4366 &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]4367</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4368
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4369<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4370<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4371 currently executing function, to be automatically released when this function
4372 returns to its caller. The object is always allocated in the generic address
4373 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4374
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4375<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4376<p>The '<tt>alloca</tt>' instruction
4377 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4378 runtime stack, returning a pointer of the appropriate type to the program.
4379 If "NumElements" is specified, it is the number of elements allocated,
4380 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4381 specified, the value result of the allocation is guaranteed to be aligned to
4382 at least that boundary. If not specified, or if zero, the target can choose
4383 to align the allocation on any convenient boundary compatible with the
4384 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4385
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4386<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4387
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4388<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4389<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4390 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4391 memory is automatically released when the function returns. The
4392 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4393 variables that must have an address available. When the function returns
4394 (either with the <tt><a href="#i_ret">ret</a></tt>
4395 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4396 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4397
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4398<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4399<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4400 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4401 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4402 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4403 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4404</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4405
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4406</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4407
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4408<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4409<h4>
4410 <a name="i_load">'<tt>load</tt>' Instruction</a>
4411</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4412
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4413<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4414
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4415<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4416<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4417 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4418 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4419 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4420</pre>
4421
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4422<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4423<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4424
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4425<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4426<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4427 from which to load. The pointer must point to
4428 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4429 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4430 number or order of execution of this <tt>load</tt> with other <a
4431 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4432
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4433<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4434 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]4435 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4436 alignment for the target. It is the responsibility of the code emitter to
4437 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4438 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4439 produce less efficient code. An alignment of 1 is always safe.</p>
4440
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4441<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4442 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4443 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4444 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4445 and code generator that this load is not expected to be reused in the cache.
4446 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4447 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4448
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4449<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4450<p>The location of memory pointed to is loaded. If the value being loaded is of
4451 scalar type then the number of bytes read does not exceed the minimum number
4452 of bytes needed to hold all bits of the type. For example, loading an
4453 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4454 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4455 is undefined if the value was not originally written using a store of the
4456 same type.</p>
4457
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4458<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4459<pre>
4460 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4461 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4462 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4463</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4464
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4465</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4466
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4467<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4468<h4>
4469 <a name="i_store">'<tt>store</tt>' Instruction</a>
4470</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4471
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4472<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4473
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4474<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4475<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4476 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>
4477 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]4478</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4479
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4480<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4481<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4482
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4483<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4484<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4485 and an address at which to store it. The type of the
4486 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4487 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4488 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4489 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4490 order of execution of this <tt>store</tt> with other <a
4491 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4492
4493<p>The optional constant "align" argument specifies the alignment of the
4494 operation (that is, the alignment of the memory address). A value of 0 or an
4495 omitted "align" argument means that the operation has the preferential
4496 alignment for the target. It is the responsibility of the code emitter to
4497 ensure that the alignment information is correct. Overestimating the
4498 alignment results in an undefined behavior. Underestimating the alignment may
4499 produce less efficient code. An alignment of 1 is always safe.</p>
4500
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4501<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4502 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4503 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4504 instruction tells the optimizer and code generator that this load is
4505 not expected to be reused in the cache. The code generator may
4506 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4507 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4508
4509
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4510<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4511<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4512 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4513 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4514 does not exceed the minimum number of bytes needed to hold all bits of the
4515 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4516 writing a value of a type like <tt>i20</tt> with a size that is not an
4517 integral number of bytes, it is unspecified what happens to the extra bits
4518 that do not belong to the type, but they will typically be overwritten.</p>
4519
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4520<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4521<pre>
4522 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4523 store i32 3, i32* %ptr <i>; yields {void}</i>
4524 %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]4525</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4526
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4527</div>
4528
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4529<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4530<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4531 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4532</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4533
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4534<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4535
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4536<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4537<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4538 &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]4539 &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]4540</pre>
4541
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4542<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4543<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4544 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4545 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4546
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4547<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4548<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4549 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4550 elements of the aggregate object are indexed. The interpretation of each
4551 index is dependent on the type being indexed into. The first index always
4552 indexes the pointer value given as the first argument, the second index
4553 indexes a value of the type pointed to (not necessarily the value directly
4554 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4555 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4556 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4557 can never be pointers, since that would require loading the pointer before
4558 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4559
4560<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]4561 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4562 integer <b>constants</b> are allowed. When indexing into an array, pointer
4563 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]4564 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4565
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4566<p>For example, let's consider a C code fragment and how it gets compiled to
4567 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4568
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4569<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4570struct RT {
4571 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4572 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4573 char C;
4574};
4575struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4576 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4577 double Y;
4578 struct RT Z;
4579};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4580
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4581int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4582 return &amp;s[1].Z.B[5][13];
4583}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4584</pre>
4585
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4586<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4587
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4588<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4589%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4590%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4591
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4592define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4593entry:
4594 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4595 ret i32* %reg
4596}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4597</pre>
4598
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4599<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4600<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]4601 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4602 }</tt>' type, a structure. The second index indexes into the third element
4603 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4604 i8 }</tt>' type, another structure. The third index indexes into the second
4605 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4606 array. The two dimensions of the array are subscripted into, yielding an
4607 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4608 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4609
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4610<p>Note that it is perfectly legal to index partially through a structure,
4611 returning a pointer to an inner element. Because of this, the LLVM code for
4612 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4613
4614<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4615 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4616 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4617 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4618 %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]4619 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4620 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4621 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4622 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4623</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4624
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4625<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4626 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4627 base pointer is not an <i>in bounds</i> address of an allocated object,
4628 or if any of the addresses that would be formed by successive addition of
4629 the offsets implied by the indices to the base address with infinitely
4630 precise arithmetic are not an <i>in bounds</i> address of that allocated
4631 object. The <i>in bounds</i> addresses for an allocated object are all
4632 the addresses that point into the object, plus the address one byte past
4633 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4634
4635<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4636 the base address with silently-wrapping two's complement arithmetic, and
4637 the result value of the <tt>getelementptr</tt> may be outside the object
4638 pointed to by the base pointer. The result value may not necessarily be
4639 used to access memory though, even if it happens to point into allocated
4640 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4641 section for more information.</p>
4642
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4643<p>The getelementptr instruction is often confusing. For some more insight into
4644 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4645
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4646<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4647<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4648 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4649 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4650 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4651 %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]4652 <i>; yields i8*:eptr</i>
4653 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4654 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4655 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4656</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4657
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4658</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4659
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4660</div>
4661
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4662<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4663<h3>
4664 <a name="convertops">Conversion Operations</a>
4665</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4666
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4667<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4668
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4669<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4670 which all take a single operand and a type. They perform various bit
4671 conversions on the operand.</p>
4672
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4673<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4674<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4675 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4676</h4>
4677
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4678<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4679
4680<h5>Syntax:</h5>
4681<pre>
4682 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4683</pre>
4684
4685<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4686<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4687 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4688
4689<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4690<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4691 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4692 of the same number of integers.
4693 The bit size of the <tt>value</tt> must be larger than
4694 the bit size of the destination type, <tt>ty2</tt>.
4695 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4696
4697<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4698<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4699 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4700 source size must be larger than the destination size, <tt>trunc</tt> cannot
4701 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4702
4703<h5>Example:</h5>
4704<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4705 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4706 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4707 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4708 %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]4709</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4710
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4711</div>
4712
4713<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4714<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4715 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4716</h4>
4717
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4718<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4719
4720<h5>Syntax:</h5>
4721<pre>
4722 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4723</pre>
4724
4725<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4726<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4727 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4728
4729
4730<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4731<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4732 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4733 of the same number of integers.
4734 The bit size of the <tt>value</tt> must be smaller than
4735 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4736 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4737
4738<h5>Semantics:</h5>
4739<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]4740 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4741
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4742<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]4743
4744<h5>Example:</h5>
4745<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4746 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4747 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4748 %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]4749</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4750
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4751</div>
4752
4753<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4754<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4755 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4756</h4>
4757
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4758<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4759
4760<h5>Syntax:</h5>
4761<pre>
4762 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4763</pre>
4764
4765<h5>Overview:</h5>
4766<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4767
4768<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4769<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4770 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4771 of the same number of integers.
4772 The bit size of the <tt>value</tt> must be smaller than
4773 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4774 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4775
4776<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4777<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4778 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4779 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4780
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4781<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]4782
4783<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4784<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4785 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4786 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4787 %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]4788</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4789
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4790</div>
4791
4792<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4793<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4794 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4795</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4796
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4797<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4798
4799<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4800<pre>
4801 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4802</pre>
4803
4804<h5>Overview:</h5>
4805<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4806 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4807
4808<h5>Arguments:</h5>
4809<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4810 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4811 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]4812 <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]4813 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4814
4815<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4816<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4817 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4818 <a href="#t_floating">floating point</a> type. If the value cannot fit
4819 within the destination type, <tt>ty2</tt>, then the results are
4820 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4821
4822<h5>Example:</h5>
4823<pre>
4824 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4825 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4826</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4827
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4828</div>
4829
4830<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4831<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4832 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4833</h4>
4834
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4835<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4836
4837<h5>Syntax:</h5>
4838<pre>
4839 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4840</pre>
4841
4842<h5>Overview:</h5>
4843<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]4844 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4845
4846<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4847<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4848 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4849 a <a href="#t_floating">floating point</a> type to cast it to. The source
4850 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4851
4852<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4853<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4854 <a href="#t_floating">floating point</a> type to a larger
4855 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4856 used to make a <i>no-op cast</i> because it always changes bits. Use
4857 <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]4858
4859<h5>Example:</h5>
4860<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]4861 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4862 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4863</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4864
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4865</div>
4866
4867<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4868<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4869 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4870</h4>
4871
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4872<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4873
4874<h5>Syntax:</h5>
4875<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4876 &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]4877</pre>
4878
4879<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4880<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4881 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4882
4883<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4884<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4885 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4886 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4887 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4888 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4889
4890<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4891<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4892 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4893 towards zero) unsigned integer value. If the value cannot fit
4894 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4895
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4896<h5>Example:</h5>
4897<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4898 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4899 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4900 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4901</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4902
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4903</div>
4904
4905<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4906<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4907 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4908</h4>
4909
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4910<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4911
4912<h5>Syntax:</h5>
4913<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4914 &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]4915</pre>
4916
4917<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4918<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4919 <a href="#t_floating">floating point</a> <tt>value</tt> to
4920 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4921
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4922<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4923<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4924 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4925 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4926 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4927 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4928
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4929<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4930<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4931 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4932 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4933 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4934
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4935<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4936<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4937 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4938 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4939 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4940</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4941
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4942</div>
4943
4944<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4945<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4946 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4947</h4>
4948
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4949<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4950
4951<h5>Syntax:</h5>
4952<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4953 &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]4954</pre>
4955
4956<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4957<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4958 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4959
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4960<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4961<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]4962 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4963 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4964 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4965 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4966
4967<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4968<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4969 integer quantity and converts it to the corresponding floating point
4970 value. If the value cannot fit in the floating point value, the results are
4971 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4972
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4973<h5>Example:</h5>
4974<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4975 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4976 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4977</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4978
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4979</div>
4980
4981<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4982<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4983 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4984</h4>
4985
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4986<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4987
4988<h5>Syntax:</h5>
4989<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4990 &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]4991</pre>
4992
4993<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4994<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4995 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4996
4997<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4998<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]4999 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5000 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5001 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5002 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5003
5004<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5005<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5006 quantity and converts it to the corresponding floating point value. If the
5007 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5008
5009<h5>Example:</h5>
5010<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5011 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5012 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5013</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5014
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5015</div>
5016
5017<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5018<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5019 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5020</h4>
5021
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5022<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5023
5024<h5>Syntax:</h5>
5025<pre>
5026 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5027</pre>
5028
5029<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5030<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5031 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5032
5033<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5034<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5035 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5036 <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]5037
5038<h5>Semantics:</h5>
5039<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5040 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5041 truncating or zero extending that value to the size of the integer type. If
5042 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5043 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5044 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5045 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5046
5047<h5>Example:</h5>
5048<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5049 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5050 %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]5051</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5052
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5053</div>
5054
5055<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5056<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5057 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5058</h4>
5059
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5060<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5061
5062<h5>Syntax:</h5>
5063<pre>
5064 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5065</pre>
5066
5067<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5068<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5069 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5070
5071<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5072<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5073 value to cast, and a type to cast it to, which must be a
5074 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5075
5076<h5>Semantics:</h5>
5077<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5078 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5079 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5080 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5081 than the size of a pointer then a zero extension is done. If they are the
5082 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5083
5084<h5>Example:</h5>
5085<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5086 %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]5087 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5088 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5089</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5090
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5091</div>
5092
5093<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5094<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5095 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5096</h4>
5097
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5098<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5099
5100<h5>Syntax:</h5>
5101<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5102 &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]5103</pre>
5104
5105<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5106<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5107 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5108
5109<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5110<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5111 non-aggregate first class value, and a type to cast it to, which must also be
5112 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5113 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5114 identical. If the source type is a pointer, the destination type must also be
5115 a pointer. This instruction supports bitwise conversion of vectors to
5116 integers and to vectors of other types (as long as they have the same
5117 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5118
5119<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5120<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5121 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5122 this conversion. The conversion is done as if the <tt>value</tt> had been
5123 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5124 be converted to other pointer types with this instruction. To convert
5125 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5126 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5127
5128<h5>Example:</h5>
5129<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5130 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5131 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5132 %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]5133</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5134
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5135</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5136
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5137</div>
5138
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5139<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5140<h3>
5141 <a name="otherops">Other Operations</a>
5142</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5143
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5144<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5145
5146<p>The instructions in this category are the "miscellaneous" instructions, which
5147 defy better classification.</p>
5148
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5149<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5150<h4>
5151 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5152</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5153
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5154<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5155
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5156<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5157<pre>
5158 &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]5159</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5160
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5161<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5162<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5163 boolean values based on comparison of its two integer, integer vector, or
5164 pointer operands.</p>
5165
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5166<h5>Arguments:</h5>
5167<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5168 the condition code indicating the kind of comparison to perform. It is not a
5169 value, just a keyword. The possible condition code are:</p>
5170
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5171<ol>
5172 <li><tt>eq</tt>: equal</li>
5173 <li><tt>ne</tt>: not equal </li>
5174 <li><tt>ugt</tt>: unsigned greater than</li>
5175 <li><tt>uge</tt>: unsigned greater or equal</li>
5176 <li><tt>ult</tt>: unsigned less than</li>
5177 <li><tt>ule</tt>: unsigned less or equal</li>
5178 <li><tt>sgt</tt>: signed greater than</li>
5179 <li><tt>sge</tt>: signed greater or equal</li>
5180 <li><tt>slt</tt>: signed less than</li>
5181 <li><tt>sle</tt>: signed less or equal</li>
5182</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5183
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5184<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5185 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5186 typed. They must also be identical types.</p>
5187
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5188<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5189<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5190 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5191 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]5192 result, as follows:</p>
5193
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5194<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5195 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5196 <tt>false</tt> otherwise. No sign interpretation is necessary or
5197 performed.</li>
5198
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5199 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5200 <tt>false</tt> otherwise. No sign interpretation is necessary or
5201 performed.</li>
5202
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5203 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5204 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5205
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5206 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5207 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5208 to <tt>op2</tt>.</li>
5209
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5210 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5211 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5212
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5213 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5214 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5215
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5216 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5217 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5218
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5219 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5220 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5221 to <tt>op2</tt>.</li>
5222
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5223 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5224 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5225
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5226 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5227 <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]5228</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5229
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5230<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5231 values are compared as if they were integers.</p>
5232
5233<p>If the operands are integer vectors, then they are compared element by
5234 element. The result is an <tt>i1</tt> vector with the same number of elements
5235 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5236
5237<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5238<pre>
5239 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5240 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5241 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5242 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5243 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5244 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5245</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5246
5247<p>Note that the code generator does not yet support vector types with
5248 the <tt>icmp</tt> instruction.</p>
5249
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5250</div>
5251
5252<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5253<h4>
5254 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5255</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5256
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5257<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5258
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5259<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5260<pre>
5261 &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]5262</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5263
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5264<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5265<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5266 values based on comparison of its operands.</p>
5267
5268<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]5269(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5270
5271<p>If the operands are floating point vectors, then the result type is a vector
5272 of boolean with the same number of elements as the operands being
5273 compared.</p>
5274
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5275<h5>Arguments:</h5>
5276<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5277 the condition code indicating the kind of comparison to perform. It is not a
5278 value, just a keyword. The possible condition code are:</p>
5279
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5280<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5281 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5282 <li><tt>oeq</tt>: ordered and equal</li>
5283 <li><tt>ogt</tt>: ordered and greater than </li>
5284 <li><tt>oge</tt>: ordered and greater than or equal</li>
5285 <li><tt>olt</tt>: ordered and less than </li>
5286 <li><tt>ole</tt>: ordered and less than or equal</li>
5287 <li><tt>one</tt>: ordered and not equal</li>
5288 <li><tt>ord</tt>: ordered (no nans)</li>
5289 <li><tt>ueq</tt>: unordered or equal</li>
5290 <li><tt>ugt</tt>: unordered or greater than </li>
5291 <li><tt>uge</tt>: unordered or greater than or equal</li>
5292 <li><tt>ult</tt>: unordered or less than </li>
5293 <li><tt>ule</tt>: unordered or less than or equal</li>
5294 <li><tt>une</tt>: unordered or not equal</li>
5295 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5296 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5297</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5298
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5299<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5300 <i>unordered</i> means that either operand may be a QNAN.</p>
5301
5302<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5303 a <a href="#t_floating">floating point</a> type or
5304 a <a href="#t_vector">vector</a> of floating point type. They must have
5305 identical types.</p>
5306
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5307<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5308<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5309 according to the condition code given as <tt>cond</tt>. If the operands are
5310 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5311 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5312 follows:</p>
5313
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5314<ol>
5315 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5316
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5317 <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]5318 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5319
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5320 <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]5321 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5322
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5323 <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]5324 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5325
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5326 <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]5327 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5328
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5329 <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]5330 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5331
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5332 <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]5333 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5334
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5335 <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]5336
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5337 <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]5338 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5339
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5340 <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]5341 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5342
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5343 <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]5344 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5345
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5346 <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]5347 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5348
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5349 <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]5350 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5351
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5352 <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]5353 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5354
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5355 <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]5356
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5357 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5358</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5359
5360<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5361<pre>
5362 &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]5363 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5364 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5365 &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]5366</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5367
5368<p>Note that the code generator does not yet support vector types with
5369 the <tt>fcmp</tt> instruction.</p>
5370
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5371</div>
5372
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5373<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5374<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5375 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5376</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5377
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5378<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5379
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5380<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5381<pre>
5382 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5383</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5384
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5385<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5386<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5387 SSA graph representing the function.</p>
5388
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5389<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5390<p>The type of the incoming values is specified with the first type field. After
5391 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5392 one pair for each predecessor basic block of the current block. Only values
5393 of <a href="#t_firstclass">first class</a> type may be used as the value
5394 arguments to the PHI node. Only labels may be used as the label
5395 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5396
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5397<p>There must be no non-phi instructions between the start of a basic block and
5398 the PHI instructions: i.e. PHI instructions must be first in a basic
5399 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5400
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5401<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5402 occur on the edge from the corresponding predecessor block to the current
5403 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5404 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5405
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5406<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5407<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5408 specified by the pair corresponding to the predecessor basic block that
5409 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5410
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5411<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5412<pre>
5413Loop: ; Infinite loop that counts from 0 on up...
5414 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5415 %nextindvar = add i32 %indvar, 1
5416 br label %Loop
5417</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5418
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5419</div>
5420
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5421<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5422<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5423 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5424</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5425
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5426<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5427
5428<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5429<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5430 &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>
5431
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5432 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5433</pre>
5434
5435<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5436<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5437 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5438
5439
5440<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5441<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5442 values indicating the condition, and two values of the
5443 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5444 vectors and the condition is a scalar, then entire vectors are selected, not
5445 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5446
5447<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5448<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5449 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5450
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5451<p>If the condition is a vector of i1, then the value arguments must be vectors
5452 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5453
5454<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5455<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5456 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5457</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5458
5459<p>Note that the code generator does not yet support conditions
5460 with vector type.</p>
5461
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5462</div>
5463
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5464<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5465<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5466 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5467</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5468
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5469<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5470
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5471<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5472<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5473 &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]5474</pre>
5475
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5476<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5477<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5478
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5479<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5480<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5481
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5482<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5483 <li>The optional "tail" marker indicates that the callee function does not
5484 access any allocas or varargs in the caller. Note that calls may be
5485 marked "tail" even if they do not occur before
5486 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5487 present, the function call is eligible for tail call optimization,
5488 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5489 optimized into a jump</a>. The code generator may optimize calls marked
5490 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5491 sibling call optimization</a> when the caller and callee have
5492 matching signatures, or 2) forced tail call optimization when the
5493 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5494 <ul>
5495 <li>Caller and callee both have the calling
5496 convention <tt>fastcc</tt>.</li>
5497 <li>The call is in tail position (ret immediately follows call and ret
5498 uses value of call or is void).</li>
5499 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5500 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5501 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5502 constraints are met.</a></li>
5503 </ul>
5504 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5505
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5506 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5507 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5508 defaults to using C calling conventions. The calling convention of the
5509 call must match the calling convention of the target function, or else the
5510 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5511
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5512 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5513 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5514 '<tt>inreg</tt>' attributes are valid here.</li>
5515
5516 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5517 type of the return value. Functions that return no value are marked
5518 <tt><a href="#t_void">void</a></tt>.</li>
5519
5520 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5521 being invoked. The argument types must match the types implied by this
5522 signature. This type can be omitted if the function is not varargs and if
5523 the function type does not return a pointer to a function.</li>
5524
5525 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5526 be invoked. In most cases, this is a direct function invocation, but
5527 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5528 to function value.</li>
5529
5530 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5531 signature argument types and parameter attributes. All arguments must be
5532 of <a href="#t_firstclass">first class</a> type. If the function
5533 signature indicates the function accepts a variable number of arguments,
5534 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5535
5536 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5537 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5538 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5539</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5540
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5541<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5542<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5543 a specified function, with its incoming arguments bound to the specified
5544 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5545 function, control flow continues with the instruction after the function
5546 call, and the return value of the function is bound to the result
5547 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5548
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5549<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5550<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5551 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5552 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5553 %X = tail call i32 @foo() <i>; yields i32</i>
5554 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5555 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5556
5557 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5558 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5559 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5560 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5561 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5562 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5563</pre>
5564
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5565<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5566standard C99 library as being the C99 library functions, and may perform
5567optimizations or generate code for them under that assumption. This is
5568something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5569freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5570
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5571</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5572
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5573<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5574<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5575 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5576</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5577
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5578<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5579
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5580<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5581<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5582 &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]5583</pre>
5584
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5585<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5586<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5587 the "variable argument" area of a function call. It is used to implement the
5588 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5589
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5590<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5591<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5592 argument. It returns a value of the specified argument type and increments
5593 the <tt>va_list</tt> to point to the next argument. The actual type
5594 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5595
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5596<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5597<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5598 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5599 to the next argument. For more information, see the variable argument
5600 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5601
5602<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]5603 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5604 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5605
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5606<p><tt>va_arg</tt> is an LLVM instruction instead of
5607 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5608 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5609
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5610<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5611<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5612
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5613<p>Note that the code generator does not yet fully support va_arg on many
5614 targets. Also, it does not currently support va_arg with aggregate types on
5615 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5616
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5617</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5618
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5619</div>
5620
5621</div>
5622
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5623<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5624<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5625<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5626
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5627<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5628
5629<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5630 well known names and semantics and are required to follow certain
5631 restrictions. Overall, these intrinsics represent an extension mechanism for
5632 the LLVM language that does not require changing all of the transformations
5633 in LLVM when adding to the language (or the bitcode reader/writer, the
5634 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5635
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5636<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5637 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5638 begin with this prefix. Intrinsic functions must always be external
5639 functions: you cannot define the body of intrinsic functions. Intrinsic
5640 functions may only be used in call or invoke instructions: it is illegal to
5641 take the address of an intrinsic function. Additionally, because intrinsic
5642 functions are part of the LLVM language, it is required if any are added that
5643 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5644
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5645<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5646 family of functions that perform the same operation but on different data
5647 types. Because LLVM can represent over 8 million different integer types,
5648 overloading is used commonly to allow an intrinsic function to operate on any
5649 integer type. One or more of the argument types or the result type can be
5650 overloaded to accept any integer type. Argument types may also be defined as
5651 exactly matching a previous argument's type or the result type. This allows
5652 an intrinsic function which accepts multiple arguments, but needs all of them
5653 to be of the same type, to only be overloaded with respect to a single
5654 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5655
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5656<p>Overloaded intrinsics will have the names of its overloaded argument types
5657 encoded into its function name, each preceded by a period. Only those types
5658 which are overloaded result in a name suffix. Arguments whose type is matched
5659 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5660 can take an integer of any width and returns an integer of exactly the same
5661 integer width. This leads to a family of functions such as
5662 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5663 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5664 suffix is required. Because the argument's type is matched against the return
5665 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5666
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5667<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5668 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5669
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5670<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5671<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5672 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5673</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5674
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5675<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5676
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5677<p>Variable argument support is defined in LLVM with
5678 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5679 intrinsic functions. These functions are related to the similarly named
5680 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5681
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5682<p>All of these functions operate on arguments that use a target-specific value
5683 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5684 not define what this type is, so all transformations should be prepared to
5685 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5686
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5687<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]5688 instruction and the variable argument handling intrinsic functions are
5689 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5690
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5691<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5692define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5693 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5694 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5695 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5696 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5697
5698 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5699 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5700
5701 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5702 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5703 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5704 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5705 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5706
5707 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5708 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5709 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5710}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5711
5712declare void @llvm.va_start(i8*)
5713declare void @llvm.va_copy(i8*, i8*)
5714declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5715</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5716
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5717<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5718<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5719 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5720</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5721
5722
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5723<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5724
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5725<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5726<pre>
5727 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5728</pre>
5729
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5730<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5731<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5732 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]5733
5734<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5735<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]5736
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5737<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5738<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]5739 macro available in C. In a target-dependent way, it initializes
5740 the <tt>va_list</tt> element to which the argument points, so that the next
5741 call to <tt>va_arg</tt> will produce the first variable argument passed to
5742 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5743 need to know the last argument of the function as the compiler can figure
5744 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5745
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5746</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5747
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5748<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5749<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5750 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5751</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5752
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5753<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5754
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5755<h5>Syntax:</h5>
5756<pre>
5757 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5758</pre>
5759
5760<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5761<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5762 which has been initialized previously
5763 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5764 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5765
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5766<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5767<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]5768
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5769<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5770<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]5771 macro available in C. In a target-dependent way, it destroys
5772 the <tt>va_list</tt> element to which the argument points. Calls
5773 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5774 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5775 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5776
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5777</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5778
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5779<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5780<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5781 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5782</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5783
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5784<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5785
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5786<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5787<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5788 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5789</pre>
5790
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5791<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5792<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5793 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5794
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5795<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5796<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]5797 The second argument is a pointer to a <tt>va_list</tt> element to copy
5798 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5799
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5800<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5801<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]5802 macro available in C. In a target-dependent way, it copies the
5803 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5804 element. This intrinsic is necessary because
5805 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5806 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5807
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5808</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5809
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5810</div>
5811
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5812<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5813<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5814 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5815</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5816
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5817<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5818
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5819<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5820Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5821intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5822roots on the stack</a>, as well as garbage collector implementations that
5823require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5824barriers. Front-ends for type-safe garbage collected languages should generate
5825these intrinsics to make use of the LLVM garbage collectors. For more details,
5826see <a href="GarbageCollection.html">Accurate Garbage Collection with
5827LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5828
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5829<p>The garbage collection intrinsics only operate on objects in the generic
5830 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5831
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5832<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5833<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5834 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5835</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5836
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5837<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5838
5839<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5840<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5841 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5842</pre>
5843
5844<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5845<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]5846 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5847
5848<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5849<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5850 root pointer. The second pointer (which must be either a constant or a
5851 global value address) contains the meta-data to be associated with the
5852 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5853
5854<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5855<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]5856 location. At compile-time, the code generator generates information to allow
5857 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5858 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5859 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5860
5861</div>
5862
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5863<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5864<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5865 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5866</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5867
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5868<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5869
5870<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5871<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5872 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5873</pre>
5874
5875<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5876<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5877 locations, allowing garbage collector implementations that require read
5878 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5879
5880<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5881<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]5882 allocated from the garbage collector. The first object is a pointer to the
5883 start of the referenced object, if needed by the language runtime (otherwise
5884 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5885
5886<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5887<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5888 instruction, but may be replaced with substantially more complex code by the
5889 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5890 may only be used in a function which <a href="#gc">specifies a GC
5891 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5892
5893</div>
5894
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5895<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5896<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5897 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5898</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5899
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5900<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5901
5902<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5903<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5904 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5905</pre>
5906
5907<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5908<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5909 locations, allowing garbage collector implementations that require write
5910 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5911
5912<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5913<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]5914 object to store it to, and the third is the address of the field of Obj to
5915 store to. If the runtime does not require a pointer to the object, Obj may
5916 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5917
5918<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5919<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5920 instruction, but may be replaced with substantially more complex code by the
5921 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5922 may only be used in a function which <a href="#gc">specifies a GC
5923 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5924
5925</div>
5926
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5927</div>
5928
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5929<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5930<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5931 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5932</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5933
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5934<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5935
5936<p>These intrinsics are provided by LLVM to expose special features that may
5937 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5938
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5939<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5940<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5941 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5942</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5943
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5944<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5945
5946<h5>Syntax:</h5>
5947<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5948 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5949</pre>
5950
5951<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5952<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5953 target-specific value indicating the return address of the current function
5954 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5955
5956<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5957<p>The argument to this intrinsic indicates which function to return the address
5958 for. Zero indicates the calling function, one indicates its caller, etc.
5959 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5960
5961<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5962<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5963 indicating the return address of the specified call frame, or zero if it
5964 cannot be identified. The value returned by this intrinsic is likely to be
5965 incorrect or 0 for arguments other than zero, so it should only be used for
5966 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5967
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5968<p>Note that calling this intrinsic does not prevent function inlining or other
5969 aggressive transformations, so the value returned may not be that of the
5970 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5971
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5972</div>
5973
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5974<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5975<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5976 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5977</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5978
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5979<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5980
5981<h5>Syntax:</h5>
5982<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5983 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5984</pre>
5985
5986<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5987<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5988 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5989
5990<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5991<p>The argument to this intrinsic indicates which function to return the frame
5992 pointer for. Zero indicates the calling function, one indicates its caller,
5993 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5994
5995<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5996<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5997 indicating the frame address of the specified call frame, or zero if it
5998 cannot be identified. The value returned by this intrinsic is likely to be
5999 incorrect or 0 for arguments other than zero, so it should only be used for
6000 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6001
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6002<p>Note that calling this intrinsic does not prevent function inlining or other
6003 aggressive transformations, so the value returned may not be that of the
6004 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6005
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6006</div>
6007
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6008<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6009<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6010 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6011</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6012
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6013<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6014
6015<h5>Syntax:</h5>
6016<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6017 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6018</pre>
6019
6020<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6021<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6022 of the function stack, for use
6023 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6024 useful for implementing language features like scoped automatic variable
6025 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6026
6027<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6028<p>This intrinsic returns a opaque pointer value that can be passed
6029 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6030 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6031 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6032 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6033 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6034 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6035
6036</div>
6037
6038<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6039<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6040 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6041</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6042
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6043<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6044
6045<h5>Syntax:</h5>
6046<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6047 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6048</pre>
6049
6050<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6051<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6052 the function stack to the state it was in when the
6053 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6054 executed. This is useful for implementing language features like scoped
6055 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6056
6057<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6058<p>See the description
6059 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6060
6061</div>
6062
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6063<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6064<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6065 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6066</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6067
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6068<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6069
6070<h5>Syntax:</h5>
6071<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6072 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]6073</pre>
6074
6075<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6076<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6077 insert a prefetch instruction if supported; otherwise, it is a noop.
6078 Prefetches have no effect on the behavior of the program but can change its
6079 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6080
6081<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6082<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6083 specifier determining if the fetch should be for a read (0) or write (1),
6084 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6085 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6086 specifies whether the prefetch is performed on the data (1) or instruction (0)
6087 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6088 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6089
6090<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6091<p>This intrinsic does not modify the behavior of the program. In particular,
6092 prefetches cannot trap and do not produce a value. On targets that support
6093 this intrinsic, the prefetch can provide hints to the processor cache for
6094 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6095
6096</div>
6097
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6098<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6099<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6100 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6101</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6102
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6103<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6104
6105<h5>Syntax:</h5>
6106<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6107 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6108</pre>
6109
6110<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6111<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6112 Counter (PC) in a region of code to simulators and other tools. The method
6113 is target specific, but it is expected that the marker will use exported
6114 symbols to transmit the PC of the marker. The marker makes no guarantees
6115 that it will remain with any specific instruction after optimizations. It is
6116 possible that the presence of a marker will inhibit optimizations. The
6117 intended use is to be inserted after optimizations to allow correlations of
6118 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6119
6120<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6121<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6122
6123<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6124<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6125 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6126
6127</div>
6128
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6129<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6130<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6131 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6132</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6133
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6134<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6135
6136<h5>Syntax:</h5>
6137<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6138 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6139</pre>
6140
6141<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6142<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6143 counter register (or similar low latency, high accuracy clocks) on those
6144 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6145 should map to RPCC. As the backing counters overflow quickly (on the order
6146 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6147
6148<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6149<p>When directly supported, reading the cycle counter should not modify any
6150 memory. Implementations are allowed to either return a application specific
6151 value or a system wide value. On backends without support, this is lowered
6152 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6153
6154</div>
6155
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6156</div>
6157
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6158<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6159<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6160 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6161</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6162
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6163<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6164
6165<p>LLVM provides intrinsics for a few important standard C library functions.
6166 These intrinsics allow source-language front-ends to pass information about
6167 the alignment of the pointer arguments to the code generator, providing
6168 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6169
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6170<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6171<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6172 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6173</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6174
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6175<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6176
6177<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6178<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]6179 integer bit width and for different address spaces. Not all targets support
6180 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6181
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6182<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6183 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]6184 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6185 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]6186 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6187</pre>
6188
6189<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6190<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6191 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6192
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6193<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6194 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6195 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6196
6197<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6198
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6199<p>The first argument is a pointer to the destination, the second is a pointer
6200 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6201 number of bytes to copy, the fourth argument is the alignment of the
6202 source and destination locations, and the fifth is a boolean indicating a
6203 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6204
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6205<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]6206 then the caller guarantees that both the source and destination pointers are
6207 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6208
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6209<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6210 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6211 The detailed access behavior is not very cleanly specified and it is unwise
6212 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6213
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6214<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6215
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6216<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6217 source location to the destination location, which are not allowed to
6218 overlap. It copies "len" bytes of memory over. If the argument is known to
6219 be aligned to some boundary, this can be specified as the fourth argument,
6220 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6221
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6222</div>
6223
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6224<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6225<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6226 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6227</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6228
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6229<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6230
6231<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6232<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]6233 width and for different address space. Not all targets support all bit
6234 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6235
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6236<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6237 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]6238 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6239 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]6240 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6241</pre>
6242
6243<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6244<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6245 source location to the destination location. It is similar to the
6246 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6247 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6248
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6249<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6250 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6251 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6252
6253<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6254
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6255<p>The first argument is a pointer to the destination, the second is a pointer
6256 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6257 number of bytes to copy, the fourth argument is the alignment of the
6258 source and destination locations, and the fifth is a boolean indicating a
6259 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6260
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6261<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]6262 then the caller guarantees that the source and destination pointers are
6263 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6264
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6265<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6266 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6267 The detailed access behavior is not very cleanly specified and it is unwise
6268 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6269
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6270<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6271
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6272<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6273 source location to the destination location, which may overlap. It copies
6274 "len" bytes of memory over. If the argument is known to be aligned to some
6275 boundary, this can be specified as the fourth argument, otherwise it should
6276 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6277
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6278</div>
6279
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6280<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6281<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6282 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6283</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6284
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6285<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6286
6287<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6288<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]6289 width and for different address spaces. However, not all targets support all
6290 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6291
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6292<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6293 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6294 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6295 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6296 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6297</pre>
6298
6299<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6300<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6301 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6302
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6303<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6304 intrinsic does not return a value and takes extra alignment/volatile
6305 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6306
6307<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6308<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]6309 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6310 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6311 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6312
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6313<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]6314 then the caller guarantees that the destination pointer is aligned to that
6315 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6316
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6317<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6318 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6319 The detailed access behavior is not very cleanly specified and it is unwise
6320 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6321
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6322<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6323<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6324 at the destination location. If the argument is known to be aligned to some
6325 boundary, this can be specified as the fourth argument, otherwise it should
6326 be set to 0 or 1.</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 Lattner3b4f4372004-06-11 02:28:03 +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_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6333</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6334
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6335<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6336
6337<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6338<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6339 floating point or vector of floating point type. Not all targets support all
6340 types however.</p>
6341
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6342<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6343 declare float @llvm.sqrt.f32(float %Val)
6344 declare double @llvm.sqrt.f64(double %Val)
6345 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6346 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6347 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6348</pre>
6349
6350<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6351<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6352 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6353 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6354 behavior for negative numbers other than -0.0 (which allows for better
6355 optimization, because there is no need to worry about errno being
6356 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]6357
6358<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6359<p>The argument and return value are floating point numbers of the same
6360 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6361
6362<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6363<p>This function returns the sqrt of the specified operand if it is a
6364 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6365
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6366</div>
6367
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6368<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6369<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6370 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6371</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6372
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6373<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6374
6375<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6376<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6377 floating point or vector of floating point type. Not all targets support all
6378 types however.</p>
6379
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6380<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6381 declare float @llvm.powi.f32(float %Val, i32 %power)
6382 declare double @llvm.powi.f64(double %Val, i32 %power)
6383 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6384 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6385 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6386</pre>
6387
6388<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6389<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6390 specified (positive or negative) power. The order of evaluation of
6391 multiplications is not defined. When a vector of floating point type is
6392 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6393
6394<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6395<p>The second argument is an integer power, and the first is a value to raise to
6396 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6397
6398<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6399<p>This function returns the first value raised to the second power with an
6400 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6401
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6402</div>
6403
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6404<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6405<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6406 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6407</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6408
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6409<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6410
6411<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6412<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6413 floating point or vector of floating point type. Not all targets support all
6414 types however.</p>
6415
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6416<pre>
6417 declare float @llvm.sin.f32(float %Val)
6418 declare double @llvm.sin.f64(double %Val)
6419 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6420 declare fp128 @llvm.sin.f128(fp128 %Val)
6421 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6422</pre>
6423
6424<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6425<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6426
6427<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6428<p>The argument and return value are floating point numbers of the same
6429 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6430
6431<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6432<p>This function returns the sine of the specified operand, returning the same
6433 values as the libm <tt>sin</tt> functions would, and handles error conditions
6434 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6435
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6436</div>
6437
6438<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6439<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6440 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6441</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6442
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6443<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6444
6445<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6446<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6447 floating point or vector of floating point type. Not all targets support all
6448 types however.</p>
6449
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6450<pre>
6451 declare float @llvm.cos.f32(float %Val)
6452 declare double @llvm.cos.f64(double %Val)
6453 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6454 declare fp128 @llvm.cos.f128(fp128 %Val)
6455 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6456</pre>
6457
6458<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6459<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6460
6461<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6462<p>The argument and return value are floating point numbers of the same
6463 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6464
6465<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6466<p>This function returns the cosine of the specified operand, returning the same
6467 values as the libm <tt>cos</tt> functions would, and handles error conditions
6468 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6469
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6470</div>
6471
6472<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6473<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6474 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6475</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6476
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6477<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6478
6479<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6480<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6481 floating point or vector of floating point type. Not all targets support all
6482 types however.</p>
6483
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6484<pre>
6485 declare float @llvm.pow.f32(float %Val, float %Power)
6486 declare double @llvm.pow.f64(double %Val, double %Power)
6487 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6488 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6489 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6490</pre>
6491
6492<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6493<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6494 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6495
6496<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6497<p>The second argument is a floating point power, and the first is a value to
6498 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6499
6500<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6501<p>This function returns the first value raised to the second power, returning
6502 the same values as the libm <tt>pow</tt> functions would, and handles error
6503 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6504
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6505</div>
6506
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6507</div>
6508
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6509<!-- _______________________________________________________________________ -->
6510<h4>
6511 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6512</h4>
6513
6514<div>
6515
6516<h5>Syntax:</h5>
6517<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6518 floating point or vector of floating point type. Not all targets support all
6519 types however.</p>
6520
6521<pre>
6522 declare float @llvm.exp.f32(float %Val)
6523 declare double @llvm.exp.f64(double %Val)
6524 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6525 declare fp128 @llvm.exp.f128(fp128 %Val)
6526 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6527</pre>
6528
6529<h5>Overview:</h5>
6530<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6531
6532<h5>Arguments:</h5>
6533<p>The argument and return value are floating point numbers of the same
6534 type.</p>
6535
6536<h5>Semantics:</h5>
6537<p>This function returns the same values as the libm <tt>exp</tt> functions
6538 would, and handles error conditions in the same way.</p>
6539
6540</div>
6541
6542<!-- _______________________________________________________________________ -->
6543<h4>
6544 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6545</h4>
6546
6547<div>
6548
6549<h5>Syntax:</h5>
6550<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6551 floating point or vector of floating point type. Not all targets support all
6552 types however.</p>
6553
6554<pre>
6555 declare float @llvm.log.f32(float %Val)
6556 declare double @llvm.log.f64(double %Val)
6557 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6558 declare fp128 @llvm.log.f128(fp128 %Val)
6559 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6560</pre>
6561
6562<h5>Overview:</h5>
6563<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6564
6565<h5>Arguments:</h5>
6566<p>The argument and return value are floating point numbers of the same
6567 type.</p>
6568
6569<h5>Semantics:</h5>
6570<p>This function returns the same values as the libm <tt>log</tt> functions
6571 would, and handles error conditions in the same way.</p>
6572
6573</div>
6574
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6575<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6576<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6577 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6578</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6579
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6580<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6581
6582<p>LLVM provides intrinsics for a few important bit manipulation operations.
6583 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6584
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6585<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6586<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6587 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6588</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6589
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6590<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6591
6592<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6593<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6594 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6595
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6596<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6597 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6598 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6599 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6600</pre>
6601
6602<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6603<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6604 values with an even number of bytes (positive multiple of 16 bits). These
6605 are useful for performing operations on data that is not in the target's
6606 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6607
6608<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6609<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6610 and low byte of the input i16 swapped. Similarly,
6611 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6612 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6613 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6614 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6615 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6616 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6617
6618</div>
6619
6620<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6621<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6622 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6623</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6624
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6625<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6626
6627<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6628<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]6629 width, or on any vector with integer elements. Not all targets support all
6630 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6631
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6632<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6633 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6634 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6635 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6636 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6637 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6638 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]6639</pre>
6640
6641<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6642<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6643 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6644
6645<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6646<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]6647 integer type, or a vector with integer elements.
6648 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6649
6650<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6651<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6652 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6653
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6654</div>
6655
6656<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6657<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6658 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6659</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6660
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6661<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6662
6663<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6664<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]6665 integer bit width, or any vector whose elements are integers. Not all
6666 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6667
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6668<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6669 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6670 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6671 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6672 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6673 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6674 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]6675</pre>
6676
6677<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6678<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6679 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6680
6681<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6682<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]6683 integer type, or any vector type with integer element type.
6684 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6685
6686<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6687<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6688 zeros in a variable, or within each element of the vector if the operation
6689 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]6690 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6691
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6692</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6693
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6694<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6695<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6696 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6697</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6698
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6699<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6700
6701<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6702<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]6703 integer bit width, or any vector of integer elements. Not all targets
6704 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6705
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6706<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6707 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6708 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6709 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6710 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6711 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6712 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]6713</pre>
6714
6715<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6716<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6717 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6718
6719<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6720<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]6721 integer type, or a vectory with integer element type.. The return type
6722 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6723
6724<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6725<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6726 zeros in a variable, or within each element of a vector.
6727 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6728 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6729
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6730</div>
6731
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6732</div>
6733
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6734<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6735<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6736 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6737</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6738
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6739<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6740
6741<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6742
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6743<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6744<h4>
6745 <a name="int_sadd_overflow">
6746 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6747 </a>
6748</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6749
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6750<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6751
6752<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6753<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]6754 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6755
6756<pre>
6757 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6758 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6759 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6760</pre>
6761
6762<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6763<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6764 a signed addition of the two arguments, and indicate whether an overflow
6765 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6766
6767<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6768<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]6769 be of integer types of any bit width, but they must have the same bit
6770 width. The second element of the result structure must be of
6771 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6772 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6773
6774<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6775<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776 a signed addition of the two variables. They return a structure &mdash; the
6777 first element of which is the signed summation, and the second element of
6778 which is a bit specifying if the signed summation resulted in an
6779 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6780
6781<h5>Examples:</h5>
6782<pre>
6783 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6784 %sum = extractvalue {i32, i1} %res, 0
6785 %obit = extractvalue {i32, i1} %res, 1
6786 br i1 %obit, label %overflow, label %normal
6787</pre>
6788
6789</div>
6790
6791<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6792<h4>
6793 <a name="int_uadd_overflow">
6794 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6795 </a>
6796</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6797
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6798<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6799
6800<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6801<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]6802 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6803
6804<pre>
6805 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6806 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6807 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6808</pre>
6809
6810<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6811<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6812 an unsigned addition of the two arguments, and indicate whether a carry
6813 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6814
6815<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6816<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]6817 be of integer types of any bit width, but they must have the same bit
6818 width. The second element of the result structure must be of
6819 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6820 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6821
6822<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6823<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6824 an unsigned addition of the two arguments. They return a structure &mdash;
6825 the first element of which is the sum, and the second element of which is a
6826 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6827
6828<h5>Examples:</h5>
6829<pre>
6830 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6831 %sum = extractvalue {i32, i1} %res, 0
6832 %obit = extractvalue {i32, i1} %res, 1
6833 br i1 %obit, label %carry, label %normal
6834</pre>
6835
6836</div>
6837
6838<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6839<h4>
6840 <a name="int_ssub_overflow">
6841 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6842 </a>
6843</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6844
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6845<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6846
6847<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6848<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]6849 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6850
6851<pre>
6852 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6853 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6854 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6855</pre>
6856
6857<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6858<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6859 a signed subtraction of the two arguments, and indicate whether an overflow
6860 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6861
6862<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6863<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]6864 be of integer types of any bit width, but they must have the same bit
6865 width. The second element of the result structure must be of
6866 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6867 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6868
6869<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6870<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6871 a signed subtraction of the two arguments. They return a structure &mdash;
6872 the first element of which is the subtraction, and the second element of
6873 which is a bit specifying if the signed subtraction resulted in an
6874 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6875
6876<h5>Examples:</h5>
6877<pre>
6878 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6879 %sum = extractvalue {i32, i1} %res, 0
6880 %obit = extractvalue {i32, i1} %res, 1
6881 br i1 %obit, label %overflow, label %normal
6882</pre>
6883
6884</div>
6885
6886<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6887<h4>
6888 <a name="int_usub_overflow">
6889 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6890 </a>
6891</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6892
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6893<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6894
6895<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6896<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]6897 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6898
6899<pre>
6900 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6901 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6902 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6903</pre>
6904
6905<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6906<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6907 an unsigned subtraction of the two arguments, and indicate whether an
6908 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6909
6910<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6911<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]6912 be of integer types of any bit width, but they must have the same bit
6913 width. The second element of the result structure must be of
6914 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6915 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6916
6917<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6918<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6919 an unsigned subtraction of the two arguments. They return a structure &mdash;
6920 the first element of which is the subtraction, and the second element of
6921 which is a bit specifying if the unsigned subtraction resulted in an
6922 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6923
6924<h5>Examples:</h5>
6925<pre>
6926 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6927 %sum = extractvalue {i32, i1} %res, 0
6928 %obit = extractvalue {i32, i1} %res, 1
6929 br i1 %obit, label %overflow, label %normal
6930</pre>
6931
6932</div>
6933
6934<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6935<h4>
6936 <a name="int_smul_overflow">
6937 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6938 </a>
6939</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6940
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6941<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6942
6943<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6944<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]6945 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6946
6947<pre>
6948 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6949 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6950 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6951</pre>
6952
6953<h5>Overview:</h5>
6954
6955<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6956 a signed multiplication of the two arguments, and indicate whether an
6957 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6958
6959<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6960<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]6961 be of integer types of any bit width, but they must have the same bit
6962 width. The second element of the result structure must be of
6963 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6964 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6965
6966<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6967<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6968 a signed multiplication of the two arguments. They return a structure &mdash;
6969 the first element of which is the multiplication, and the second element of
6970 which is a bit specifying if the signed multiplication resulted in an
6971 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6972
6973<h5>Examples:</h5>
6974<pre>
6975 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6976 %sum = extractvalue {i32, i1} %res, 0
6977 %obit = extractvalue {i32, i1} %res, 1
6978 br i1 %obit, label %overflow, label %normal
6979</pre>
6980
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6981</div>
6982
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6983<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6984<h4>
6985 <a name="int_umul_overflow">
6986 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
6987 </a>
6988</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6989
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6990<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6991
6992<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6993<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]6994 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6995
6996<pre>
6997 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6998 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6999 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7000</pre>
7001
7002<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7003<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7004 a unsigned multiplication of the two arguments, and indicate whether an
7005 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7006
7007<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7008<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]7009 be of integer types of any bit width, but they must have the same bit
7010 width. The second element of the result structure must be of
7011 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7012 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7013
7014<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7015<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7016 an unsigned multiplication of the two arguments. They return a structure
7017 &mdash; the first element of which is the multiplication, and the second
7018 element of which is a bit specifying if the unsigned multiplication resulted
7019 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7020
7021<h5>Examples:</h5>
7022<pre>
7023 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7024 %sum = extractvalue {i32, i1} %res, 0
7025 %obit = extractvalue {i32, i1} %res, 1
7026 br i1 %obit, label %overflow, label %normal
7027</pre>
7028
7029</div>
7030
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7031</div>
7032
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7033<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7034<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7035 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7036</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7037
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7038<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7039
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7040<p>Half precision floating point is a storage-only format. This means that it is
7041 a dense encoding (in memory) but does not support computation in the
7042 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7043
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7044<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7045 value as an i16, then convert it to float with <a
7046 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7047 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7048 double etc). To store the value back to memory, it is first converted to
7049 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7050 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7051 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7052
7053<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7054<h4>
7055 <a name="int_convert_to_fp16">
7056 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7057 </a>
7058</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7059
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7060<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7061
7062<h5>Syntax:</h5>
7063<pre>
7064 declare i16 @llvm.convert.to.fp16(f32 %a)
7065</pre>
7066
7067<h5>Overview:</h5>
7068<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7069 a conversion from single precision floating point format to half precision
7070 floating point format.</p>
7071
7072<h5>Arguments:</h5>
7073<p>The intrinsic function contains single argument - the value to be
7074 converted.</p>
7075
7076<h5>Semantics:</h5>
7077<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7078 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7079 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7080 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7081
7082<h5>Examples:</h5>
7083<pre>
7084 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7085 store i16 %res, i16* @x, align 2
7086</pre>
7087
7088</div>
7089
7090<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7091<h4>
7092 <a name="int_convert_from_fp16">
7093 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7094 </a>
7095</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7096
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7097<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7098
7099<h5>Syntax:</h5>
7100<pre>
7101 declare f32 @llvm.convert.from.fp16(i16 %a)
7102</pre>
7103
7104<h5>Overview:</h5>
7105<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7106 a conversion from half precision floating point format to single precision
7107 floating point format.</p>
7108
7109<h5>Arguments:</h5>
7110<p>The intrinsic function contains single argument - the value to be
7111 converted.</p>
7112
7113<h5>Semantics:</h5>
7114<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7115 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7116 precision floating point format. The input half-float value is represented by
7117 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7118
7119<h5>Examples:</h5>
7120<pre>
7121 %a = load i16* @x, align 2
7122 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7123</pre>
7124
7125</div>
7126
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7127</div>
7128
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7129<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7130<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7131 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7132</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7133
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7134<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7135
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7136<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7137 prefix), are described in
7138 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7139 Level Debugging</a> document.</p>
7140
7141</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7142
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7143<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7144<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7145 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7146</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7147
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7148<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7149
7150<p>The LLVM exception handling intrinsics (which all start with
7151 <tt>llvm.eh.</tt> prefix), are described in
7152 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7153 Handling</a> document.</p>
7154
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7155</div>
7156
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7157<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7158<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7159 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7160</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7161
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7162<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7163
7164<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7165 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7166 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7167 function pointer lacking the nest parameter - the caller does not need to
7168 provide a value for it. Instead, the value to use is stored in advance in a
7169 "trampoline", a block of memory usually allocated on the stack, which also
7170 contains code to splice the nest value into the argument list. This is used
7171 to implement the GCC nested function address extension.</p>
7172
7173<p>For example, if the function is
7174 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7175 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7176 follows:</p>
7177
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7178<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7179 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7180 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7181 %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]7182 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7183</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7184
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7185<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7186 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7187
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7188<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7189<h4>
7190 <a name="int_it">
7191 '<tt>llvm.init.trampoline</tt>' Intrinsic
7192 </a>
7193</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7194
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7195<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7196
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7197<h5>Syntax:</h5>
7198<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7199 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]7200</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7201
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7202<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7203<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7204 function pointer suitable for executing it.</p>
7205
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7206<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7207<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7208 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7209 sufficiently aligned block of memory; this memory is written to by the
7210 intrinsic. Note that the size and the alignment are target-specific - LLVM
7211 currently provides no portable way of determining them, so a front-end that
7212 generates this intrinsic needs to have some target-specific knowledge.
7213 The <tt>func</tt> argument must hold a function bitcast to
7214 an <tt>i8*</tt>.</p>
7215
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7216<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7217<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7218 dependent code, turning it into a function. A pointer to this function is
7219 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7220 function pointer type</a> before being called. The new function's signature
7221 is the same as that of <tt>func</tt> with any arguments marked with
7222 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7223 is allowed, and it must be of pointer type. Calling the new function is
7224 equivalent to calling <tt>func</tt> with the same argument list, but
7225 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7226 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7227 by <tt>tramp</tt> is modified, then the effect of any later call to the
7228 returned function pointer is undefined.</p>
7229
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7230</div>
7231
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7232</div>
7233
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7234<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7235<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7236 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7237</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7238
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7239<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7240
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7241<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7242 hardware constructs for atomic operations and memory synchronization. This
7243 provides an interface to the hardware, not an interface to the programmer. It
7244 is aimed at a low enough level to allow any programming models or APIs
7245 (Application Programming Interfaces) which need atomic behaviors to map
7246 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7247 hardware provides a "universal IR" for source languages, it also provides a
7248 starting point for developing a "universal" atomic operation and
7249 synchronization IR.</p>
7250
7251<p>These do <em>not</em> form an API such as high-level threading libraries,
7252 software transaction memory systems, atomic primitives, and intrinsic
7253 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7254 application libraries. The hardware interface provided by LLVM should allow
7255 a clean implementation of all of these APIs and parallel programming models.
7256 No one model or paradigm should be selected above others unless the hardware
7257 itself ubiquitously does so.</p>
7258
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7259<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7260<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7261 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7262</h4>
7263
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7264<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7265<h5>Syntax:</h5>
7266<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7267 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]7268</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7269
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7270<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7271<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7272 specific pairs of memory access types.</p>
7273
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7274<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7275<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7276 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7277 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7278 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7279
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7280<ul>
7281 <li><tt>ll</tt>: load-load barrier</li>
7282 <li><tt>ls</tt>: load-store barrier</li>
7283 <li><tt>sl</tt>: store-load barrier</li>
7284 <li><tt>ss</tt>: store-store barrier</li>
7285 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7286</ul>
7287
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7288<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7289<p>This intrinsic causes the system to enforce some ordering constraints upon
7290 the loads and stores of the program. This barrier does not
7291 indicate <em>when</em> any events will occur, it only enforces
7292 an <em>order</em> in which they occur. For any of the specified pairs of load
7293 and store operations (f.ex. load-load, or store-load), all of the first
7294 operations preceding the barrier will complete before any of the second
7295 operations succeeding the barrier begin. Specifically the semantics for each
7296 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7297
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7298<ul>
7299 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7300 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7301 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7302 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7303 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7304 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7305 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7306 load after the barrier begins.</li>
7307</ul>
7308
7309<p>These semantics are applied with a logical "and" behavior when more than one
7310 is enabled in a single memory barrier intrinsic.</p>
7311
7312<p>Backends may implement stronger barriers than those requested when they do
7313 not support as fine grained a barrier as requested. Some architectures do
7314 not need all types of barriers and on such architectures, these become
7315 noops.</p>
7316
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7317<h5>Example:</h5>
7318<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7319%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7320%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7321 store i32 4, %ptr
7322
7323%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7324 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]7325 <i>; guarantee the above finishes</i>
7326 store i32 8, %ptr <i>; before this begins</i>
7327</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7328
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7329</div>
7330
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7331<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7332<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7333 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7334</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7335
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7336<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7337
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7338<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7339<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7340 any integer bit width and for different address spaces. Not all targets
7341 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7342
7343<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7344 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7345 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7346 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7347 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]7348</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7349
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7350<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7351<p>This loads a value in memory and compares it to a given value. If they are
7352 equal, it stores a new value into the memory.</p>
7353
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7354<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7355<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7356 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7357 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7358 this integer type. While any bit width integer may be used, targets may only
7359 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7360
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7361<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7362<p>This entire intrinsic must be executed atomically. It first loads the value
7363 in memory pointed to by <tt>ptr</tt> and compares it with the
7364 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7365 memory. The loaded value is yielded in all cases. This provides the
7366 equivalent of an atomic compare-and-swap operation within the SSA
7367 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7368
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7369<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7370<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7371%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7372%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7373 store i32 4, %ptr
7374
7375%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7376%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7377 <i>; yields {i32}:result1 = 4</i>
7378%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7379%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7380
7381%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7382%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7383 <i>; yields {i32}:result2 = 8</i>
7384%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7385
7386%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7387</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7388
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7389</div>
7390
7391<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7392<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7393 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7394</h4>
7395
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7396<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7397<h5>Syntax:</h5>
7398
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7399<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7400 integer bit width. Not all targets support all bit widths however.</p>
7401
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7402<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7403 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7404 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7405 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7406 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]7407</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7408
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7409<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7410<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7411 the value from memory. It then stores the value in <tt>val</tt> in the memory
7412 at <tt>ptr</tt>.</p>
7413
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7414<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7415<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7416 the <tt>val</tt> argument and the result must be integers of the same bit
7417 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7418 integer type. The targets may only lower integer representations they
7419 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7420
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7421<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7422<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7423 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7424 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7425
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7426<h5>Examples:</h5>
7427<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7428%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7429%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7430 store i32 4, %ptr
7431
7432%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7433%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7434 <i>; yields {i32}:result1 = 4</i>
7435%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7436%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7437
7438%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7439%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7440 <i>; yields {i32}:result2 = 8</i>
7441
7442%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7443%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7444</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7445
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7446</div>
7447
7448<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7449<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7450 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7451</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7452
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7453<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7454
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7455<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7456<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7457 any integer bit width. Not all targets support all bit widths however.</p>
7458
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7459<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7460 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7461 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7462 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7463 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]7464</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7465
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7466<h5>Overview:</h5>
7467<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7468 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7469
7470<h5>Arguments:</h5>
7471<p>The intrinsic takes two arguments, the first a pointer to an integer value
7472 and the second an integer value. The result is also an integer value. These
7473 integer types can have any bit width, but they must all have the same bit
7474 width. The targets may only lower integer representations they support.</p>
7475
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7476<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7477<p>This intrinsic does a series of operations atomically. It first loads the
7478 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7479 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]7480
7481<h5>Examples:</h5>
7482<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7483%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7484%ptr = bitcast i8* %mallocP to i32*
7485 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7486%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7487 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7488%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7489 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7490%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7491 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7492%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7493</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7494
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7495</div>
7496
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7497<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7498<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7499 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7500</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7501
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7502<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7503
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7504<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7505<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7506 any integer bit width and for different address spaces. Not all targets
7507 support all bit widths however.</p>
7508
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7509<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7510 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7511 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7512 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7513 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]7514</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7515
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7516<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7517<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7518 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7519
7520<h5>Arguments:</h5>
7521<p>The intrinsic takes two arguments, the first a pointer to an integer value
7522 and the second an integer value. The result is also an integer value. These
7523 integer types can have any bit width, but they must all have the same bit
7524 width. The targets may only lower integer representations they support.</p>
7525
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7526<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7527<p>This intrinsic does a series of operations atomically. It first loads the
7528 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7529 result to <tt>ptr</tt>. It yields the original value stored
7530 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7531
7532<h5>Examples:</h5>
7533<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7534%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7535%ptr = bitcast i8* %mallocP to i32*
7536 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7537%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7538 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7539%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7540 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7541%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7542 <i>; yields {i32}:result3 = 2</i>
7543%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7544</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7545
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7546</div>
7547
7548<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7549<h4>
7550 <a name="int_atomic_load_and">
7551 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7552 </a>
7553 <br>
7554 <a name="int_atomic_load_nand">
7555 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7556 </a>
7557 <br>
7558 <a name="int_atomic_load_or">
7559 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7560 </a>
7561 <br>
7562 <a name="int_atomic_load_xor">
7563 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7564 </a>
7565</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7566
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7567<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7568
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7569<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7570<p>These are overloaded intrinsics. You can
7571 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7572 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7573 bit width and for different address spaces. Not all targets support all bit
7574 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7575
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7576<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7577 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7578 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7579 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7580 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]7581</pre>
7582
7583<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7584 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7585 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7586 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7587 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]7588</pre>
7589
7590<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7591 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7592 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7593 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7594 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]7595</pre>
7596
7597<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7598 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7599 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7600 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7601 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]7602</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7603
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7604<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7605<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7606 the value stored in memory at <tt>ptr</tt>. It yields the original value
7607 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7608
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7609<h5>Arguments:</h5>
7610<p>These intrinsics take two arguments, the first a pointer to an integer value
7611 and the second an integer value. The result is also an integer value. These
7612 integer types can have any bit width, but they must all have the same bit
7613 width. The targets may only lower integer representations they support.</p>
7614
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7615<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7616<p>These intrinsics does a series of operations atomically. They first load the
7617 value stored at <tt>ptr</tt>. They then do the bitwise
7618 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7619 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7620
7621<h5>Examples:</h5>
7622<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7623%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7624%ptr = bitcast i8* %mallocP to i32*
7625 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7626%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7627 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7628%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7629 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7630%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7631 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7632%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7633 <i>; yields {i32}:result3 = FF</i>
7634%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7635</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7636
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7637</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7638
7639<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7640<h4>
7641 <a name="int_atomic_load_max">
7642 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7643 </a>
7644 <br>
7645 <a name="int_atomic_load_min">
7646 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7647 </a>
7648 <br>
7649 <a name="int_atomic_load_umax">
7650 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7651 </a>
7652 <br>
7653 <a name="int_atomic_load_umin">
7654 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7655 </a>
7656</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7657
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7658<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7659
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7660<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7661<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7662 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7663 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7664 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7665
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7666<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7667 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7668 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7669 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7670 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]7671</pre>
7672
7673<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7674 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7675 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7676 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7677 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]7678</pre>
7679
7680<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7681 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7682 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7683 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7684 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]7685</pre>
7686
7687<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7688 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7689 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7690 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7691 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]7692</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7693
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7694<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7695<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7696 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7697 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7698
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7699<h5>Arguments:</h5>
7700<p>These intrinsics take two arguments, the first a pointer to an integer value
7701 and the second an integer value. The result is also an integer value. These
7702 integer types can have any bit width, but they must all have the same bit
7703 width. The targets may only lower integer representations they support.</p>
7704
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7705<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7706<p>These intrinsics does a series of operations atomically. They first load the
7707 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7708 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7709 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7710
7711<h5>Examples:</h5>
7712<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7713%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7714%ptr = bitcast i8* %mallocP to i32*
7715 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7716%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7717 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7718%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7719 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7720%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7721 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7722%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7723 <i>; yields {i32}:result3 = 8</i>
7724%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7725</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7726
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7727</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7728
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7729</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7730
7731<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7732<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7733 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7734</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7735
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7736<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7737
7738<p>This class of intrinsics exists to information about the lifetime of memory
7739 objects and ranges where variables are immutable.</p>
7740
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7741<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7742<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7743 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7744</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7745
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7746<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7747
7748<h5>Syntax:</h5>
7749<pre>
7750 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7751</pre>
7752
7753<h5>Overview:</h5>
7754<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7755 object's lifetime.</p>
7756
7757<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7758<p>The first argument is a constant integer representing the size of the
7759 object, or -1 if it is variable sized. The second argument is a pointer to
7760 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7761
7762<h5>Semantics:</h5>
7763<p>This intrinsic indicates that before this point in the code, the value of the
7764 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]7765 never be used and has an undefined value. A load from the pointer that
7766 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7767 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7768
7769</div>
7770
7771<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7772<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7773 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7774</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7775
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7776<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7777
7778<h5>Syntax:</h5>
7779<pre>
7780 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7781</pre>
7782
7783<h5>Overview:</h5>
7784<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7785 object's lifetime.</p>
7786
7787<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7788<p>The first argument is a constant integer representing the size of the
7789 object, or -1 if it is variable sized. The second argument is a pointer to
7790 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7791
7792<h5>Semantics:</h5>
7793<p>This intrinsic indicates that after this point in the code, the value of the
7794 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7795 never be used and has an undefined value. Any stores into the memory object
7796 following this intrinsic may be removed as dead.
7797
7798</div>
7799
7800<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7801<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7802 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7803</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7804
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7805<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7806
7807<h5>Syntax:</h5>
7808<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]7809 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7810</pre>
7811
7812<h5>Overview:</h5>
7813<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7814 a memory object will not change.</p>
7815
7816<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7817<p>The first argument is a constant integer representing the size of the
7818 object, or -1 if it is variable sized. The second argument is a pointer to
7819 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7820
7821<h5>Semantics:</h5>
7822<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7823 the return value, the referenced memory location is constant and
7824 unchanging.</p>
7825
7826</div>
7827
7828<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7829<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7830 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7831</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7832
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7833<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7834
7835<h5>Syntax:</h5>
7836<pre>
7837 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7838</pre>
7839
7840<h5>Overview:</h5>
7841<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7842 a memory object are mutable.</p>
7843
7844<h5>Arguments:</h5>
7845<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7846 The second argument is a constant integer representing the size of the
7847 object, or -1 if it is variable sized and the third argument is a pointer
7848 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7849
7850<h5>Semantics:</h5>
7851<p>This intrinsic indicates that the memory is mutable again.</p>
7852
7853</div>
7854
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7855</div>
7856
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7857<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7858<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7859 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7860</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7861
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7862<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7863
7864<p>This class of intrinsics is designed to be generic and has no specific
7865 purpose.</p>
7866
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7867<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7868<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7869 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7870</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7871
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7872<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7873
7874<h5>Syntax:</h5>
7875<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7876 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]7877</pre>
7878
7879<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7880<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7881
7882<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7883<p>The first argument is a pointer to a value, the second is a pointer to a
7884 global string, the third is a pointer to a global string which is the source
7885 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7886
7887<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7888<p>This intrinsic allows annotation of local variables with arbitrary strings.
7889 This can be useful for special purpose optimizations that want to look for
7890 these annotations. These have no other defined use, they are ignored by code
7891 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7892
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7893</div>
7894
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7895<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7896<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7897 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7898</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7899
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7900<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7901
7902<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7903<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7904 any integer bit width.</p>
7905
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7906<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7907 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7908 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7909 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7910 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7911 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]7912</pre>
7913
7914<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7915<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7916
7917<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7918<p>The first argument is an integer value (result of some expression), the
7919 second is a pointer to a global string, the third is a pointer to a global
7920 string which is the source file name, and the last argument is the line
7921 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7922
7923<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7924<p>This intrinsic allows annotations to be put on arbitrary expressions with
7925 arbitrary strings. This can be useful for special purpose optimizations that
7926 want to look for these annotations. These have no other defined use, they
7927 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7928
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7929</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7930
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7931<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7932<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7933 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7934</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7935
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7936<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7937
7938<h5>Syntax:</h5>
7939<pre>
7940 declare void @llvm.trap()
7941</pre>
7942
7943<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7944<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7945
7946<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7947<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7948
7949<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7950<p>This intrinsics is lowered to the target dependent trap instruction. If the
7951 target does not have a trap instruction, this intrinsic will be lowered to
7952 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7953
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7954</div>
7955
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7956<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7957<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7958 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7959</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7960
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7961<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7962
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7963<h5>Syntax:</h5>
7964<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7965 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7966</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7967
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7968<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7969<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7970 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7971 ensure that it is placed on the stack before local variables.</p>
7972
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7973<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7974<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7975 arguments. The first argument is the value loaded from the stack
7976 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7977 that has enough space to hold the value of the guard.</p>
7978
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7979<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7980<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7981 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7982 stack. This is to ensure that if a local variable on the stack is
7983 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7984 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7985 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7986 function.</p>
7987
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7988</div>
7989
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7990<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7991<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7992 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7993</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7994
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7995<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7996
7997<h5>Syntax:</h5>
7998<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7999 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8000 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8001</pre>
8002
8003<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8004<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8005 the optimizers to determine at compile time whether a) an operation (like
8006 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8007 runtime check for overflow isn't necessary. An object in this context means
8008 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8009
8010<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8011<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8012 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8013 is a boolean 0 or 1. This argument determines whether you want the
8014 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]8015 1, variables are not allowed.</p>
8016
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8017<h5>Semantics:</h5>
8018<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8019 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8020 depending on the <tt>type</tt> argument, if the size cannot be determined at
8021 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8022
8023</div>
8024
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8025</div>
8026
8027</div>
8028
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8029<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8030<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8031<address>
8032 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8033 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8034 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8035 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]8036
8037 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8038 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8039 Last modified: $Date$
8040</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8041
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8042</body>
8043</html>