Gitiles
Code Review Sign In
gerrit-public.fairphone.software / toolchain / llvm-project / 5d284ae8a0c6d01880a264a3dad8c29dac72bfba / . / llvm / docs / LangRef.html
blob: fb3420785e248ae3c5fb76b7515a7ea130b55f24 [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
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner80d73c72009-10-10 18:26:06 +0000[diff] [blame]34 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]46 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]47 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]48 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]49 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]50 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]51 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]52 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame^]53 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]54 </ol>
55 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]56 <li><a href="#typesystem">Type System</a>
57 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]58 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]59 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]60 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]61 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_floating">Floating Point Types</a></li>
63 <li><a href="#t_void">Void Type</a></li>
64 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]65 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]66 </ol>
67 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]68 <li><a href="#t_derived">Derived Types</a>
69 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]70 <li><a href="#t_aggregate">Aggregate Types</a>
71 <ol>
72 <li><a href="#t_array">Array Type</a></li>
73 <li><a href="#t_struct">Structure Type</a></li>
74 <li><a href="#t_pstruct">Packed Structure Type</a></li>
75 <li><a href="#t_union">Union Type</a></li>
76 <li><a href="#t_vector">Vector Type</a></li>
77 </ol>
78 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]79 <li><a href="#t_function">Function Type</a></li>
80 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]81 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]82 </ol>
83 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]84 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]87 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]88 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]89 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]90 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
92 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]93 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]94 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]95 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]96 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]97 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]98 <li><a href="#othervalues">Other Values</a>
99 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]100 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]101 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]102 </ol>
103 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]104 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
105 <ol>
106 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]107 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
108 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]109 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
110 Global Variable</a></li>
111 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
112 Global Variable</a></li>
113 </ol>
114 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]115 <li><a href="#instref">Instruction Reference</a>
116 <ol>
117 <li><a href="#terminators">Terminator Instructions</a>
118 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]119 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
120 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]121 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]122 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]125 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]126 </ol>
127 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]128 <li><a href="#binaryops">Binary Operations</a>
129 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]130 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]131 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]136 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
137 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
138 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]139 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
140 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
141 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]144 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
145 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]146 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
147 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
148 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]149 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]150 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]152 </ol>
153 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]154 <li><a href="#vectorops">Vector Operations</a>
155 <ol>
156 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
157 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
158 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]159 </ol>
160 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]161 <li><a href="#aggregateops">Aggregate Operations</a>
162 <ol>
163 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
164 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
165 </ol>
166 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]167 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]168 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]169 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]170 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
171 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
172 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]173 </ol>
174 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]175 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]176 <ol>
177 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
178 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
179 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
180 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]182 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
184 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]186 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
187 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]188 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]189 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]190 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]191 <li><a href="#otherops">Other Operations</a>
192 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]193 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
194 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]195 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]196 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]198 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]199 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]200 </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 Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]203 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]204 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]205 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
206 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]207 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
208 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
209 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]210 </ol>
211 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]212 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
213 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]214 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
215 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
216 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]217 </ol>
218 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]219 <li><a href="#int_codegen">Code Generator Intrinsics</a>
220 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]221 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
222 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
223 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
224 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
225 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
226 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
227 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]228 </ol>
229 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]230 <li><a href="#int_libc">Standard C Library Intrinsics</a>
231 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]232 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
233 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]237 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]240 </ol>
241 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]242 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]243 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]244 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]245 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
246 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
247 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]248 </ol>
249 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]250 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
251 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]252 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
253 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
254 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
255 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
256 <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]257 <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]258 </ol>
259 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]260 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
261 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]262 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
263 <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]264 </ol>
265 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]266 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]267 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]268 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]269 <ol>
270 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]271 </ol>
272 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]273 <li><a href="#int_atomics">Atomic intrinsics</a>
274 <ol>
275 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
276 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
277 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
278 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
279 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
280 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
281 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
282 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
283 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
284 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
285 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
286 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
287 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
288 </ol>
289 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]290 <li><a href="#int_memorymarkers">Memory Use Markers</a>
291 <ol>
292 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
293 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
294 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
295 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
296 </ol>
297 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]298 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]299 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]300 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]301 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]302 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]303 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]304 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.trap</tt>' Intrinsic</a></li>
306 <li><a href="#int_stackprotector">
307 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]308 <li><a href="#int_objectsize">
309 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]310 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]311 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]312 </ol>
313 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]314</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]315
316<div class="doc_author">
317 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
318 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]319</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]320
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]321<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]322<div class="doc_section"> <a name="abstract">Abstract </a></div>
323<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]325<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]326
327<p>This document is a reference manual for the LLVM assembly language. LLVM is
328 a Static Single Assignment (SSA) based representation that provides type
329 safety, low-level operations, flexibility, and the capability of representing
330 'all' high-level languages cleanly. It is the common code representation
331 used throughout all phases of the LLVM compilation strategy.</p>
332
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]333</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]334
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]335<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]336<div class="doc_section"> <a name="introduction">Introduction</a> </div>
337<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]338
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]339<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]340
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]341<p>The LLVM code representation is designed to be used in three different forms:
342 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
343 for fast loading by a Just-In-Time compiler), and as a human readable
344 assembly language representation. This allows LLVM to provide a powerful
345 intermediate representation for efficient compiler transformations and
346 analysis, while providing a natural means to debug and visualize the
347 transformations. The three different forms of LLVM are all equivalent. This
348 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]349
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]350<p>The LLVM representation aims to be light-weight and low-level while being
351 expressive, typed, and extensible at the same time. It aims to be a
352 "universal IR" of sorts, by being at a low enough level that high-level ideas
353 may be cleanly mapped to it (similar to how microprocessors are "universal
354 IR's", allowing many source languages to be mapped to them). By providing
355 type information, LLVM can be used as the target of optimizations: for
356 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]357 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]358 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]359
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]360</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]361
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]362<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]363<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]364
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]365<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]366
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]367<p>It is important to note that this document describes 'well formed' LLVM
368 assembly language. There is a difference between what the parser accepts and
369 what is considered 'well formed'. For example, the following instruction is
370 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]371
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]372<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]373<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]374%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]376</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]377
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]378<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
379 LLVM infrastructure provides a verification pass that may be used to verify
380 that an LLVM module is well formed. This pass is automatically run by the
381 parser after parsing input assembly and by the optimizer before it outputs
382 bitcode. The violations pointed out by the verifier pass indicate bugs in
383 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]384
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]385</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]386
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]387<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]388
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]389<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]390<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]391<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]392
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]393<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]394
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]395<p>LLVM identifiers come in two basic types: global and local. Global
396 identifiers (functions, global variables) begin with the <tt>'@'</tt>
397 character. Local identifiers (register names, types) begin with
398 the <tt>'%'</tt> character. Additionally, there are three different formats
399 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]400
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]401<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]402 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]403 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
404 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
405 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
406 other characters in their names can be surrounded with quotes. Special
407 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
408 ASCII code for the character in hexadecimal. In this way, any character
409 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]410
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]411 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]412 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]413
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]414 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]415 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]416</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]417
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]418<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]419 don't need to worry about name clashes with reserved words, and the set of
420 reserved words may be expanded in the future without penalty. Additionally,
421 unnamed identifiers allow a compiler to quickly come up with a temporary
422 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]423
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]424<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]425 languages. There are keywords for different opcodes
426 ('<tt><a href="#i_add">add</a></tt>',
427 '<tt><a href="#i_bitcast">bitcast</a></tt>',
428 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
429 ('<tt><a href="#t_void">void</a></tt>',
430 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
431 reserved words cannot conflict with variable names, because none of them
432 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]433
434<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]435 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]436
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]437<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]439<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]440<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]441%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]443</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]445<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]447<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]449%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]450</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]451</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]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
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]455<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456<pre>
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]457%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
458%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]459%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]460</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]461</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]462
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]463<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
464 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]466<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]468 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]469
470 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]471 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]472
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]473 <li>Unnamed temporaries are numbered sequentially</li>
474</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]475
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]476<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]477 demonstrating instructions, we will follow an instruction with a comment that
478 defines the type and name of value produced. Comments are shown in italic
479 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]480
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]481</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]482
483<!-- *********************************************************************** -->
484<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
485<!-- *********************************************************************** -->
486
487<!-- ======================================================================= -->
488<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
489</div>
490
491<div class="doc_text">
492
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]493<p>LLVM programs are composed of "Module"s, each of which is a translation unit
494 of the input programs. Each module consists of functions, global variables,
495 and symbol table entries. Modules may be combined together with the LLVM
496 linker, which merges function (and global variable) definitions, resolves
497 forward declarations, and merges symbol table entries. Here is an example of
498 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]499
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]500<div class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]501<pre>
502<i>; Declare the string constant as a global constant.</i>
503<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]504
505<i>; External declaration of the puts function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]506<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]507
508<i>; Definition of main function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]509define i32 @main() { <i>; i32()* </i>
510 <i>; Convert [13 x i8]* to i8 *...</i>
511 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]512
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]513 <i>; Call puts function to write out the string to stdout.</i>
514 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]515 <a href="#i_ret">ret</a> i32 0<br>}
516
517<i>; Named metadata</i>
518!1 = metadata !{i32 41}
519!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]520</pre>
521</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]522
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523<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]524 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]525 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]526 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
527 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]528
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]529<p>In general, a module is made up of a list of global values, where both
530 functions and global variables are global values. Global values are
531 represented by a pointer to a memory location (in this case, a pointer to an
532 array of char, and a pointer to a function), and have one of the
533 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]534
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]535</div>
536
537<!-- ======================================================================= -->
538<div class="doc_subsection">
539 <a name="linkage">Linkage Types</a>
540</div>
541
542<div class="doc_text">
543
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]544<p>All Global Variables and Functions have one of the following types of
545 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]546
547<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]549 <dd>Global values with private linkage are only directly accessible by objects
550 in the current module. In particular, linking code into a module with an
551 private global value may cause the private to be renamed as necessary to
552 avoid collisions. Because the symbol is private to the module, all
553 references can be updated. This doesn't show up in any symbol table in the
554 object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]555
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]556 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]557 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere7f064e2009-08-24 04:32:16 +0000[diff] [blame]558 removed by the linker after evaluation. Note that (unlike private
559 symbols) linker_private symbols are subject to coalescing by the linker:
560 weak symbols get merged and redefinitions are rejected. However, unlike
561 normal strong symbols, they are removed by the linker from the final
562 linked image (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]563
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]564 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]565 <dd>Similar to private, but the value shows as a local symbol
566 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
567 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]568
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]569 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]570 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]571 into the object file corresponding to the LLVM module. They exist to
572 allow inlining and other optimizations to take place given knowledge of
573 the definition of the global, which is known to be somewhere outside the
574 module. Globals with <tt>available_externally</tt> linkage are allowed to
575 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
576 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]577
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]578 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]579 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]580 the same name when linkage occurs. This can be used to implement
581 some forms of inline functions, templates, or other code which must be
582 generated in each translation unit that uses it, but where the body may
583 be overridden with a more definitive definition later. Unreferenced
584 <tt>linkonce</tt> globals are allowed to be discarded. Note that
585 <tt>linkonce</tt> linkage does not actually allow the optimizer to
586 inline the body of this function into callers because it doesn't know if
587 this definition of the function is the definitive definition within the
588 program or whether it will be overridden by a stronger definition.
589 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
590 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]591
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]592 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]593 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
594 <tt>linkonce</tt> linkage, except that unreferenced globals with
595 <tt>weak</tt> linkage may not be discarded. This is used for globals that
596 are declared "weak" in C source code.</dd>
597
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]598 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]599 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
600 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
601 global scope.
602 Symbols with "<tt>common</tt>" linkage are merged in the same way as
603 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]604 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]605 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]606 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
607 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]608
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]609
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]610 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]611 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]612 pointer to array type. When two global variables with appending linkage
613 are linked together, the two global arrays are appended together. This is
614 the LLVM, typesafe, equivalent of having the system linker append together
615 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]616
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]617 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]618 <dd>The semantics of this linkage follow the ELF object file model: the symbol
619 is weak until linked, if not linked, the symbol becomes null instead of
620 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]621
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]622 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
623 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]624 <dd>Some languages allow differing globals to be merged, such as two functions
625 with different semantics. Other languages, such as <tt>C++</tt>, ensure
626 that only equivalent globals are ever merged (the "one definition rule" -
627 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
628 and <tt>weak_odr</tt> linkage types to indicate that the global will only
629 be merged with equivalent globals. These linkage types are otherwise the
630 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]631
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]632 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]633 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]634 visible, meaning that it participates in linkage and can be used to
635 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]636</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]637
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]638<p>The next two types of linkage are targeted for Microsoft Windows platform
639 only. They are designed to support importing (exporting) symbols from (to)
640 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]641
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]642<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]643 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]644 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]645 or variable via a global pointer to a pointer that is set up by the DLL
646 exporting the symbol. On Microsoft Windows targets, the pointer name is
647 formed by combining <code>__imp_</code> and the function or variable
648 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]649
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]650 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]651 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]652 pointer to a pointer in a DLL, so that it can be referenced with the
653 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
654 name is formed by combining <code>__imp_</code> and the function or
655 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]656</dl>
657
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]658<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
659 another module defined a "<tt>.LC0</tt>" variable and was linked with this
660 one, one of the two would be renamed, preventing a collision. Since
661 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
662 declarations), they are accessible outside of the current module.</p>
663
664<p>It is illegal for a function <i>declaration</i> to have any linkage type
665 other than "externally visible", <tt>dllimport</tt>
666 or <tt>extern_weak</tt>.</p>
667
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]668<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]669 or <tt>weak_odr</tt> linkages.</p>
670
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]671</div>
672
673<!-- ======================================================================= -->
674<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]675 <a name="callingconv">Calling Conventions</a>
676</div>
677
678<div class="doc_text">
679
680<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]681 and <a href="#i_invoke">invokes</a> can all have an optional calling
682 convention specified for the call. The calling convention of any pair of
683 dynamic caller/callee must match, or the behavior of the program is
684 undefined. The following calling conventions are supported by LLVM, and more
685 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]686
687<dl>
688 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]689 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]690 specified) matches the target C calling conventions. This calling
691 convention supports varargs function calls and tolerates some mismatch in
692 the declared prototype and implemented declaration of the function (as
693 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]694
695 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]696 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]697 (e.g. by passing things in registers). This calling convention allows the
698 target to use whatever tricks it wants to produce fast code for the
699 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]700 (Application Binary Interface).
701 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]702 when this or the GHC convention is used.</a> This calling convention
703 does not support varargs and requires the prototype of all callees to
704 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]705
706 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]708 as possible under the assumption that the call is not commonly executed.
709 As such, these calls often preserve all registers so that the call does
710 not break any live ranges in the caller side. This calling convention
711 does not support varargs and requires the prototype of all callees to
712 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]713
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]714 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
715 <dd>This calling convention has been implemented specifically for use by the
716 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
717 It passes everything in registers, going to extremes to achieve this by
718 disabling callee save registers. This calling convention should not be
719 used lightly but only for specific situations such as an alternative to
720 the <em>register pinning</em> performance technique often used when
721 implementing functional programming languages.At the moment only X86
722 supports this convention and it has the following limitations:
723 <ul>
724 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
725 floating point types are supported.</li>
726 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
727 6 floating point parameters.</li>
728 </ul>
729 This calling convention supports
730 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
731 requires both the caller and callee are using it.
732 </dd>
733
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]734 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]735 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]736 target-specific calling conventions to be used. Target specific calling
737 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]738</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]739
740<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]741 support Pascal conventions or any other well-known target-independent
742 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]743
744</div>
745
746<!-- ======================================================================= -->
747<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]748 <a name="visibility">Visibility Styles</a>
749</div>
750
751<div class="doc_text">
752
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]753<p>All Global Variables and Functions have one of the following visibility
754 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]755
756<dl>
757 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]758 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]759 that the declaration is visible to other modules and, in shared libraries,
760 means that the declared entity may be overridden. On Darwin, default
761 visibility means that the declaration is visible to other modules. Default
762 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763
764 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]765 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]766 object if they are in the same shared object. Usually, hidden visibility
767 indicates that the symbol will not be placed into the dynamic symbol
768 table, so no other module (executable or shared library) can reference it
769 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]770
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]771 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]772 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]773 the dynamic symbol table, but that references within the defining module
774 will bind to the local symbol. That is, the symbol cannot be overridden by
775 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]776</dl>
777
778</div>
779
780<!-- ======================================================================= -->
781<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]782 <a name="namedtypes">Named Types</a>
783</div>
784
785<div class="doc_text">
786
787<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]788 it easier to read the IR and make the IR more condensed (particularly when
789 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]790
791<div class="doc_code">
792<pre>
793%mytype = type { %mytype*, i32 }
794</pre>
795</div>
796
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]797<p>You may give a name to any <a href="#typesystem">type</a> except
798 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
799 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]800
801<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]802 and that you can therefore specify multiple names for the same type. This
803 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
804 uses structural typing, the name is not part of the type. When printing out
805 LLVM IR, the printer will pick <em>one name</em> to render all types of a
806 particular shape. This means that if you have code where two different
807 source types end up having the same LLVM type, that the dumper will sometimes
808 print the "wrong" or unexpected type. This is an important design point and
809 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]810
811</div>
812
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]813<!-- ======================================================================= -->
814<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]815 <a name="globalvars">Global Variables</a>
816</div>
817
818<div class="doc_text">
819
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]820<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]821 instead of run-time. Global variables may optionally be initialized, may
822 have an explicit section to be placed in, and may have an optional explicit
823 alignment specified. A variable may be defined as "thread_local", which
824 means that it will not be shared by threads (each thread will have a
825 separated copy of the variable). A variable may be defined as a global
826 "constant," which indicates that the contents of the variable
827 will <b>never</b> be modified (enabling better optimization, allowing the
828 global data to be placed in the read-only section of an executable, etc).
829 Note that variables that need runtime initialization cannot be marked
830 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]831
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]832<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
833 constant, even if the final definition of the global is not. This capability
834 can be used to enable slightly better optimization of the program, but
835 requires the language definition to guarantee that optimizations based on the
836 'constantness' are valid for the translation units that do not include the
837 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]838
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]839<p>As SSA values, global variables define pointer values that are in scope
840 (i.e. they dominate) all basic blocks in the program. Global variables
841 always define a pointer to their "content" type because they describe a
842 region of memory, and all memory objects in LLVM are accessed through
843 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]844
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]845<p>A global variable may be declared to reside in a target-specific numbered
846 address space. For targets that support them, address spaces may affect how
847 optimizations are performed and/or what target instructions are used to
848 access the variable. The default address space is zero. The address space
849 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]850
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]851<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]852 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]853
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]854<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]855 the alignment is set to zero, the alignment of the global is set by the
856 target to whatever it feels convenient. If an explicit alignment is
857 specified, the global is forced to have at least that much alignment. All
858 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]859
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]860<p>For example, the following defines a global in a numbered address space with
861 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]862
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]863<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]864<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]865@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]866</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]867</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]868
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]869</div>
870
871
872<!-- ======================================================================= -->
873<div class="doc_subsection">
874 <a name="functionstructure">Functions</a>
875</div>
876
877<div class="doc_text">
878
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]879<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]880 optional <a href="#linkage">linkage type</a>, an optional
881 <a href="#visibility">visibility style</a>, an optional
882 <a href="#callingconv">calling convention</a>, a return type, an optional
883 <a href="#paramattrs">parameter attribute</a> for the return type, a function
884 name, a (possibly empty) argument list (each with optional
885 <a href="#paramattrs">parameter attributes</a>), optional
886 <a href="#fnattrs">function attributes</a>, an optional section, an optional
887 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
888 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]889
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]890<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
891 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]892 <a href="#visibility">visibility style</a>, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]893 <a href="#callingconv">calling convention</a>, a return type, an optional
894 <a href="#paramattrs">parameter attribute</a> for the return type, a function
895 name, a possibly empty list of arguments, an optional alignment, and an
896 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]897
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]898<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]899 (Control Flow Graph) for the function. Each basic block may optionally start
900 with a label (giving the basic block a symbol table entry), contains a list
901 of instructions, and ends with a <a href="#terminators">terminator</a>
902 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]903
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]904<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]905 executed on entrance to the function, and it is not allowed to have
906 predecessor basic blocks (i.e. there can not be any branches to the entry
907 block of a function). Because the block can have no predecessors, it also
908 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]909
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]910<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]911 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]912
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]913<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]914 the alignment is set to zero, the alignment of the function is set by the
915 target to whatever it feels convenient. If an explicit alignment is
916 specified, the function is forced to have at least that much alignment. All
917 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]918
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]919<h5>Syntax:</h5>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]920<div class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]921<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]922define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]923 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
924 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
925 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
926 [<a href="#gc">gc</a>] { ... }
927</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]928</div>
929
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]930</div>
931
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]932<!-- ======================================================================= -->
933<div class="doc_subsection">
934 <a name="aliasstructure">Aliases</a>
935</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]936
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]937<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]938
939<p>Aliases act as "second name" for the aliasee value (which can be either
940 function, global variable, another alias or bitcast of global value). Aliases
941 may have an optional <a href="#linkage">linkage type</a>, and an
942 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]943
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]944<h5>Syntax:</h5>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]945<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]946<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]947@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]948</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]949</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]950
951</div>
952
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]953<!-- ======================================================================= -->
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]954<div class="doc_subsection">
955 <a name="namedmetadatastructure">Named Metadata</a>
956</div>
957
958<div class="doc_text">
959
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]960<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
961 nodes</a> (but not metadata strings) and null are the only valid operands for
962 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]963
964<h5>Syntax:</h5>
965<div class="doc_code">
966<pre>
967!1 = metadata !{metadata !"one"}
968!name = !{null, !1}
969</pre>
970</div>
971
972</div>
973
974<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]975<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]976
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]977<div class="doc_text">
978
979<p>The return type and each parameter of a function type may have a set of
980 <i>parameter attributes</i> associated with them. Parameter attributes are
981 used to communicate additional information about the result or parameters of
982 a function. Parameter attributes are considered to be part of the function,
983 not of the function type, so functions with different parameter attributes
984 can have the same function type.</p>
985
986<p>Parameter attributes are simple keywords that follow the type specified. If
987 multiple parameter attributes are needed, they are space separated. For
988 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]989
990<div class="doc_code">
991<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]992declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]993declare i32 @atoi(i8 zeroext)
994declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]995</pre>
996</div>
997
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]998<p>Note that any attributes for the function result (<tt>nounwind</tt>,
999 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1000
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1001<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1002
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1003<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1004 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1005 <dd>This indicates to the code generator that the parameter or return value
1006 should be zero-extended to a 32-bit value by the caller (for a parameter)
1007 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1008
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1009 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1010 <dd>This indicates to the code generator that the parameter or return value
1011 should be sign-extended to a 32-bit value by the caller (for a parameter)
1012 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1013
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1014 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1015 <dd>This indicates that this parameter or return value should be treated in a
1016 special target-dependent fashion during while emitting code for a function
1017 call or return (usually, by putting it in a register as opposed to memory,
1018 though some targets use it to distinguish between two different kinds of
1019 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1020
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1021 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1022 <dd>This indicates that the pointer parameter should really be passed by value
1023 to the function. The attribute implies that a hidden copy of the pointee
1024 is made between the caller and the callee, so the callee is unable to
1025 modify the value in the callee. This attribute is only valid on LLVM
1026 pointer arguments. It is generally used to pass structs and arrays by
1027 value, but is also valid on pointers to scalars. The copy is considered
1028 to belong to the caller not the callee (for example,
1029 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1030 <tt>byval</tt> parameters). This is not a valid attribute for return
1031 values. The byval attribute also supports specifying an alignment with
1032 the align attribute. This has a target-specific effect on the code
1033 generator that usually indicates a desired alignment for the synthesized
1034 stack slot.</dd>
1035
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1036 <dt><tt><b>sret</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This indicates that the pointer parameter specifies the address of a
1038 structure that is the return value of the function in the source program.
1039 This pointer must be guaranteed by the caller to be valid: loads and
1040 stores to the structure may be assumed by the callee to not to trap. This
1041 may only be applied to the first parameter. This is not a valid attribute
1042 for return values. </dd>
1043
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1044 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1045 <dd>This indicates that the pointer does not alias any global or any other
1046 parameter. The caller is responsible for ensuring that this is the
1047 case. On a function return value, <tt>noalias</tt> additionally indicates
1048 that the pointer does not alias any other pointers visible to the
1049 caller. For further details, please see the discussion of the NoAlias
1050 response in
1051 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1052 analysis</a>.</dd>
1053
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1054 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1055 <dd>This indicates that the callee does not make any copies of the pointer
1056 that outlive the callee itself. This is not a valid attribute for return
1057 values.</dd>
1058
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1059 <dt><tt><b>nest</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1060 <dd>This indicates that the pointer parameter can be excised using the
1061 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1062 attribute for return values.</dd>
1063</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1064
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1065</div>
1066
1067<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1068<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1069 <a name="gc">Garbage Collector Names</a>
1070</div>
1071
1072<div class="doc_text">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1073
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1074<p>Each function may specify a garbage collector name, which is simply a
1075 string:</p>
1076
1077<div class="doc_code">
1078<pre>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1079define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1080</pre>
1081</div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1082
1083<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1084 collector which will cause the compiler to alter its output in order to
1085 support the named garbage collection algorithm.</p>
1086
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1087</div>
1088
1089<!-- ======================================================================= -->
1090<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1091 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1092</div>
1093
1094<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1095
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1096<p>Function attributes are set to communicate additional information about a
1097 function. Function attributes are considered to be part of the function, not
1098 of the function type, so functions with different parameter attributes can
1099 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1100
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1101<p>Function attributes are simple keywords that follow the type specified. If
1102 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1103
1104<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1105<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1106define void @f() noinline { ... }
1107define void @f() alwaysinline { ... }
1108define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1109define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1110</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1111</div>
1112
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1113<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1114 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1115 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1116 the backend should forcibly align the stack pointer. Specify the
1117 desired alignment, which must be a power of two, in parentheses.
1118
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1119 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1120 <dd>This attribute indicates that the inliner should attempt to inline this
1121 function into callers whenever possible, ignoring any active inlining size
1122 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1123
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1124 <dt><tt><b>inlinehint</b></tt></dt>
1125 <dd>This attribute indicates that the source code contained a hint that inlining
1126 this function is desirable (such as the "inline" keyword in C/C++). It
1127 is just a hint; it imposes no requirements on the inliner.</dd>
1128
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1129 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1130 <dd>This attribute indicates that the inliner should never inline this
1131 function in any situation. This attribute may not be used together with
1132 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1133
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1134 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1135 <dd>This attribute suggests that optimization passes and code generator passes
1136 make choices that keep the code size of this function low, and otherwise
1137 do optimizations specifically to reduce code size.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1138
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1139 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1140 <dd>This function attribute indicates that the function never returns
1141 normally. This produces undefined behavior at runtime if the function
1142 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1143
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1144 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1145 <dd>This function attribute indicates that the function never returns with an
1146 unwind or exceptional control flow. If the function does unwind, its
1147 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1148
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1149 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1150 <dd>This attribute indicates that the function computes its result (or decides
1151 to unwind an exception) based strictly on its arguments, without
1152 dereferencing any pointer arguments or otherwise accessing any mutable
1153 state (e.g. memory, control registers, etc) visible to caller functions.
1154 It does not write through any pointer arguments
1155 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1156 changes any state visible to callers. This means that it cannot unwind
1157 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1158 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1159
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1160 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1161 <dd>This attribute indicates that the function does not write through any
1162 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1163 arguments) or otherwise modify any state (e.g. memory, control registers,
1164 etc) visible to caller functions. It may dereference pointer arguments
1165 and read state that may be set in the caller. A readonly function always
1166 returns the same value (or unwinds an exception identically) when called
1167 with the same set of arguments and global state. It cannot unwind an
1168 exception by calling the <tt>C++</tt> exception throwing methods, but may
1169 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1170
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1171 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1172 <dd>This attribute indicates that the function should emit a stack smashing
1173 protector. It is in the form of a "canary"&mdash;a random value placed on
1174 the stack before the local variables that's checked upon return from the
1175 function to see if it has been overwritten. A heuristic is used to
1176 determine if a function needs stack protectors or not.<br>
1177<br>
1178 If a function that has an <tt>ssp</tt> attribute is inlined into a
1179 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1180 function will have an <tt>ssp</tt> attribute.</dd>
1181
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1182 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1183 <dd>This attribute indicates that the function should <em>always</em> emit a
1184 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1185 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1186<br>
1187 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1188 function that doesn't have an <tt>sspreq</tt> attribute or which has
1189 an <tt>ssp</tt> attribute, then the resulting function will have
1190 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1191
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1192 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1193 <dd>This attribute indicates that the code generator should not use a red
1194 zone, even if the target-specific ABI normally permits it.</dd>
1195
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1196 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1197 <dd>This attributes disables implicit floating point instructions.</dd>
1198
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1199 <dt><tt><b>naked</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1200 <dd>This attribute disables prologue / epilogue emission for the function.
1201 This can have very system-specific consequences.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1202</dl>
1203
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1204</div>
1205
1206<!-- ======================================================================= -->
1207<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1208 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1209</div>
1210
1211<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1212
1213<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1214 the GCC "file scope inline asm" blocks. These blocks are internally
1215 concatenated by LLVM and treated as a single unit, but may be separated in
1216 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1217
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1218<div class="doc_code">
1219<pre>
1220module asm "inline asm code goes here"
1221module asm "more can go here"
1222</pre>
1223</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1224
1225<p>The strings can contain any character by escaping non-printable characters.
1226 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]1227 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1228
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1229<p>The inline asm code is simply printed to the machine code .s file when
1230 assembly code is generated.</p>
1231
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1232</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1233
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1234<!-- ======================================================================= -->
1235<div class="doc_subsection">
1236 <a name="datalayout">Data Layout</a>
1237</div>
1238
1239<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1240
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1241<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1242 data is to be laid out in memory. The syntax for the data layout is
1243 simply:</p>
1244
1245<div class="doc_code">
1246<pre>
1247target datalayout = "<i>layout specification</i>"
1248</pre>
1249</div>
1250
1251<p>The <i>layout specification</i> consists of a list of specifications
1252 separated by the minus sign character ('-'). Each specification starts with
1253 a letter and may include other information after the letter to define some
1254 aspect of the data layout. The specifications accepted are as follows:</p>
1255
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1256<dl>
1257 <dt><tt>E</tt></dt>
1258 <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]1259 bits with the most significance have the lowest address location.</dd>
1260
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1261 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1262 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1263 the bits with the least significance have the lowest address
1264 location.</dd>
1265
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1266 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1267 <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]1268 <i>preferred</i> alignments. All sizes are in bits. Specifying
1269 the <i>pref</i> alignment is optional. If omitted, the
1270 preceding <tt>:</tt> should be omitted too.</dd>
1271
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1272 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1273 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1274 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1275
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1276 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1277 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1278 <i>size</i>.</dd>
1279
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1280 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1281 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1282 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1283 (double).</dd>
1284
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1285 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1286 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1287 <i>size</i>.</dd>
1288
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1289 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1290 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1291 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1292
1293 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1294 <dd>This specifies a set of native integer widths for the target CPU
1295 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1296 "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]1297 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1298 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1299</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1300
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1301<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1302 default set of specifications which are then (possibly) overriden by the
1303 specifications in the <tt>datalayout</tt> keyword. The default specifications
1304 are given in this list:</p>
1305
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1306<ul>
1307 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1308 <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]1309 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1310 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1311 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1312 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1313 <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]1314 alignment of 64-bits</li>
1315 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1316 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1317 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1318 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1319 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1320 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1321</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1322
1323<p>When LLVM is determining the alignment for a given type, it uses the
1324 following rules:</p>
1325
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1326<ol>
1327 <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]1328 specification is used.</li>
1329
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1330 <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]1331 smallest integer type that is larger than the bitwidth of the sought type
1332 is used. If none of the specifications are larger than the bitwidth then
1333 the the largest integer type is used. For example, given the default
1334 specifications above, the i7 type will use the alignment of i8 (next
1335 largest) while both i65 and i256 will use the alignment of i64 (largest
1336 specified).</li>
1337
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1338 <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]1339 largest vector type that is smaller than the sought vector type will be
1340 used as a fall back. This happens because &lt;128 x double&gt; can be
1341 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1342</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1343
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1344</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1345
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1346<!-- ======================================================================= -->
1347<div class="doc_subsection">
1348 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1349</div>
1350
1351<div class="doc_text">
1352
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1353<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1354with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1355is undefined. Pointer values are associated with address ranges
1356according to the following rules:</p>
1357
1358<ul>
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1359 <li>A pointer value formed from a
1360 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1361 is associated with the addresses associated with the first operand
1362 of the <tt>getelementptr</tt>.</li>
1363 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1364 range of the variable's storage.</li>
1365 <li>The result value of an allocation instruction is associated with
1366 the address range of the allocated storage.</li>
1367 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1368 no address.</li>
1369 <li>A pointer value formed by an
1370 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1371 address ranges of all pointer values that contribute (directly or
1372 indirectly) to the computation of the pointer's value.</li>
1373 <li>The result value of a
1374 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1375 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1376 <li>An integer constant other than zero or a pointer value returned
1377 from a function not defined within LLVM may be associated with address
1378 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1379 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1380 allocated by mechanisms provided by LLVM.</li>
1381 </ul>
1382
1383<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1384<tt><a href="#i_load">load</a></tt> merely indicates the size and
1385alignment of the memory from which to load, as well as the
1386interpretation of the value. The first operand of a
1387<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1388and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1389
1390<p>Consequently, type-based alias analysis, aka TBAA, aka
1391<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1392LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1393additional information which specialized optimization passes may use
1394to implement type-based alias analysis.</p>
1395
1396</div>
1397
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame^]1398<!-- ======================================================================= -->
1399<div class="doc_subsection">
1400 <a name="volatile">Volatile Memory Accesses</a>
1401</div>
1402
1403<div class="doc_text">
1404
1405<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1406href="#i_store"><tt>store</tt></a>s, and <a
1407href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1408The optimizers must not change the number of volatile operations or change their
1409order of execution relative to other volatile operations. The optimizers
1410<i>may</i> change the order of volatile operations relative to non-volatile
1411operations. This is not Java's "volatile" and has no cross-thread
1412synchronization behavior.</p>
1413
1414</div>
1415
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1416<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1417<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1418<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1419
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1420<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1421
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1422<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1423 intermediate representation. Being typed enables a number of optimizations
1424 to be performed on the intermediate representation directly, without having
1425 to do extra analyses on the side before the transformation. A strong type
1426 system makes it easier to read the generated code and enables novel analyses
1427 and transformations that are not feasible to perform on normal three address
1428 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1429
1430</div>
1431
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1432<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1433<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1434Classifications</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1435
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1436<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1437
1438<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1439
1440<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1441 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1442 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1443 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1444 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1445 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1446 </tr>
1447 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1448 <td><a href="#t_floating">floating point</a></td>
1449 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1450 </tr>
1451 <tr>
1452 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1453 <td><a href="#t_integer">integer</a>,
1454 <a href="#t_floating">floating point</a>,
1455 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1456 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1457 <a href="#t_struct">structure</a>,
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1458 <a href="#t_union">union</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1459 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1460 <a href="#t_label">label</a>,
1461 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1462 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1463 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1464 <tr>
1465 <td><a href="#t_primitive">primitive</a></td>
1466 <td><a href="#t_label">label</a>,
1467 <a href="#t_void">void</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1468 <a href="#t_floating">floating point</a>,
1469 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1470 </tr>
1471 <tr>
1472 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1473 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1474 <a href="#t_function">function</a>,
1475 <a href="#t_pointer">pointer</a>,
1476 <a href="#t_struct">structure</a>,
1477 <a href="#t_pstruct">packed structure</a>,
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1478 <a href="#t_union">union</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1479 <a href="#t_vector">vector</a>,
1480 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1481 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1482 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1483 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1484</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1485
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1486<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1487 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1488 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1489
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1490</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1491
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1492<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1493<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1494
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1495<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1496
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1497<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1498 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1499
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1500</div>
1501
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1502<!-- _______________________________________________________________________ -->
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1503<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1504
1505<div class="doc_text">
1506
1507<h5>Overview:</h5>
1508<p>The integer type is a very simple type that simply specifies an arbitrary
1509 bit width for the integer type desired. Any bit width from 1 bit to
1510 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1511
1512<h5>Syntax:</h5>
1513<pre>
1514 iN
1515</pre>
1516
1517<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1518 value.</p>
1519
1520<h5>Examples:</h5>
1521<table class="layout">
1522 <tr class="layout">
1523 <td class="left"><tt>i1</tt></td>
1524 <td class="left">a single-bit integer.</td>
1525 </tr>
1526 <tr class="layout">
1527 <td class="left"><tt>i32</tt></td>
1528 <td class="left">a 32-bit integer.</td>
1529 </tr>
1530 <tr class="layout">
1531 <td class="left"><tt>i1942652</tt></td>
1532 <td class="left">a really big integer of over 1 million bits.</td>
1533 </tr>
1534</table>
1535
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1536</div>
1537
1538<!-- _______________________________________________________________________ -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1539<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1540
1541<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1542
1543<table>
1544 <tbody>
1545 <tr><th>Type</th><th>Description</th></tr>
1546 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1547 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1548 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1549 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1550 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1551 </tbody>
1552</table>
1553
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1554</div>
1555
1556<!-- _______________________________________________________________________ -->
1557<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1558
1559<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1560
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1561<h5>Overview:</h5>
1562<p>The void type does not represent any value and has no size.</p>
1563
1564<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1565<pre>
1566 void
1567</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1568
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1569</div>
1570
1571<!-- _______________________________________________________________________ -->
1572<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1573
1574<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1575
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1576<h5>Overview:</h5>
1577<p>The label type represents code labels.</p>
1578
1579<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1580<pre>
1581 label
1582</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1583
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1584</div>
1585
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1586<!-- _______________________________________________________________________ -->
1587<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1588
1589<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1590
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1591<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1592<p>The metadata type represents embedded metadata. No derived types may be
1593 created from metadata except for <a href="#t_function">function</a>
1594 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1595
1596<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1597<pre>
1598 metadata
1599</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1600
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1601</div>
1602
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1603
1604<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1605<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1606
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1607<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1608
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1609<p>The real power in LLVM comes from the derived types in the system. This is
1610 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1611 useful types. Each of these types contain one or more element types which
1612 may be a primitive type, or another derived type. For example, it is
1613 possible to have a two dimensional array, using an array as the element type
1614 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1615
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1616
1617</div>
1618
1619<!-- _______________________________________________________________________ -->
1620<div class="doc_subsubsection"> <a name="t_aggregate">Aggregate Types</a> </div>
1621
1622<div class="doc_text">
1623
1624<p>Aggregate Types are a subset of derived types that can contain multiple
1625 member types. <a href="#t_array">Arrays</a>,
1626 <a href="#t_struct">structs</a>, <a href="#t_vector">vectors</a> and
1627 <a href="#t_union">unions</a> are aggregate types.</p>
1628
1629</div>
1630
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1631</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1632
1633<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1634<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1635
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1636<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1637
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1638<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1639<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1640 sequentially in memory. The array type requires a size (number of elements)
1641 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1642
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1643<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1644<pre>
1645 [&lt;# elements&gt; x &lt;elementtype&gt;]
1646</pre>
1647
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1648<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1649 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1650
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1651<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1652<table class="layout">
1653 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1654 <td class="left"><tt>[40 x i32]</tt></td>
1655 <td class="left">Array of 40 32-bit integer values.</td>
1656 </tr>
1657 <tr class="layout">
1658 <td class="left"><tt>[41 x i32]</tt></td>
1659 <td class="left">Array of 41 32-bit integer values.</td>
1660 </tr>
1661 <tr class="layout">
1662 <td class="left"><tt>[4 x i8]</tt></td>
1663 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1664 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1665</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1666<p>Here are some examples of multidimensional arrays:</p>
1667<table class="layout">
1668 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1669 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1670 <td class="left">3x4 array of 32-bit integer values.</td>
1671 </tr>
1672 <tr class="layout">
1673 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1674 <td class="left">12x10 array of single precision floating point values.</td>
1675 </tr>
1676 <tr class="layout">
1677 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1678 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1679 </tr>
1680</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1681
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1682<p>There is no restriction on indexing beyond the end of the array implied by
1683 a static type (though there are restrictions on indexing beyond the bounds
1684 of an allocated object in some cases). This means that single-dimension
1685 'variable sized array' addressing can be implemented in LLVM with a zero
1686 length array type. An implementation of 'pascal style arrays' in LLVM could
1687 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1688
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1689</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1690
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1691<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1692<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1693
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1694<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1696<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1697<p>The function type can be thought of as a function signature. It consists of
1698 a return type and a list of formal parameter types. The return type of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1699 function type is a scalar type, a void type, a struct type, or a union
1700 type. If the return type is a struct type then all struct elements must be
1701 of first class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1702
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1703<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1704<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1705 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1706</pre>
1707
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1708<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]1709 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1710 which indicates that the function takes a variable number of arguments.
1711 Variable argument functions can access their arguments with
1712 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1713 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1714 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1715
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1716<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1717<table class="layout">
1718 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1719 <td class="left"><tt>i32 (i32)</tt></td>
1720 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1721 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1722 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1723 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1724 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1725 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1726 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1727 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1728 </td>
1729 </tr><tr class="layout">
1730 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1731 <td class="left">A vararg function that takes at least one
1732 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1733 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1734 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1735 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1736 </tr><tr class="layout">
1737 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1738 <td class="left">A function taking an <tt>i32</tt>, returning a
1739 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1740 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1741 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1742</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1743
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1744</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1745
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1746<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1747<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1748
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1749<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1750
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1751<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1752<p>The structure type is used to represent a collection of data members together
1753 in memory. The packing of the field types is defined to match the ABI of the
1754 underlying processor. The elements of a structure may be any type that has a
1755 size.</p>
1756
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1757<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1758 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1759 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1760 Structures in registers are accessed using the
1761 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1762 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1763<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1764<pre>
1765 { &lt;type list&gt; }
1766</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1767
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1768<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1769<table class="layout">
1770 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1771 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1772 <td class="left">A triple of three <tt>i32</tt> values</td>
1773 </tr><tr class="layout">
1774 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1775 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1776 second element is a <a href="#t_pointer">pointer</a> to a
1777 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1778 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1779 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1780</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1781
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1782</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1783
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1784<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1785<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1786</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1787
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1788<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1789
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1790<h5>Overview:</h5>
1791<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1792 together in memory. There is no padding between fields. Further, the
1793 alignment of a packed structure is 1 byte. The elements of a packed
1794 structure may be any type that has a size.</p>
1795
1796<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1797 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1798 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1799
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1800<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1801<pre>
1802 &lt; { &lt;type list&gt; } &gt;
1803</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1804
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1805<h5>Examples:</h5>
1806<table class="layout">
1807 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1808 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1809 <td class="left">A triple of three <tt>i32</tt> values</td>
1810 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1811 <td class="left">
1812<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1813 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1814 second element is a <a href="#t_pointer">pointer</a> to a
1815 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1816 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1817 </tr>
1818</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1819
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1820</div>
1821
1822<!-- _______________________________________________________________________ -->
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1823<div class="doc_subsubsection"> <a name="t_union">Union Type</a> </div>
1824
1825<div class="doc_text">
1826
1827<h5>Overview:</h5>
1828<p>A union type describes an object with size and alignment suitable for
1829 an object of any one of a given set of types (also known as an "untagged"
1830 union). It is similar in concept and usage to a
1831 <a href="#t_struct">struct</a>, except that all members of the union
1832 have an offset of zero. The elements of a union may be any type that has a
1833 size. Unions must have at least one member - empty unions are not allowed.
1834 </p>
1835
1836<p>The size of the union as a whole will be the size of its largest member,
1837 and the alignment requirements of the union as a whole will be the largest
1838 alignment requirement of any member.</p>
1839
Dan Gohman1ad14992010-02-25 16:51:31 +0000[diff] [blame]1840<p>Union members are accessed using '<tt><a href="#i_load">load</a></tt> and
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1841 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1842 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1843 Since all members are at offset zero, the getelementptr instruction does
1844 not affect the address, only the type of the resulting pointer.</p>
1845
1846<h5>Syntax:</h5>
1847<pre>
1848 union { &lt;type list&gt; }
1849</pre>
1850
1851<h5>Examples:</h5>
1852<table class="layout">
1853 <tr class="layout">
1854 <td class="left"><tt>union { i32, i32*, float }</tt></td>
1855 <td class="left">A union of three types: an <tt>i32</tt>, a pointer to
1856 an <tt>i32</tt>, and a <tt>float</tt>.</td>
1857 </tr><tr class="layout">
1858 <td class="left">
1859 <tt>union {&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1860 <td class="left">A union, where the first element is a <tt>float</tt> and the
1861 second element is a <a href="#t_pointer">pointer</a> to a
1862 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1863 an <tt>i32</tt>.</td>
1864 </tr>
1865</table>
1866
1867</div>
1868
1869<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1870<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1871
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1872<div class="doc_text">
1873
1874<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]1875<p>The pointer type is used to specify memory locations.
1876 Pointers are commonly used to reference objects in memory.</p>
1877
1878<p>Pointer types may have an optional address space attribute defining the
1879 numbered address space where the pointed-to object resides. The default
1880 address space is number zero. The semantics of non-zero address
1881 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1882
1883<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1884 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1885
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1886<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1887<pre>
1888 &lt;type&gt; *
1889</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1890
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1891<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1892<table class="layout">
1893 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1894 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1895 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1896 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1897 </tr>
1898 <tr class="layout">
1899 <td class="left"><tt>i32 (i32 *) *</tt></td>
1900 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1901 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1902 <tt>i32</tt>.</td>
1903 </tr>
1904 <tr class="layout">
1905 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1906 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1907 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1908 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1909</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1910
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1911</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1912
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1913<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1914<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1915
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1916<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1917
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1918<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1919<p>A vector type is a simple derived type that represents a vector of elements.
1920 Vector types are used when multiple primitive data are operated in parallel
1921 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1922 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1923 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1924
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1925<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1926<pre>
1927 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1928</pre>
1929
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1930<p>The number of elements is a constant integer value; elementtype may be any
1931 integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1932
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1933<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1934<table class="layout">
1935 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1936 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1937 <td class="left">Vector of 4 32-bit integer values.</td>
1938 </tr>
1939 <tr class="layout">
1940 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1941 <td class="left">Vector of 8 32-bit floating-point values.</td>
1942 </tr>
1943 <tr class="layout">
1944 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1945 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1946 </tr>
1947</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1948
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1949</div>
1950
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1951<!-- _______________________________________________________________________ -->
1952<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1953<div class="doc_text">
1954
1955<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1956<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1957 corresponds (for example) to the C notion of a forward declared structure
1958 type. In LLVM, opaque types can eventually be resolved to any type (not just
1959 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1960
1961<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1962<pre>
1963 opaque
1964</pre>
1965
1966<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1967<table class="layout">
1968 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1969 <td class="left"><tt>opaque</tt></td>
1970 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1971 </tr>
1972</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1973
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1974</div>
1975
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1976<!-- ======================================================================= -->
1977<div class="doc_subsection">
1978 <a name="t_uprefs">Type Up-references</a>
1979</div>
1980
1981<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1982
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1983<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1984<p>An "up reference" allows you to refer to a lexically enclosing type without
1985 requiring it to have a name. For instance, a structure declaration may
1986 contain a pointer to any of the types it is lexically a member of. Example
1987 of up references (with their equivalent as named type declarations)
1988 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1989
1990<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1991 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1992 { \2 }* %y = type { %y }*
1993 \1* %z = type %z*
1994</pre>
1995
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1996<p>An up reference is needed by the asmprinter for printing out cyclic types
1997 when there is no declared name for a type in the cycle. Because the
1998 asmprinter does not want to print out an infinite type string, it needs a
1999 syntax to handle recursive types that have no names (all names are optional
2000 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2001
2002<h5>Syntax:</h5>
2003<pre>
2004 \&lt;level&gt;
2005</pre>
2006
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2007<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]2008
2009<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2010<table class="layout">
2011 <tr class="layout">
2012 <td class="left"><tt>\1*</tt></td>
2013 <td class="left">Self-referential pointer.</td>
2014 </tr>
2015 <tr class="layout">
2016 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
2017 <td class="left">Recursive structure where the upref refers to the out-most
2018 structure.</td>
2019 </tr>
2020</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2021
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2022</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2023
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2024<!-- *********************************************************************** -->
2025<div class="doc_section"> <a name="constants">Constants</a> </div>
2026<!-- *********************************************************************** -->
2027
2028<div class="doc_text">
2029
2030<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2031 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2032
2033</div>
2034
2035<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]2036<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2037
2038<div class="doc_text">
2039
2040<dl>
2041 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2042 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2043 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2044
2045 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2046 <dd>Standard integers (such as '4') are constants of
2047 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2048 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2049
2050 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2051 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2052 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2053 notation (see below). The assembler requires the exact decimal value of a
2054 floating-point constant. For example, the assembler accepts 1.25 but
2055 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2056 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2057
2058 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2059 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2060 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2061</dl>
2062
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2063<p>The one non-intuitive notation for constants is the hexadecimal form of
2064 floating point constants. For example, the form '<tt>double
2065 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2066 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2067 constants are required (and the only time that they are generated by the
2068 disassembler) is when a floating point constant must be emitted but it cannot
2069 be represented as a decimal floating point number in a reasonable number of
2070 digits. For example, NaN's, infinities, and other special values are
2071 represented in their IEEE hexadecimal format so that assembly and disassembly
2072 do not cause any bits to change in the constants.</p>
2073
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2074<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2075 represented using the 16-digit form shown above (which matches the IEEE754
2076 representation for double); float values must, however, be exactly
2077 representable as IEE754 single precision. Hexadecimal format is always used
2078 for long double, and there are three forms of long double. The 80-bit format
2079 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2080 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2081 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2082 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2083 currently supported target uses this format. Long doubles will only work if
2084 they match the long double format on your target. All hexadecimal formats
2085 are big-endian (sign bit at the left).</p>
2086
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2087</div>
2088
2089<!-- ======================================================================= -->
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2090<div class="doc_subsection">
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2091<a name="aggregateconstants"></a> <!-- old anchor -->
2092<a name="complexconstants">Complex Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2093</div>
2094
2095<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2096
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2097<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2098 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2099
2100<dl>
2101 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2102 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2103 type definitions (a comma separated list of elements, surrounded by braces
2104 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2105 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2106 Structure constants must have <a href="#t_struct">structure type</a>, and
2107 the number and types of elements must match those specified by the
2108 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2109
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2110 <dt><b>Union constants</b></dt>
2111 <dd>Union constants are represented with notation similar to a structure with
2112 a single element - that is, a single typed element surrounded
2113 by braces (<tt>{}</tt>)). For example: "<tt>{ i32 4 }</tt>". The
2114 <a href="#t_union">union type</a> can be initialized with a single-element
2115 struct as long as the type of the struct element matches the type of
2116 one of the union members.</dd>
2117
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2118 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2119 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2120 definitions (a comma separated list of elements, surrounded by square
2121 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2122 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2123 the number and types of elements must match those specified by the
2124 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2125
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2126 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2127 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2128 definitions (a comma separated list of elements, surrounded by
2129 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2130 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2131 have <a href="#t_vector">vector type</a>, and the number and types of
2132 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2133
2134 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2135 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2136 value to zero of <em>any</em> type, including scalar and
2137 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2138 This is often used to avoid having to print large zero initializers
2139 (e.g. for large arrays) and is always exactly equivalent to using explicit
2140 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2141
2142 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2143 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2144 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2145 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2146 be interpreted as part of the instruction stream, metadata is a place to
2147 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2148</dl>
2149
2150</div>
2151
2152<!-- ======================================================================= -->
2153<div class="doc_subsection">
2154 <a name="globalconstants">Global Variable and Function Addresses</a>
2155</div>
2156
2157<div class="doc_text">
2158
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2159<p>The addresses of <a href="#globalvars">global variables</a>
2160 and <a href="#functionstructure">functions</a> are always implicitly valid
2161 (link-time) constants. These constants are explicitly referenced when
2162 the <a href="#identifiers">identifier for the global</a> is used and always
2163 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2164 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2165
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2166<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2167<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2168@X = global i32 17
2169@Y = global i32 42
2170@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2171</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2172</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2173
2174</div>
2175
2176<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]2177<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2178<div class="doc_text">
2179
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2180<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]2181 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2182 Undefined values may be of any type (other than label or void) and be used
2183 anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2184
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2185<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2186 program is well defined no matter what value is used. This gives the
2187 compiler more freedom to optimize. Here are some examples of (potentially
2188 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2189
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2190
2191<div class="doc_code">
2192<pre>
2193 %A = add %X, undef
2194 %B = sub %X, undef
2195 %C = xor %X, undef
2196Safe:
2197 %A = undef
2198 %B = undef
2199 %C = undef
2200</pre>
2201</div>
2202
2203<p>This is safe because all of the output bits are affected by the undef bits.
2204Any output bit can have a zero or one depending on the input bits.</p>
2205
2206<div class="doc_code">
2207<pre>
2208 %A = or %X, undef
2209 %B = and %X, undef
2210Safe:
2211 %A = -1
2212 %B = 0
2213Unsafe:
2214 %A = undef
2215 %B = undef
2216</pre>
2217</div>
2218
2219<p>These logical operations have bits that are not always affected by the input.
2220For example, if "%X" has a zero bit, then the output of the 'and' operation will
2221always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2222such, it is unsafe to optimize or assume that the result of the and is undef.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2223However, it is safe to assume that all bits of the undef could be 0, and
2224optimize the and to 0. Likewise, it is safe to assume that all the bits of
2225the undef operand to the or could be set, allowing the or to be folded to
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2226-1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2227
2228<div class="doc_code">
2229<pre>
2230 %A = select undef, %X, %Y
2231 %B = select undef, 42, %Y
2232 %C = select %X, %Y, undef
2233Safe:
2234 %A = %X (or %Y)
2235 %B = 42 (or %Y)
2236 %C = %Y
2237Unsafe:
2238 %A = undef
2239 %B = undef
2240 %C = undef
2241</pre>
2242</div>
2243
2244<p>This set of examples show that undefined select (and conditional branch)
2245conditions can go "either way" but they have to come from one of the two
2246operands. In the %A example, if %X and %Y were both known to have a clear low
2247bit, then %A would have to have a cleared low bit. However, in the %C example,
2248the optimizer is allowed to assume that the undef operand could be the same as
2249%Y, allowing the whole select to be eliminated.</p>
2250
2251
2252<div class="doc_code">
2253<pre>
2254 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2255
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2256 %B = undef
2257 %C = xor %B, %B
2258
2259 %D = undef
2260 %E = icmp lt %D, 4
2261 %F = icmp gte %D, 4
2262
2263Safe:
2264 %A = undef
2265 %B = undef
2266 %C = undef
2267 %D = undef
2268 %E = undef
2269 %F = undef
2270</pre>
2271</div>
2272
2273<p>This example points out that two undef operands are not necessarily the same.
2274This can be surprising to people (and also matches C semantics) where they
2275assume that "X^X" is always zero, even if X is undef. This isn't true for a
2276number of reasons, but the short answer is that an undef "variable" can
2277arbitrarily change its value over its "live range". This is true because the
2278"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2279logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2280so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner6760e542009-09-08 15:13:16 +0000[diff] [blame]2281to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2282would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2283
2284<div class="doc_code">
2285<pre>
2286 %A = fdiv undef, %X
2287 %B = fdiv %X, undef
2288Safe:
2289 %A = undef
2290b: unreachable
2291</pre>
2292</div>
2293
2294<p>These examples show the crucial difference between an <em>undefined
2295value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2296allowed to have an arbitrary bit-pattern. This means that the %A operation
2297can be constant folded to undef because the undef could be an SNaN, and fdiv is
2298not (currently) defined on SNaN's. However, in the second example, we can make
2299a more aggressive assumption: because the undef is allowed to be an arbitrary
2300value, we are allowed to assume that it could be zero. Since a divide by zero
Chris Lattner10ff0c12009-09-08 19:45:34 +0000[diff] [blame]2301has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2302does not execute at all. This allows us to delete the divide and all code after
2303it: since the undefined operation "can't happen", the optimizer can assume that
2304it occurs in dead code.
2305</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2306
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2307<div class="doc_code">
2308<pre>
2309a: store undef -> %X
2310b: store %X -> undef
2311Safe:
2312a: &lt;deleted&gt;
2313b: unreachable
2314</pre>
2315</div>
2316
2317<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2318can be assumed to not have any effect: we can assume that the value is
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2319overwritten with bits that happen to match what was already there. However, a
2320store "to" an undefined location could clobber arbitrary memory, therefore, it
2321has undefined behavior.</p>
2322
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2323</div>
2324
2325<!-- ======================================================================= -->
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2326<div class="doc_subsection"><a name="trapvalues">Trap Values</a></div>
2327<div class="doc_text">
2328
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2329<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2330 instead of representing an unspecified bit pattern, they represent the
2331 fact that an instruction or constant expression which cannot evoke side
2332 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2333 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2334
Dan Gohman283a3502010-04-24 22:15:58 +0000[diff] [blame]2335<p>Any non-void instruction or constant expression other than a non-intrinsic
2336 call, invoke, or phi with a trap operand has trap as its result value.
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2337 Any instruction with a trap operand which may have side effects emits
2338 those side effects as if it had an undef operand instead.</p>
2339
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2340<p>If a <a href="#i_br"><tt>br</tt></a> or
2341 <a href="#i_switch"><tt>switch</tt></a> instruction has a trap value
2342 operand, all non-phi non-void instructions which control-depend on it
2343 have trap as their result value. If any instruction which
2344 control-depends on the <tt>br</tt> or <tt>switch</tt> invokes externally
2345 visible side effects, the behavior of the program is undefined.</p>
2346
2347<!-- FIXME: What about exceptions thrown from control-dependent instrs? -->
2348
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2349<p>For example, an <a href="#i_and"><tt>and</tt></a> of a trap value with
2350 zero still has a trap value result. Using that value as an index in a
2351 <a href="#i_getelementptr"><tt>getelementptr</tt></a> yields a trap
2352 result. Using that result as the address of a
2353 <a href="#i_store"><tt>store</tt></a> produces undefined behavior.</p>
2354
2355<p>There is currently no way of representing a trap constant in the IR; they
2356 only exist when produced by certain instructions, such as an
2357 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag
2358 set, when overflow occurs.</p>
2359
2360</div>
2361
2362<!-- ======================================================================= -->
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2363<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2364 Blocks</a></div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2365<div class="doc_text">
2366
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2367<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2368
2369<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2370 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2371 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2372
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2373<p>This value only has defined behavior when used as an operand to the
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2374 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2375 against null. Pointer equality tests between labels addresses is undefined
2376 behavior - though, again, comparison against null is ok, and no label is
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2377 equal to the null pointer. This may also be passed around as an opaque
2378 pointer sized value as long as the bits are not inspected. This allows
Chris Lattnerda37b302009-10-27 21:44:20 +0000[diff] [blame]2379 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2380 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2381
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2382<p>Finally, some targets may provide defined semantics when
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2383 using the value as the operand to an inline assembly, but that is target
2384 specific.
2385 </p>
2386
2387</div>
2388
2389
2390<!-- ======================================================================= -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2391<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2392</div>
2393
2394<div class="doc_text">
2395
2396<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2397 to be used as constants. Constant expressions may be of
2398 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2399 operation that does not have side effects (e.g. load and call are not
2400 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2401
2402<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2403 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2404 <dd>Truncate a constant to another type. The bit size of CST must be larger
2405 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2406
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2407 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2408 <dd>Zero extend a constant to another type. The bit size of CST must be
2409 smaller or equal to the bit size of TYPE. Both types must be
2410 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2411
2412 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2413 <dd>Sign extend a constant to another type. The bit size of CST must be
2414 smaller or equal to the bit size of TYPE. Both types must be
2415 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2416
2417 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2418 <dd>Truncate a floating point constant to another floating point type. The
2419 size of CST must be larger than the size of TYPE. Both types must be
2420 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2421
2422 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2423 <dd>Floating point extend a constant to another type. The size of CST must be
2424 smaller or equal to the size of TYPE. Both types must be floating
2425 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2426
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]2427 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2428 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2429 constant. TYPE must be a scalar or vector integer type. CST must be of
2430 scalar or vector floating point type. Both CST and TYPE must be scalars,
2431 or vectors of the same number of elements. If the value won't fit in the
2432 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2433
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2434 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2435 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2436 constant. TYPE must be a scalar or vector integer type. CST must be of
2437 scalar or vector floating point type. Both CST and TYPE must be scalars,
2438 or vectors of the same number of elements. If the value won't fit in the
2439 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2440
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2441 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2442 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2443 constant. TYPE must be a scalar or vector floating point type. CST must be
2444 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2445 vectors of the same number of elements. If the value won't fit in the
2446 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2447
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2448 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2449 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2450 constant. TYPE must be a scalar or vector floating point type. CST must be
2451 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2452 vectors of the same number of elements. If the value won't fit in the
2453 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2454
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2455 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2456 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2457 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2458 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2459 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2460
2461 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2462 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2463 type. CST must be of integer type. The CST value is zero extended,
2464 truncated, or unchanged to make it fit in a pointer size. This one is
2465 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2466
2467 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2468 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2469 are the same as those for the <a href="#i_bitcast">bitcast
2470 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2471
2472 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]2473 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2474 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2475 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2476 instruction, the index list may have zero or more indexes, which are
2477 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2478
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2479 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2480 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2481
2482 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2483 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2484
2485 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2486 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2487
2488 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2489 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2490 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2491
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]2492 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2493 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2494 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2495
2496 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2497 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2498 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2499
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2500 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2501 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2502 be any of the <a href="#binaryops">binary</a>
2503 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2504 on operands are the same as those for the corresponding instruction
2505 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2506</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2507
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2508</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2509
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2510<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2511<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2512<!-- *********************************************************************** -->
2513
2514<!-- ======================================================================= -->
2515<div class="doc_subsection">
2516<a name="inlineasm">Inline Assembler Expressions</a>
2517</div>
2518
2519<div class="doc_text">
2520
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2521<p>LLVM supports inline assembler expressions (as opposed
2522 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2523 a special value. This value represents the inline assembler as a string
2524 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2525 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2526 expression has side effects, and a flag indicating whether the function
2527 containing the asm needs to align its stack conservatively. An example
2528 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2529
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2530<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2531<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2532i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2533</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2534</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2535
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2536<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2537 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2538 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2539
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2540<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2541<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2542%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]2543</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2544</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2545
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2546<p>Inline asms with side effects not visible in the constraint list must be
2547 marked as having side effects. This is done through the use of the
2548 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2549
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2550<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2551<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2552call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2553</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2554</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2555
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2556<p>In some cases inline asms will contain code that will not work unless the
2557 stack is aligned in some way, such as calls or SSE instructions on x86,
2558 yet will not contain code that does that alignment within the asm.
2559 The compiler should make conservative assumptions about what the asm might
2560 contain and should generate its usual stack alignment code in the prologue
2561 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2562
2563<div class="doc_code">
2564<pre>
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2565call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2566</pre>
2567</div>
2568
2569<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2570 first.</p>
2571
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2572<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2573 documented here. Constraints on what can be done (e.g. duplication, moving,
2574 etc need to be documented). This is probably best done by reference to
2575 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2576</div>
2577
2578<div class="doc_subsubsection">
2579<a name="inlineasm_md">Inline Asm Metadata</a>
2580</div>
2581
2582<div class="doc_text">
2583
2584<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
2585 attached to it that contains a constant integer. If present, the code
2586 generator will use the integer as the location cookie value when report
2587 errors through the LLVMContext error reporting mechanisms. This allows a
2588 front-end to corrolate backend errors that occur with inline asm back to the
2589 source code that produced it. For example:</p>
2590
2591<div class="doc_code">
2592<pre>
2593call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2594...
2595!42 = !{ i32 1234567 }
2596</pre>
2597</div>
2598
2599<p>It is up to the front-end to make sense of the magic numbers it places in the
2600 IR.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2601
2602</div>
2603
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2604<!-- ======================================================================= -->
2605<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2606 Strings</a>
2607</div>
2608
2609<div class="doc_text">
2610
2611<p>LLVM IR allows metadata to be attached to instructions in the program that
2612 can convey extra information about the code to the optimizers and code
2613 generator. One example application of metadata is source-level debug
2614 information. There are two metadata primitives: strings and nodes. All
2615 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2616 preceding exclamation point ('<tt>!</tt>').</p>
2617
2618<p>A metadata string is a string surrounded by double quotes. It can contain
2619 any character by escaping non-printable characters with "\xx" where "xx" is
2620 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2621
2622<p>Metadata nodes are represented with notation similar to structure constants
2623 (a comma separated list of elements, surrounded by braces and preceded by an
2624 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2625 10}</tt>". Metadata nodes can have any values as their operand.</p>
2626
2627<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2628 metadata nodes, which can be looked up in the module symbol table. For
2629 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2630
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2631<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
2632 function is using two metadata arguments.
2633
2634 <div class="doc_code">
2635 <pre>
2636 call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2637 </pre>
2638 </div></p>
2639
2640<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
2641 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.
2642
2643 <div class="doc_code">
2644 <pre>
2645 %indvar.next = add i64 %indvar, 1, !dbg !21
2646 </pre>
2647 </div></p>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2648</div>
2649
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2650
2651<!-- *********************************************************************** -->
2652<div class="doc_section">
2653 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2654</div>
2655<!-- *********************************************************************** -->
2656
2657<p>LLVM has a number of "magic" global variables that contain data that affect
2658code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2659of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2660section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2661by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2662
2663<!-- ======================================================================= -->
2664<div class="doc_subsection">
2665<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2666</div>
2667
2668<div class="doc_text">
2669
2670<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2671href="#linkage_appending">appending linkage</a>. This array contains a list of
2672pointers to global variables and functions which may optionally have a pointer
2673cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2674
2675<pre>
2676 @X = global i8 4
2677 @Y = global i32 123
2678
2679 @llvm.used = appending global [2 x i8*] [
2680 i8* @X,
2681 i8* bitcast (i32* @Y to i8*)
2682 ], section "llvm.metadata"
2683</pre>
2684
2685<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2686compiler, assembler, and linker are required to treat the symbol as if there is
2687a reference to the global that it cannot see. For example, if a variable has
2688internal linkage and no references other than that from the <tt>@llvm.used</tt>
2689list, it cannot be deleted. This is commonly used to represent references from
2690inline asms and other things the compiler cannot "see", and corresponds to
2691"attribute((used))" in GNU C.</p>
2692
2693<p>On some targets, the code generator must emit a directive to the assembler or
2694object file to prevent the assembler and linker from molesting the symbol.</p>
2695
2696</div>
2697
2698<!-- ======================================================================= -->
2699<div class="doc_subsection">
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2700<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2701</div>
2702
2703<div class="doc_text">
2704
2705<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2706<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2707touching the symbol. On targets that support it, this allows an intelligent
2708linker to optimize references to the symbol without being impeded as it would be
2709by <tt>@llvm.used</tt>.</p>
2710
2711<p>This is a rare construct that should only be used in rare circumstances, and
2712should not be exposed to source languages.</p>
2713
2714</div>
2715
2716<!-- ======================================================================= -->
2717<div class="doc_subsection">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2718<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2719</div>
2720
2721<div class="doc_text">
2722
2723<p>TODO: Describe this.</p>
2724
2725</div>
2726
2727<!-- ======================================================================= -->
2728<div class="doc_subsection">
2729<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2730</div>
2731
2732<div class="doc_text">
2733
2734<p>TODO: Describe this.</p>
2735
2736</div>
2737
2738
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2739<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2740<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2741<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2742
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2743<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2744
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2745<p>The LLVM instruction set consists of several different classifications of
2746 instructions: <a href="#terminators">terminator
2747 instructions</a>, <a href="#binaryops">binary instructions</a>,
2748 <a href="#bitwiseops">bitwise binary instructions</a>,
2749 <a href="#memoryops">memory instructions</a>, and
2750 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2751
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2752</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2753
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2754<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2755<div class="doc_subsection"> <a name="terminators">Terminator
2756Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2757
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2758<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2759
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2760<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2761 in a program ends with a "Terminator" instruction, which indicates which
2762 block should be executed after the current block is finished. These
2763 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2764 control flow, not values (the one exception being the
2765 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2766
Duncan Sands626b0242010-04-15 20:35:54 +0000[diff] [blame]2767<p>There are seven different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2768 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2769 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2770 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2771 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2772 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2773 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2774 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2775
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2776</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2777
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2778<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2779<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2780Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2781
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2782<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2783
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2784<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2785<pre>
2786 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]2787 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2788</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2789
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2790<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2791<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2792 a value) from a function back to the caller.</p>
2793
2794<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2795 value and then causes control flow, and one that just causes control flow to
2796 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2797
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2798<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2799<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2800 return value. The type of the return value must be a
2801 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2802
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2803<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2804 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2805 value or a return value with a type that does not match its type, or if it
2806 has a void return type and contains a '<tt>ret</tt>' instruction with a
2807 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2808
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2809<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2810<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2811 the calling function's context. If the caller is a
2812 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2813 instruction after the call. If the caller was an
2814 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2815 the beginning of the "normal" destination block. If the instruction returns
2816 a value, that value shall set the call or invoke instruction's return
2817 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2818
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2819<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2820<pre>
2821 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2822 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2823 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]2824</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2825
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2826</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2827<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2828<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2829
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2830<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2831
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2832<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2833<pre>
2834 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]2835</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2836
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2837<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2838<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2839 different basic block in the current function. There are two forms of this
2840 instruction, corresponding to a conditional branch and an unconditional
2841 branch.</p>
2842
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2843<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2844<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2845 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2846 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2847 target.</p>
2848
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2849<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2850<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2851 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2852 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2853 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2854
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2855<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2856<pre>
2857Test:
2858 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2859 br i1 %cond, label %IfEqual, label %IfUnequal
2860IfEqual:
2861 <a href="#i_ret">ret</a> i32 1
2862IfUnequal:
2863 <a href="#i_ret">ret</a> i32 0
2864</pre>
2865
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2866</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2867
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2868<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2869<div class="doc_subsubsection">
2870 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2871</div>
2872
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2873<div class="doc_text">
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2874
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2875<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2876<pre>
2877 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2878</pre>
2879
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2880<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2881<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]2882 several different places. It is a generalization of the '<tt>br</tt>'
2883 instruction, allowing a branch to occur to one of many possible
2884 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2885
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2886<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2887<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2888 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2889 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2890 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2891
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2892<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2893<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2894 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2895 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2896 transferred to the corresponding destination; otherwise, control flow is
2897 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2898
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2899<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2900<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2901 <tt>switch</tt> instruction, this instruction may be code generated in
2902 different ways. For example, it could be generated as a series of chained
2903 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2904
2905<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2906<pre>
2907 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2908 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2909 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2910
2911 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2912 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2913
2914 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2915 switch i32 %val, label %otherwise [ i32 0, label %onzero
2916 i32 1, label %onone
2917 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2918</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2919
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2920</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2921
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2922
2923<!-- _______________________________________________________________________ -->
2924<div class="doc_subsubsection">
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2925 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2926</div>
2927
2928<div class="doc_text">
2929
2930<h5>Syntax:</h5>
2931<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2932 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]2933</pre>
2934
2935<h5>Overview:</h5>
2936
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2937<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2938 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2939 "<tt>address</tt>". Address must be derived from a <a
2940 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2941
2942<h5>Arguments:</h5>
2943
2944<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2945 rest of the arguments indicate the full set of possible destinations that the
2946 address may point to. Blocks are allowed to occur multiple times in the
2947 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2948
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2949<p>This destination list is required so that dataflow analysis has an accurate
2950 understanding of the CFG.</p>
2951
2952<h5>Semantics:</h5>
2953
2954<p>Control transfers to the block specified in the address argument. All
2955 possible destination blocks must be listed in the label list, otherwise this
2956 instruction has undefined behavior. This implies that jumps to labels
2957 defined in other functions have undefined behavior as well.</p>
2958
2959<h5>Implementation:</h5>
2960
2961<p>This is typically implemented with a jump through a register.</p>
2962
2963<h5>Example:</h5>
2964<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2965 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2966</pre>
2967
2968</div>
2969
2970
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2971<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2972<div class="doc_subsubsection">
2973 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2974</div>
2975
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2976<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2977
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2978<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2979<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2980 &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]2981 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2982</pre>
2983
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2984<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2985<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2986 function, with the possibility of control flow transfer to either the
2987 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2988 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2989 control flow will return to the "normal" label. If the callee (or any
2990 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2991 instruction, control is interrupted and continued at the dynamically nearest
2992 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2993
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2994<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2995<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2996
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2997<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2998 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2999 convention</a> the call should use. If none is specified, the call
3000 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3001
3002 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3003 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3004 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3005
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3006 <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]3007 function value being invoked. In most cases, this is a direct function
3008 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3009 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3010
3011 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3012 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3013
3014 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3015 signature argument types and parameter attributes. All arguments must be
3016 of <a href="#t_firstclass">first class</a> type. If the function
3017 signature indicates the function accepts a variable number of arguments,
3018 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3019
3020 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3021 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3022
3023 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3024 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3025
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3026 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3027 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3028 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3029</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3030
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3031<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3032<p>This instruction is designed to operate as a standard
3033 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3034 primary difference is that it establishes an association with a label, which
3035 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3036
3037<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3038 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3039 exception. Additionally, this is important for implementation of
3040 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3041
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3042<p>For the purposes of the SSA form, the definition of the value returned by the
3043 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3044 block to the "normal" label. If the callee unwinds then no return value is
3045 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3046
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3047<p>Note that the code generator does not yet completely support unwind, and
3048that the invoke/unwind semantics are likely to change in future versions.</p>
3049
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3050<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3051<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3052 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3053 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3054 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3055 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3056</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3057
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3058</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3059
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3060<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3061
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3062<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
3063Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3064
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3065<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3066
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3067<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3068<pre>
3069 unwind
3070</pre>
3071
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3072<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3073<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3074 at the first callee in the dynamic call stack which used
3075 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3076 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3077
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3078<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3079<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3080 immediately halt. The dynamic call stack is then searched for the
3081 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3082 Once found, execution continues at the "exceptional" destination block
3083 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3084 instruction in the dynamic call chain, undefined behavior results.</p>
3085
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3086<p>Note that the code generator does not yet completely support unwind, and
3087that the invoke/unwind semantics are likely to change in future versions.</p>
3088
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3089</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3090
3091<!-- _______________________________________________________________________ -->
3092
3093<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
3094Instruction</a> </div>
3095
3096<div class="doc_text">
3097
3098<h5>Syntax:</h5>
3099<pre>
3100 unreachable
3101</pre>
3102
3103<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3104<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3105 instruction is used to inform the optimizer that a particular portion of the
3106 code is not reachable. This can be used to indicate that the code after a
3107 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3108
3109<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3110<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3111
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3112</div>
3113
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3114<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3115<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3116
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3117<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3118
3119<p>Binary operators are used to do most of the computation in a program. They
3120 require two operands of the same type, execute an operation on them, and
3121 produce a single value. The operands might represent multiple data, as is
3122 the case with the <a href="#t_vector">vector</a> data type. The result value
3123 has the same type as its operands.</p>
3124
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3125<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3126
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3127</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3128
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3129<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3130<div class="doc_subsubsection">
3131 <a name="i_add">'<tt>add</tt>' Instruction</a>
3132</div>
3133
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3134<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3135
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3136<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3137<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3138 &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]3139 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3140 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3141 &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]3142</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3143
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3144<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3145<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3146
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3147<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3148<p>The two arguments to the '<tt>add</tt>' instruction must
3149 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3150 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3151
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3152<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3153<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3154
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3155<p>If the sum has unsigned overflow, the result returned is the mathematical
3156 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]3157
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3158<p>Because LLVM integers use a two's complement representation, this instruction
3159 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3160
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3161<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3162 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3163 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3164 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3165 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3166
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3167<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3168<pre>
3169 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3170</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3171
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3172</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3173
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3174<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3175<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3176 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
3177</div>
3178
3179<div class="doc_text">
3180
3181<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3182<pre>
3183 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3184</pre>
3185
3186<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3187<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3188
3189<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3190<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3191 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3192 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3193
3194<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3195<p>The value produced is the floating point sum of the two operands.</p>
3196
3197<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3198<pre>
3199 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3200</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3201
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3202</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3203
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3204<!-- _______________________________________________________________________ -->
3205<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3206 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
3207</div>
3208
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3209<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3210
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3211<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3212<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3213 &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]3214 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3215 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3216 &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]3217</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3218
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3219<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3220<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3221 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3222
3223<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3224 '<tt>neg</tt>' instruction present in most other intermediate
3225 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3226
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3227<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3228<p>The two arguments to the '<tt>sub</tt>' instruction must
3229 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3230 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3231
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3232<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3233<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3234
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3235<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3236 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3237 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3238
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3239<p>Because LLVM integers use a two's complement representation, this instruction
3240 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3241
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3242<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3243 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3244 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3245 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3246 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3247
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3248<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3249<pre>
3250 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3251 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3252</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3253
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3254</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3255
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3256<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3257<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3258 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3259</div>
3260
3261<div class="doc_text">
3262
3263<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3264<pre>
3265 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3266</pre>
3267
3268<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3269<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3270 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3271
3272<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3273 '<tt>fneg</tt>' instruction present in most other intermediate
3274 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3275
3276<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3277<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3278 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3279 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3280
3281<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3282<p>The value produced is the floating point difference of the two operands.</p>
3283
3284<h5>Example:</h5>
3285<pre>
3286 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3287 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3288</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3289
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3290</div>
3291
3292<!-- _______________________________________________________________________ -->
3293<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3294 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3295</div>
3296
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3297<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3298
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3299<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3300<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3301 &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]3302 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3303 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3304 &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]3305</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3306
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3307<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3308<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3309
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3310<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3311<p>The two arguments to the '<tt>mul</tt>' instruction must
3312 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3313 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3314
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3315<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3316<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3317
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3318<p>If the result of the multiplication has unsigned overflow, the result
3319 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3320 width of the result.</p>
3321
3322<p>Because LLVM integers use a two's complement representation, and the result
3323 is the same width as the operands, this instruction returns the correct
3324 result for both signed and unsigned integers. If a full product
3325 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3326 be sign-extended or zero-extended as appropriate to the width of the full
3327 product.</p>
3328
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3329<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3330 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3331 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3332 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3333 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3334
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3335<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3336<pre>
3337 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3338</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3339
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3340</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3341
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3342<!-- _______________________________________________________________________ -->
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3343<div class="doc_subsubsection">
3344 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3345</div>
3346
3347<div class="doc_text">
3348
3349<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3350<pre>
3351 &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]3352</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3353
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3354<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3355<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3356
3357<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3358<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3359 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3360 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3361
3362<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3363<p>The value produced is the floating point product of the two operands.</p>
3364
3365<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3366<pre>
3367 &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]3368</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3369
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3370</div>
3371
3372<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3373<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3374</a></div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3375
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3376<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3377
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3378<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3379<pre>
3380 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3381</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3382
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3383<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3384<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3385
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3386<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3387<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3388 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3389 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3390
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3391<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3392<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3393
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3394<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3395 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3396
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3397<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3398
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3399<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3400<pre>
3401 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3402</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3403
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3404</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3405
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3406<!-- _______________________________________________________________________ -->
3407<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3408</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3409
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3410<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3411
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3412<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3413<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3414 &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]3415 &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]3416</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3417
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3418<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3419<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3420
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3421<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3422<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3423 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3424 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3425
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3426<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3427<p>The value produced is the signed integer quotient of the two operands rounded
3428 towards zero.</p>
3429
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3430<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3431 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3432
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3433<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3434 undefined behavior; this is a rare case, but can occur, for example, by doing
3435 a 32-bit division of -2147483648 by -1.</p>
3436
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3437<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3438 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
3439 be rounded or if overflow would occur.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3440
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3441<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3442<pre>
3443 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3444</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3445
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3446</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3447
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3448<!-- _______________________________________________________________________ -->
3449<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3450Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3451
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3452<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3453
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3454<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3455<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3456 &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]3457</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3458
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3459<h5>Overview:</h5>
3460<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3461
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3462<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3463<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3464 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3465 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3466
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3467<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3468<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3469
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3470<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3471<pre>
3472 &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]3473</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3474
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3475</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3476
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3477<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3478<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3479</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3480
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3481<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3482
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3483<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3484<pre>
3485 &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]3486</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3487
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3488<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3489<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3490 division of its two arguments.</p>
3491
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3492<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3493<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3494 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3495 values. Both arguments must have identical types.</p>
3496
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3497<h5>Semantics:</h5>
3498<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3499 This instruction always performs an unsigned division to get the
3500 remainder.</p>
3501
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3502<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3503 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3504
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3505<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3506
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3507<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3508<pre>
3509 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3510</pre>
3511
3512</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3513
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3514<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3515<div class="doc_subsubsection">
3516 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3517</div>
3518
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3519<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3520
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3521<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3522<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3523 &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]3524</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3525
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3526<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3527<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3528 division of its two operands. This instruction can also take
3529 <a href="#t_vector">vector</a> versions of the values in which case the
3530 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3531
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3532<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3533<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3534 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3535 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3536
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3537<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3538<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3539 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3540 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3541 a value. For more information about the difference,
3542 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3543 Math Forum</a>. For a table of how this is implemented in various languages,
3544 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3545 Wikipedia: modulo operation</a>.</p>
3546
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3547<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3548 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3549
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3550<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3551 Overflow also leads to undefined behavior; this is a rare case, but can
3552 occur, for example, by taking the remainder of a 32-bit division of
3553 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3554 lets srem be implemented using instructions that return both the result of
3555 the division and the remainder.)</p>
3556
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3557<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3558<pre>
3559 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3560</pre>
3561
3562</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3563
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3564<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3565<div class="doc_subsubsection">
3566 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3567
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3568<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3569
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3570<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3571<pre>
3572 &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]3573</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3574
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3575<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3576<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3577 its two operands.</p>
3578
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3579<h5>Arguments:</h5>
3580<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3581 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3582 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3583
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3584<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3585<p>This instruction returns the <i>remainder</i> of a division. The remainder
3586 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3587
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3588<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3589<pre>
3590 &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]3591</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3592
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3593</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3594
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3595<!-- ======================================================================= -->
3596<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3597Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3598
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3599<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3600
3601<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3602 program. They are generally very efficient instructions and can commonly be
3603 strength reduced from other instructions. They require two operands of the
3604 same type, execute an operation on them, and produce a single value. The
3605 resulting value is the same type as its operands.</p>
3606
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3607</div>
3608
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3609<!-- _______________________________________________________________________ -->
3610<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3611Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3612
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3613<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3614
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3615<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3616<pre>
3617 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3618</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3619
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3620<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3621<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3622 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3623
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3624<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3625<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3626 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3627 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3628
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3629<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3630<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3631 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3632 is (statically or dynamically) negative or equal to or larger than the number
3633 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3634 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3635 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3636
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3637<h5>Example:</h5>
3638<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3639 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3640 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3641 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3642 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3643 &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]3644</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3645
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3646</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3647
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3648<!-- _______________________________________________________________________ -->
3649<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3650Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3651
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3652<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3653
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3654<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3655<pre>
3656 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3657</pre>
3658
3659<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3660<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3661 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3662
3663<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3664<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3665 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3666 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3667
3668<h5>Semantics:</h5>
3669<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3670 significant bits of the result will be filled with zero bits after the shift.
3671 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3672 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3673 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3674 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3675
3676<h5>Example:</h5>
3677<pre>
3678 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3679 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3680 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3681 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3682 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3683 &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]3684</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3685
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3686</div>
3687
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3688<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3689<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3690Instruction</a> </div>
3691<div class="doc_text">
3692
3693<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3694<pre>
3695 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3696</pre>
3697
3698<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3699<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3700 operand shifted to the right a specified number of bits with sign
3701 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3702
3703<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3704<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3705 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3706 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3707
3708<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3709<p>This instruction always performs an arithmetic shift right operation, The
3710 most significant bits of the result will be filled with the sign bit
3711 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3712 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3713 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3714 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3715
3716<h5>Example:</h5>
3717<pre>
3718 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3719 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3720 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3721 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3722 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3723 &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]3724</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3725
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3726</div>
3727
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3728<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3729<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3730Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3731
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3732<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3733
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3734<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3735<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3736 &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]3737</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3738
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3739<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3740<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3741 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3742
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3743<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3744<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3745 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3746 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3747
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3748<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3749<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3750
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3751<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3752 <tbody>
3753 <tr>
3754 <td>In0</td>
3755 <td>In1</td>
3756 <td>Out</td>
3757 </tr>
3758 <tr>
3759 <td>0</td>
3760 <td>0</td>
3761 <td>0</td>
3762 </tr>
3763 <tr>
3764 <td>0</td>
3765 <td>1</td>
3766 <td>0</td>
3767 </tr>
3768 <tr>
3769 <td>1</td>
3770 <td>0</td>
3771 <td>0</td>
3772 </tr>
3773 <tr>
3774 <td>1</td>
3775 <td>1</td>
3776 <td>1</td>
3777 </tr>
3778 </tbody>
3779</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3780
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3781<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3782<pre>
3783 &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]3784 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3785 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3786</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3787</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3788<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3789<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3790
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3791<div class="doc_text">
3792
3793<h5>Syntax:</h5>
3794<pre>
3795 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3796</pre>
3797
3798<h5>Overview:</h5>
3799<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3800 two operands.</p>
3801
3802<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3803<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3804 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3805 values. Both arguments must have identical types.</p>
3806
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3807<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3808<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3809
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3810<table border="1" cellspacing="0" cellpadding="4">
3811 <tbody>
3812 <tr>
3813 <td>In0</td>
3814 <td>In1</td>
3815 <td>Out</td>
3816 </tr>
3817 <tr>
3818 <td>0</td>
3819 <td>0</td>
3820 <td>0</td>
3821 </tr>
3822 <tr>
3823 <td>0</td>
3824 <td>1</td>
3825 <td>1</td>
3826 </tr>
3827 <tr>
3828 <td>1</td>
3829 <td>0</td>
3830 <td>1</td>
3831 </tr>
3832 <tr>
3833 <td>1</td>
3834 <td>1</td>
3835 <td>1</td>
3836 </tr>
3837 </tbody>
3838</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3839
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3840<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3841<pre>
3842 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3843 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3844 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3845</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3846
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3847</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3848
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3849<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3850<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3851Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3852
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3853<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3854
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3855<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3856<pre>
3857 &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]3858</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3859
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3860<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3861<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3862 its two operands. The <tt>xor</tt> is used to implement the "one's
3863 complement" operation, which is the "~" operator in C.</p>
3864
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3865<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3866<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3867 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3868 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3869
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3870<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3871<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3872
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3873<table border="1" cellspacing="0" cellpadding="4">
3874 <tbody>
3875 <tr>
3876 <td>In0</td>
3877 <td>In1</td>
3878 <td>Out</td>
3879 </tr>
3880 <tr>
3881 <td>0</td>
3882 <td>0</td>
3883 <td>0</td>
3884 </tr>
3885 <tr>
3886 <td>0</td>
3887 <td>1</td>
3888 <td>1</td>
3889 </tr>
3890 <tr>
3891 <td>1</td>
3892 <td>0</td>
3893 <td>1</td>
3894 </tr>
3895 <tr>
3896 <td>1</td>
3897 <td>1</td>
3898 <td>0</td>
3899 </tr>
3900 </tbody>
3901</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3902
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3903<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3904<pre>
3905 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3906 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3907 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3908 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3909</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3910
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3911</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3912
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3913<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3914<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3915 <a name="vectorops">Vector Operations</a>
3916</div>
3917
3918<div class="doc_text">
3919
3920<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3921 target-independent manner. These instructions cover the element-access and
3922 vector-specific operations needed to process vectors effectively. While LLVM
3923 does directly support these vector operations, many sophisticated algorithms
3924 will want to use target-specific intrinsics to take full advantage of a
3925 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3926
3927</div>
3928
3929<!-- _______________________________________________________________________ -->
3930<div class="doc_subsubsection">
3931 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3932</div>
3933
3934<div class="doc_text">
3935
3936<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3937<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3938 &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]3939</pre>
3940
3941<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3942<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3943 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3944
3945
3946<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3947<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3948 of <a href="#t_vector">vector</a> type. The second operand is an index
3949 indicating the position from which to extract the element. The index may be
3950 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3951
3952<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3953<p>The result is a scalar of the same type as the element type of
3954 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3955 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3956 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3957
3958<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3959<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3960 &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]3961</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3962
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3963</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3964
3965<!-- _______________________________________________________________________ -->
3966<div class="doc_subsubsection">
3967 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3968</div>
3969
3970<div class="doc_text">
3971
3972<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3973<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3974 &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]3975</pre>
3976
3977<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3978<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3979 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3980
3981<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3982<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3983 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3984 whose type must equal the element type of the first operand. The third
3985 operand is an index indicating the position at which to insert the value.
3986 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3987
3988<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3989<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3990 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3991 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3992 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3993
3994<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3995<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3996 &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]3997</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3998
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3999</div>
4000
4001<!-- _______________________________________________________________________ -->
4002<div class="doc_subsubsection">
4003 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
4004</div>
4005
4006<div class="doc_text">
4007
4008<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4009<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4010 &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]4011</pre>
4012
4013<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4014<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4015 from two input vectors, returning a vector with the same element type as the
4016 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4017
4018<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4019<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4020 with types that match each other. The third argument is a shuffle mask whose
4021 element type is always 'i32'. The result of the instruction is a vector
4022 whose length is the same as the shuffle mask and whose element type is the
4023 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4024
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4025<p>The shuffle mask operand is required to be a constant vector with either
4026 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4027
4028<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4029<p>The elements of the two input vectors are numbered from left to right across
4030 both of the vectors. The shuffle mask operand specifies, for each element of
4031 the result vector, which element of the two input vectors the result element
4032 gets. The element selector may be undef (meaning "don't care") and the
4033 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4034
4035<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4036<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4037 &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]4038 &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]4039 &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]4040 &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]4041 &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]4042 &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]4043 &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]4044 &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]4045</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4046
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4047</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4048
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4049<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4050<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4051 <a name="aggregateops">Aggregate Operations</a>
4052</div>
4053
4054<div class="doc_text">
4055
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4056<p>LLVM supports several instructions for working with
4057 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4058
4059</div>
4060
4061<!-- _______________________________________________________________________ -->
4062<div class="doc_subsubsection">
4063 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
4064</div>
4065
4066<div class="doc_text">
4067
4068<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4069<pre>
4070 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4071</pre>
4072
4073<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4074<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4075 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4076
4077<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4078<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4079 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4080 <a href="#t_array">array</a> type. The operands are constant indices to
4081 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4082 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4083
4084<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4085<p>The result is the value at the position in the aggregate specified by the
4086 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4087
4088<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4089<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4090 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4091</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4092
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4093</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4094
4095<!-- _______________________________________________________________________ -->
4096<div class="doc_subsubsection">
4097 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
4098</div>
4099
4100<div class="doc_text">
4101
4102<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4103<pre>
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]4104 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt; <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4105</pre>
4106
4107<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4108<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4109 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4110
4111<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4112<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4113 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4114 <a href="#t_array">array</a> type. The second operand is a first-class
4115 value to insert. The following operands are constant indices indicating
4116 the position at which to insert the value in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4117 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
4118 value to insert must have the same type as the value identified by the
4119 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4120
4121<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4122<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4123 that of <tt>val</tt> except that the value at the position specified by the
4124 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4125
4126<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4127<pre>
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]4128 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4129 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4130</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4131
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4132</div>
4133
4134
4135<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4136<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4137 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4138</div>
4139
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4140<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4141
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4142<p>A key design point of an SSA-based representation is how it represents
4143 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4144 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4145 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4146
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4147</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4148
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4149<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4150<div class="doc_subsubsection">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4151 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
4152</div>
4153
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4154<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4155
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4156<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4157<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4158 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4159</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4160
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4161<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4162<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4163 currently executing function, to be automatically released when this function
4164 returns to its caller. The object is always allocated in the generic address
4165 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4166
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4167<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4168<p>The '<tt>alloca</tt>' instruction
4169 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4170 runtime stack, returning a pointer of the appropriate type to the program.
4171 If "NumElements" is specified, it is the number of elements allocated,
4172 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4173 specified, the value result of the allocation is guaranteed to be aligned to
4174 at least that boundary. If not specified, or if zero, the target can choose
4175 to align the allocation on any convenient boundary compatible with the
4176 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4177
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4178<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4179
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4180<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4181<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4182 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4183 memory is automatically released when the function returns. The
4184 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4185 variables that must have an address available. When the function returns
4186 (either with the <tt><a href="#i_ret">ret</a></tt>
4187 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4188 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4189
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4190<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4191<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4192 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4193 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4194 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4195 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4196</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4197
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4198</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4199
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4200<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4201<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
4202Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4203
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4204<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4205
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4206<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4207<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4208 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4209 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4210 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4211</pre>
4212
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4213<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4214<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4215
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4216<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4217<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4218 from which to load. The pointer must point to
4219 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4220 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame^]4221 number or order of execution of this <tt>load</tt> with other <a
4222 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4223
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4224<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4225 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]4226 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4227 alignment for the target. It is the responsibility of the code emitter to
4228 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4229 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4230 produce less efficient code. An alignment of 1 is always safe.</p>
4231
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4232<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4233 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4234 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4235 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4236 and code generator that this load is not expected to be reused in the cache.
4237 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4238 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4239
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4240<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4241<p>The location of memory pointed to is loaded. If the value being loaded is of
4242 scalar type then the number of bytes read does not exceed the minimum number
4243 of bytes needed to hold all bits of the type. For example, loading an
4244 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4245 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4246 is undefined if the value was not originally written using a store of the
4247 same type.</p>
4248
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4249<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4250<pre>
4251 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4252 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4253 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4254</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4255
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4256</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4257
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4258<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4259<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4260Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4261
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]4262<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4263
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4264<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4265<pre>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4266 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
4267 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4268</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4269
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4270<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4271<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4272
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4273<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4274<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4275 and an address at which to store it. The type of the
4276 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4277 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame^]4278 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4279 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4280 order of execution of this <tt>store</tt> with other <a
4281 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4282
4283<p>The optional constant "align" argument specifies the alignment of the
4284 operation (that is, the alignment of the memory address). A value of 0 or an
4285 omitted "align" argument means that the operation has the preferential
4286 alignment for the target. It is the responsibility of the code emitter to
4287 ensure that the alignment information is correct. Overestimating the
4288 alignment results in an undefined behavior. Underestimating the alignment may
4289 produce less efficient code. An alignment of 1 is always safe.</p>
4290
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4291<p>The optional !nontemporal metadata must reference a single metatadata
4292 name <index> corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4293 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4294 instruction tells the optimizer and code generator that this load is
4295 not expected to be reused in the cache. The code generator may
4296 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4297 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4298
4299
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4300<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4301<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4302 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4303 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4304 does not exceed the minimum number of bytes needed to hold all bits of the
4305 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4306 writing a value of a type like <tt>i20</tt> with a size that is not an
4307 integral number of bytes, it is unspecified what happens to the extra bits
4308 that do not belong to the type, but they will typically be overwritten.</p>
4309
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4310<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4311<pre>
4312 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4313 store i32 3, i32* %ptr <i>; yields {void}</i>
4314 %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]4315</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4316
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4317</div>
4318
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4319<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4320<div class="doc_subsubsection">
4321 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4322</div>
4323
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4324<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4325
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4326<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4327<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4328 &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]4329 &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]4330</pre>
4331
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4332<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4333<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4334 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4335 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4336
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4337<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4338<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4339 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4340 elements of the aggregate object are indexed. The interpretation of each
4341 index is dependent on the type being indexed into. The first index always
4342 indexes the pointer value given as the first argument, the second index
4343 indexes a value of the type pointed to (not necessarily the value directly
4344 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4345 indexed into must be a pointer value, subsequent types can be arrays,
4346 vectors, structs and unions. Note that subsequent types being indexed into
4347 can never be pointers, since that would require loading the pointer before
4348 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4349
4350<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4351 When indexing into a (optionally packed) structure or union, only <tt>i32</tt>
4352 integer <b>constants</b> are allowed. When indexing into an array, pointer
4353 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]4354 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4355
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4356<p>For example, let's consider a C code fragment and how it gets compiled to
4357 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4358
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4359<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4360<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4361struct RT {
4362 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4363 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4364 char C;
4365};
4366struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4367 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4368 double Y;
4369 struct RT Z;
4370};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4371
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4372int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4373 return &amp;s[1].Z.B[5][13];
4374}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4375</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4376</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4377
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4378<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4379
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4380<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4381<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4382%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4383%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4384
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4385define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4386entry:
4387 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4388 ret i32* %reg
4389}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4390</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4391</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4392
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4393<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4394<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]4395 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4396 }</tt>' type, a structure. The second index indexes into the third element
4397 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4398 i8 }</tt>' type, another structure. The third index indexes into the second
4399 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4400 array. The two dimensions of the array are subscripted into, yielding an
4401 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4402 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4403
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4404<p>Note that it is perfectly legal to index partially through a structure,
4405 returning a pointer to an inner element. Because of this, the LLVM code for
4406 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4407
4408<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4409 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4410 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4411 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4412 %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]4413 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4414 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4415 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4416 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4417</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4418
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4419<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4420 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4421 base pointer is not an <i>in bounds</i> address of an allocated object,
4422 or if any of the addresses that would be formed by successive addition of
4423 the offsets implied by the indices to the base address with infinitely
4424 precise arithmetic are not an <i>in bounds</i> address of that allocated
4425 object. The <i>in bounds</i> addresses for an allocated object are all
4426 the addresses that point into the object, plus the address one byte past
4427 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4428
4429<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4430 the base address with silently-wrapping two's complement arithmetic, and
4431 the result value of the <tt>getelementptr</tt> may be outside the object
4432 pointed to by the base pointer. The result value may not necessarily be
4433 used to access memory though, even if it happens to point into allocated
4434 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4435 section for more information.</p>
4436
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4437<p>The getelementptr instruction is often confusing. For some more insight into
4438 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4439
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4440<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4441<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4442 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4443 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4444 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4445 %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]4446 <i>; yields i8*:eptr</i>
4447 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4448 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4449 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4450</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4451
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4452</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4453
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4454<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4455<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4456</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4457
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4458<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4459
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4460<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4461 which all take a single operand and a type. They perform various bit
4462 conversions on the operand.</p>
4463
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4464</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4465
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4466<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4467<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4468 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4469</div>
4470<div class="doc_text">
4471
4472<h5>Syntax:</h5>
4473<pre>
4474 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4475</pre>
4476
4477<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4478<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4479 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4480
4481<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4482<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4483 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4484 size and type of the result, which must be
4485 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4486 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4487 allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4488
4489<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4490<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4491 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4492 source size must be larger than the destination size, <tt>trunc</tt> cannot
4493 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4494
4495<h5>Example:</h5>
4496<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4497 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4498 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4499 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4500</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4501
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4502</div>
4503
4504<!-- _______________________________________________________________________ -->
4505<div class="doc_subsubsection">
4506 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4507</div>
4508<div class="doc_text">
4509
4510<h5>Syntax:</h5>
4511<pre>
4512 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4513</pre>
4514
4515<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4516<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4517 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4518
4519
4520<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4521<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4522 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4523 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4524 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4525 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4526
4527<h5>Semantics:</h5>
4528<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]4529 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4530
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4531<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]4532
4533<h5>Example:</h5>
4534<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4535 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4536 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4537</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4538
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4539</div>
4540
4541<!-- _______________________________________________________________________ -->
4542<div class="doc_subsubsection">
4543 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4544</div>
4545<div class="doc_text">
4546
4547<h5>Syntax:</h5>
4548<pre>
4549 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4550</pre>
4551
4552<h5>Overview:</h5>
4553<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4554
4555<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4556<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4557 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4558 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4559 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4560 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4561
4562<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4563<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4564 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4565 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4566
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4567<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]4568
4569<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4570<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4571 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4572 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4573</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4574
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4575</div>
4576
4577<!-- _______________________________________________________________________ -->
4578<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4579 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4580</div>
4581
4582<div class="doc_text">
4583
4584<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4585<pre>
4586 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4587</pre>
4588
4589<h5>Overview:</h5>
4590<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4591 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4592
4593<h5>Arguments:</h5>
4594<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4595 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4596 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]4597 <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]4598 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4599
4600<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4601<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4602 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4603 <a href="#t_floating">floating point</a> type. If the value cannot fit
4604 within the destination type, <tt>ty2</tt>, then the results are
4605 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4606
4607<h5>Example:</h5>
4608<pre>
4609 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4610 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4611</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4612
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4613</div>
4614
4615<!-- _______________________________________________________________________ -->
4616<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4617 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4618</div>
4619<div class="doc_text">
4620
4621<h5>Syntax:</h5>
4622<pre>
4623 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4624</pre>
4625
4626<h5>Overview:</h5>
4627<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]4628 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4629
4630<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4631<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4632 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4633 a <a href="#t_floating">floating point</a> type to cast it to. The source
4634 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4635
4636<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4637<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4638 <a href="#t_floating">floating point</a> type to a larger
4639 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4640 used to make a <i>no-op cast</i> because it always changes bits. Use
4641 <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]4642
4643<h5>Example:</h5>
4644<pre>
4645 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4646 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4647</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4648
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4649</div>
4650
4651<!-- _______________________________________________________________________ -->
4652<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4653 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4654</div>
4655<div class="doc_text">
4656
4657<h5>Syntax:</h5>
4658<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4659 &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]4660</pre>
4661
4662<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4663<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4664 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4665
4666<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4667<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4668 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4669 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4670 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4671 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4672
4673<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4674<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4675 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4676 towards zero) unsigned integer value. If the value cannot fit
4677 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4678
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4679<h5>Example:</h5>
4680<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4681 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4682 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4683 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4684</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4685
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4686</div>
4687
4688<!-- _______________________________________________________________________ -->
4689<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4690 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4691</div>
4692<div class="doc_text">
4693
4694<h5>Syntax:</h5>
4695<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4696 &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]4697</pre>
4698
4699<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4700<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4701 <a href="#t_floating">floating point</a> <tt>value</tt> to
4702 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4703
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4704<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4705<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4706 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4707 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4708 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4709 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4710
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4711<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4712<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4713 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4714 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4715 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4716
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4717<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4718<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4719 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4720 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4721 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4722</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4723
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4724</div>
4725
4726<!-- _______________________________________________________________________ -->
4727<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4728 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4729</div>
4730<div class="doc_text">
4731
4732<h5>Syntax:</h5>
4733<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4734 &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]4735</pre>
4736
4737<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4738<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4739 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4740
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4741<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4742<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]4743 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4744 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4745 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4746 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4747
4748<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4749<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4750 integer quantity and converts it to the corresponding floating point
4751 value. If the value cannot fit in the floating point value, the results are
4752 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4753
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4754<h5>Example:</h5>
4755<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4756 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4757 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4758</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4759
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4760</div>
4761
4762<!-- _______________________________________________________________________ -->
4763<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4764 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4765</div>
4766<div class="doc_text">
4767
4768<h5>Syntax:</h5>
4769<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4770 &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]4771</pre>
4772
4773<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4774<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4775 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4776
4777<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4778<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]4779 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4780 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4781 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4782 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4783
4784<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4785<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4786 quantity and converts it to the corresponding floating point value. If the
4787 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4788
4789<h5>Example:</h5>
4790<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4791 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4792 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4793</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4794
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4795</div>
4796
4797<!-- _______________________________________________________________________ -->
4798<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4799 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4800</div>
4801<div class="doc_text">
4802
4803<h5>Syntax:</h5>
4804<pre>
4805 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4806</pre>
4807
4808<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4809<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4810 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4811
4812<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4813<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4814 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4815 <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]4816
4817<h5>Semantics:</h5>
4818<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4819 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4820 truncating or zero extending that value to the size of the integer type. If
4821 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4822 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4823 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4824 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4825
4826<h5>Example:</h5>
4827<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4828 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4829 %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]4830</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4831
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4832</div>
4833
4834<!-- _______________________________________________________________________ -->
4835<div class="doc_subsubsection">
4836 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4837</div>
4838<div class="doc_text">
4839
4840<h5>Syntax:</h5>
4841<pre>
4842 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4843</pre>
4844
4845<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4846<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4847 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4848
4849<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4850<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4851 value to cast, and a type to cast it to, which must be a
4852 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4853
4854<h5>Semantics:</h5>
4855<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4856 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4857 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4858 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4859 than the size of a pointer then a zero extension is done. If they are the
4860 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4861
4862<h5>Example:</h5>
4863<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4864 %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]4865 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4866 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4867</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4868
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4869</div>
4870
4871<!-- _______________________________________________________________________ -->
4872<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4873 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4874</div>
4875<div class="doc_text">
4876
4877<h5>Syntax:</h5>
4878<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4879 &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]4880</pre>
4881
4882<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4883<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4884 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4885
4886<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4887<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4888 non-aggregate first class value, and a type to cast it to, which must also be
4889 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4890 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4891 identical. If the source type is a pointer, the destination type must also be
4892 a pointer. This instruction supports bitwise conversion of vectors to
4893 integers and to vectors of other types (as long as they have the same
4894 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4895
4896<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4897<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4898 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4899 this conversion. The conversion is done as if the <tt>value</tt> had been
4900 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4901 be converted to other pointer types with this instruction. To convert
4902 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4903 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4904
4905<h5>Example:</h5>
4906<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4907 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4908 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4909 %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]4910</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4911
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4912</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4913
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4914<!-- ======================================================================= -->
4915<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4916
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4917<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4918
4919<p>The instructions in this category are the "miscellaneous" instructions, which
4920 defy better classification.</p>
4921
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4922</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4923
4924<!-- _______________________________________________________________________ -->
4925<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4926</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4927
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4928<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4929
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4930<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4931<pre>
4932 &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]4933</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4934
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4935<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4936<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4937 boolean values based on comparison of its two integer, integer vector, or
4938 pointer operands.</p>
4939
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4940<h5>Arguments:</h5>
4941<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4942 the condition code indicating the kind of comparison to perform. It is not a
4943 value, just a keyword. The possible condition code are:</p>
4944
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4945<ol>
4946 <li><tt>eq</tt>: equal</li>
4947 <li><tt>ne</tt>: not equal </li>
4948 <li><tt>ugt</tt>: unsigned greater than</li>
4949 <li><tt>uge</tt>: unsigned greater or equal</li>
4950 <li><tt>ult</tt>: unsigned less than</li>
4951 <li><tt>ule</tt>: unsigned less or equal</li>
4952 <li><tt>sgt</tt>: signed greater than</li>
4953 <li><tt>sge</tt>: signed greater or equal</li>
4954 <li><tt>slt</tt>: signed less than</li>
4955 <li><tt>sle</tt>: signed less or equal</li>
4956</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4957
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4958<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4959 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4960 typed. They must also be identical types.</p>
4961
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4962<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4963<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4964 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4965 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]4966 result, as follows:</p>
4967
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4968<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4969 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4970 <tt>false</tt> otherwise. No sign interpretation is necessary or
4971 performed.</li>
4972
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4973 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4974 <tt>false</tt> otherwise. No sign interpretation is necessary or
4975 performed.</li>
4976
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4977 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4978 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4979
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4980 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4981 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4982 to <tt>op2</tt>.</li>
4983
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4984 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4985 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4986
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4987 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4988 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4989
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4990 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4991 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4992
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4993 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4994 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4995 to <tt>op2</tt>.</li>
4996
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4997 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4998 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4999
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5000 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5001 <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]5002</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5003
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5004<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5005 values are compared as if they were integers.</p>
5006
5007<p>If the operands are integer vectors, then they are compared element by
5008 element. The result is an <tt>i1</tt> vector with the same number of elements
5009 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5010
5011<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5012<pre>
5013 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5014 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5015 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5016 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5017 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5018 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5019</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5020
5021<p>Note that the code generator does not yet support vector types with
5022 the <tt>icmp</tt> instruction.</p>
5023
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5024</div>
5025
5026<!-- _______________________________________________________________________ -->
5027<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5028</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5029
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5030<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5031
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5032<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5033<pre>
5034 &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]5035</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5036
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5037<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5038<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5039 values based on comparison of its operands.</p>
5040
5041<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]5042(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5043
5044<p>If the operands are floating point vectors, then the result type is a vector
5045 of boolean with the same number of elements as the operands being
5046 compared.</p>
5047
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5048<h5>Arguments:</h5>
5049<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5050 the condition code indicating the kind of comparison to perform. It is not a
5051 value, just a keyword. The possible condition code are:</p>
5052
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5053<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5054 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5055 <li><tt>oeq</tt>: ordered and equal</li>
5056 <li><tt>ogt</tt>: ordered and greater than </li>
5057 <li><tt>oge</tt>: ordered and greater than or equal</li>
5058 <li><tt>olt</tt>: ordered and less than </li>
5059 <li><tt>ole</tt>: ordered and less than or equal</li>
5060 <li><tt>one</tt>: ordered and not equal</li>
5061 <li><tt>ord</tt>: ordered (no nans)</li>
5062 <li><tt>ueq</tt>: unordered or equal</li>
5063 <li><tt>ugt</tt>: unordered or greater than </li>
5064 <li><tt>uge</tt>: unordered or greater than or equal</li>
5065 <li><tt>ult</tt>: unordered or less than </li>
5066 <li><tt>ule</tt>: unordered or less than or equal</li>
5067 <li><tt>une</tt>: unordered or not equal</li>
5068 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5069 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5070</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5071
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5072<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5073 <i>unordered</i> means that either operand may be a QNAN.</p>
5074
5075<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5076 a <a href="#t_floating">floating point</a> type or
5077 a <a href="#t_vector">vector</a> of floating point type. They must have
5078 identical types.</p>
5079
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5080<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5081<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5082 according to the condition code given as <tt>cond</tt>. If the operands are
5083 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5084 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5085 follows:</p>
5086
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5087<ol>
5088 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5089
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5090 <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]5091 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5092
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5093 <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]5094 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5095
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5096 <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]5097 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5098
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5099 <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]5100 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5101
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5102 <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]5103 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5104
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5105 <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]5106 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5107
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5108 <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]5109
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5110 <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]5111 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5112
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5113 <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]5114 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5115
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5116 <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]5117 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5118
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5119 <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]5120 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5121
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5122 <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]5123 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5124
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5125 <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]5126 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5127
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5128 <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]5129
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5130 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5131</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5132
5133<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5134<pre>
5135 &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]5136 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5137 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5138 &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]5139</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5140
5141<p>Note that the code generator does not yet support vector types with
5142 the <tt>fcmp</tt> instruction.</p>
5143
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5144</div>
5145
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5146<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]5147<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5148 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
5149</div>
5150
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5151<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5152
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5153<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5154<pre>
5155 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5156</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5157
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5158<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5159<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5160 SSA graph representing the function.</p>
5161
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5162<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5163<p>The type of the incoming values is specified with the first type field. After
5164 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5165 one pair for each predecessor basic block of the current block. Only values
5166 of <a href="#t_firstclass">first class</a> type may be used as the value
5167 arguments to the PHI node. Only labels may be used as the label
5168 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5169
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5170<p>There must be no non-phi instructions between the start of a basic block and
5171 the PHI instructions: i.e. PHI instructions must be first in a basic
5172 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5173
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5174<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5175 occur on the edge from the corresponding predecessor block to the current
5176 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5177 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5178
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5179<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5180<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5181 specified by the pair corresponding to the predecessor basic block that
5182 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5183
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5184<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5185<pre>
5186Loop: ; Infinite loop that counts from 0 on up...
5187 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5188 %nextindvar = add i32 %indvar, 1
5189 br label %Loop
5190</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5191
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5192</div>
5193
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5194<!-- _______________________________________________________________________ -->
5195<div class="doc_subsubsection">
5196 <a name="i_select">'<tt>select</tt>' Instruction</a>
5197</div>
5198
5199<div class="doc_text">
5200
5201<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5202<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5203 &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>
5204
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5205 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5206</pre>
5207
5208<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5209<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5210 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5211
5212
5213<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5214<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5215 values indicating the condition, and two values of the
5216 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5217 vectors and the condition is a scalar, then entire vectors are selected, not
5218 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5219
5220<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5221<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5222 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5223
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5224<p>If the condition is a vector of i1, then the value arguments must be vectors
5225 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5226
5227<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5228<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5229 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5230</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5231
5232<p>Note that the code generator does not yet support conditions
5233 with vector type.</p>
5234
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5235</div>
5236
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5237<!-- _______________________________________________________________________ -->
5238<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5239 <a name="i_call">'<tt>call</tt>' Instruction</a>
5240</div>
5241
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5242<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5243
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5244<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5245<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5246 &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]5247</pre>
5248
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5249<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5250<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5251
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5252<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5253<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5254
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5255<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5256 <li>The optional "tail" marker indicates that the callee function does not
5257 access any allocas or varargs in the caller. Note that calls may be
5258 marked "tail" even if they do not occur before
5259 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5260 present, the function call is eligible for tail call optimization,
5261 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5262 optimized into a jump</a>. The code generator may optimize calls marked
5263 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5264 sibling call optimization</a> when the caller and callee have
5265 matching signatures, or 2) forced tail call optimization when the
5266 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5267 <ul>
5268 <li>Caller and callee both have the calling
5269 convention <tt>fastcc</tt>.</li>
5270 <li>The call is in tail position (ret immediately follows call and ret
5271 uses value of call or is void).</li>
5272 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5273 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5274 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5275 constraints are met.</a></li>
5276 </ul>
5277 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5278
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5279 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5280 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5281 defaults to using C calling conventions. The calling convention of the
5282 call must match the calling convention of the target function, or else the
5283 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5284
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5285 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5286 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5287 '<tt>inreg</tt>' attributes are valid here.</li>
5288
5289 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5290 type of the return value. Functions that return no value are marked
5291 <tt><a href="#t_void">void</a></tt>.</li>
5292
5293 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5294 being invoked. The argument types must match the types implied by this
5295 signature. This type can be omitted if the function is not varargs and if
5296 the function type does not return a pointer to a function.</li>
5297
5298 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5299 be invoked. In most cases, this is a direct function invocation, but
5300 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5301 to function value.</li>
5302
5303 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5304 signature argument types and parameter attributes. All arguments must be
5305 of <a href="#t_firstclass">first class</a> type. If the function
5306 signature indicates the function accepts a variable number of arguments,
5307 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5308
5309 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5310 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5311 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5312</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5313
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5314<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5315<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5316 a specified function, with its incoming arguments bound to the specified
5317 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5318 function, control flow continues with the instruction after the function
5319 call, and the return value of the function is bound to the result
5320 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5322<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5323<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5324 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5325 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5326 %X = tail call i32 @foo() <i>; yields i32</i>
5327 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5328 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5329
5330 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5331 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5332 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5333 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5334 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5335 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5336</pre>
5337
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5338<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5339standard C99 library as being the C99 library functions, and may perform
5340optimizations or generate code for them under that assumption. This is
5341something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5342freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5343
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5344</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5345
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5346<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5347<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5348 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5349</div>
5350
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5351<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5352
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5353<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5354<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5355 &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]5356</pre>
5357
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5358<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5359<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5360 the "variable argument" area of a function call. It is used to implement the
5361 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5362
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5363<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5364<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5365 argument. It returns a value of the specified argument type and increments
5366 the <tt>va_list</tt> to point to the next argument. The actual type
5367 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5368
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5369<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5370<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5371 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5372 to the next argument. For more information, see the variable argument
5373 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5374
5375<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]5376 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5377 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5378
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5379<p><tt>va_arg</tt> is an LLVM instruction instead of
5380 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5381 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5382
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5383<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5384<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5385
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5386<p>Note that the code generator does not yet fully support va_arg on many
5387 targets. Also, it does not currently support va_arg with aggregate types on
5388 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5389
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5390</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5391
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5392<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5393<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5394<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5395
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5396<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5397
5398<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5399 well known names and semantics and are required to follow certain
5400 restrictions. Overall, these intrinsics represent an extension mechanism for
5401 the LLVM language that does not require changing all of the transformations
5402 in LLVM when adding to the language (or the bitcode reader/writer, the
5403 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5404
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5405<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5406 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5407 begin with this prefix. Intrinsic functions must always be external
5408 functions: you cannot define the body of intrinsic functions. Intrinsic
5409 functions may only be used in call or invoke instructions: it is illegal to
5410 take the address of an intrinsic function. Additionally, because intrinsic
5411 functions are part of the LLVM language, it is required if any are added that
5412 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5413
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5414<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5415 family of functions that perform the same operation but on different data
5416 types. Because LLVM can represent over 8 million different integer types,
5417 overloading is used commonly to allow an intrinsic function to operate on any
5418 integer type. One or more of the argument types or the result type can be
5419 overloaded to accept any integer type. Argument types may also be defined as
5420 exactly matching a previous argument's type or the result type. This allows
5421 an intrinsic function which accepts multiple arguments, but needs all of them
5422 to be of the same type, to only be overloaded with respect to a single
5423 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5424
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5425<p>Overloaded intrinsics will have the names of its overloaded argument types
5426 encoded into its function name, each preceded by a period. Only those types
5427 which are overloaded result in a name suffix. Arguments whose type is matched
5428 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5429 can take an integer of any width and returns an integer of exactly the same
5430 integer width. This leads to a family of functions such as
5431 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5432 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5433 suffix is required. Because the argument's type is matched against the return
5434 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5435
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5436<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5437 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5438
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5439</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5440
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5441<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5442<div class="doc_subsection">
5443 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5444</div>
5445
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5446<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5447
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5448<p>Variable argument support is defined in LLVM with
5449 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5450 intrinsic functions. These functions are related to the similarly named
5451 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5452
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5453<p>All of these functions operate on arguments that use a target-specific value
5454 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5455 not define what this type is, so all transformations should be prepared to
5456 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5457
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5458<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]5459 instruction and the variable argument handling intrinsic functions are
5460 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5461
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5462<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5463<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5464define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5465 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5466 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5467 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5468 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5469
5470 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5471 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5472
5473 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5474 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5475 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5476 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5477 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5478
5479 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5480 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5481 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5482}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5483
5484declare void @llvm.va_start(i8*)
5485declare void @llvm.va_copy(i8*, i8*)
5486declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5487</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5488</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5489
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5490</div>
5491
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5492<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5493<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5494 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5495</div>
5496
5497
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5498<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5499
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5500<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5501<pre>
5502 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5503</pre>
5504
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5505<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5506<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5507 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]5508
5509<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5510<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]5511
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5512<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5513<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]5514 macro available in C. In a target-dependent way, it initializes
5515 the <tt>va_list</tt> element to which the argument points, so that the next
5516 call to <tt>va_arg</tt> will produce the first variable argument passed to
5517 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5518 need to know the last argument of the function as the compiler can figure
5519 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5520
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5521</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5522
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5523<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5524<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5525 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5526</div>
5527
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5528<div class="doc_text">
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5529
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5530<h5>Syntax:</h5>
5531<pre>
5532 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5533</pre>
5534
5535<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5536<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5537 which has been initialized previously
5538 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5539 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5540
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5541<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5542<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]5543
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5544<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5545<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]5546 macro available in C. In a target-dependent way, it destroys
5547 the <tt>va_list</tt> element to which the argument points. Calls
5548 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5549 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5550 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5551
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5552</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5553
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5554<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5555<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5556 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5557</div>
5558
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5559<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5560
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5561<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5562<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5563 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5564</pre>
5565
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5566<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5567<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5568 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5569
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5570<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5571<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]5572 The second argument is a pointer to a <tt>va_list</tt> element to copy
5573 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5574
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5575<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5576<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]5577 macro available in C. In a target-dependent way, it copies the
5578 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5579 element. This intrinsic is necessary because
5580 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5581 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5582
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5583</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5584
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5585<!-- ======================================================================= -->
5586<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5587 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5588</div>
5589
5590<div class="doc_text">
5591
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5592<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5593Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5594intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5595roots on the stack</a>, as well as garbage collector implementations that
5596require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5597barriers. Front-ends for type-safe garbage collected languages should generate
5598these intrinsics to make use of the LLVM garbage collectors. For more details,
5599see <a href="GarbageCollection.html">Accurate Garbage Collection with
5600LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5601
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5602<p>The garbage collection intrinsics only operate on objects in the generic
5603 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5604
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5605</div>
5606
5607<!-- _______________________________________________________________________ -->
5608<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5609 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5610</div>
5611
5612<div class="doc_text">
5613
5614<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5615<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5616 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5617</pre>
5618
5619<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5620<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]5621 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5622
5623<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5624<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5625 root pointer. The second pointer (which must be either a constant or a
5626 global value address) contains the meta-data to be associated with the
5627 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5628
5629<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5630<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]5631 location. At compile-time, the code generator generates information to allow
5632 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5633 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5634 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5635
5636</div>
5637
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5638<!-- _______________________________________________________________________ -->
5639<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5640 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5641</div>
5642
5643<div class="doc_text">
5644
5645<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5646<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5647 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5648</pre>
5649
5650<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5651<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5652 locations, allowing garbage collector implementations that require read
5653 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5654
5655<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5656<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]5657 allocated from the garbage collector. The first object is a pointer to the
5658 start of the referenced object, if needed by the language runtime (otherwise
5659 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5660
5661<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5662<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5663 instruction, but may be replaced with substantially more complex code by the
5664 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5665 may only be used in a function which <a href="#gc">specifies a GC
5666 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5667
5668</div>
5669
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5670<!-- _______________________________________________________________________ -->
5671<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5672 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5673</div>
5674
5675<div class="doc_text">
5676
5677<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5678<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5679 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5680</pre>
5681
5682<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5683<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5684 locations, allowing garbage collector implementations that require write
5685 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5686
5687<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5688<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]5689 object to store it to, and the third is the address of the field of Obj to
5690 store to. If the runtime does not require a pointer to the object, Obj may
5691 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5692
5693<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5694<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5695 instruction, but may be replaced with substantially more complex code by the
5696 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5697 may only be used in a function which <a href="#gc">specifies a GC
5698 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5699
5700</div>
5701
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5702<!-- ======================================================================= -->
5703<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5704 <a name="int_codegen">Code Generator Intrinsics</a>
5705</div>
5706
5707<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5708
5709<p>These intrinsics are provided by LLVM to expose special features that may
5710 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5711
5712</div>
5713
5714<!-- _______________________________________________________________________ -->
5715<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5716 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5717</div>
5718
5719<div class="doc_text">
5720
5721<h5>Syntax:</h5>
5722<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5723 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5724</pre>
5725
5726<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5727<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5728 target-specific value indicating the return address of the current function
5729 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5730
5731<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5732<p>The argument to this intrinsic indicates which function to return the address
5733 for. Zero indicates the calling function, one indicates its caller, etc.
5734 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5735
5736<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5737<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5738 indicating the return address of the specified call frame, or zero if it
5739 cannot be identified. The value returned by this intrinsic is likely to be
5740 incorrect or 0 for arguments other than zero, so it should only be used for
5741 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5742
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5743<p>Note that calling this intrinsic does not prevent function inlining or other
5744 aggressive transformations, so the value returned may not be that of the
5745 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5746
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5747</div>
5748
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5749<!-- _______________________________________________________________________ -->
5750<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5751 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5752</div>
5753
5754<div class="doc_text">
5755
5756<h5>Syntax:</h5>
5757<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5758 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5759</pre>
5760
5761<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5762<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5763 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5764
5765<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5766<p>The argument to this intrinsic indicates which function to return the frame
5767 pointer for. Zero indicates the calling function, one indicates its caller,
5768 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5769
5770<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5771<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5772 indicating the frame address of the specified call frame, or zero if it
5773 cannot be identified. The value returned by this intrinsic is likely to be
5774 incorrect or 0 for arguments other than zero, so it should only be used for
5775 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5776
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5777<p>Note that calling this intrinsic does not prevent function inlining or other
5778 aggressive transformations, so the value returned may not be that of the
5779 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5780
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5781</div>
5782
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5783<!-- _______________________________________________________________________ -->
5784<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5785 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5786</div>
5787
5788<div class="doc_text">
5789
5790<h5>Syntax:</h5>
5791<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5792 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5793</pre>
5794
5795<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5796<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5797 of the function stack, for use
5798 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5799 useful for implementing language features like scoped automatic variable
5800 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5801
5802<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5803<p>This intrinsic returns a opaque pointer value that can be passed
5804 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5805 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5806 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5807 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5808 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5809 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5810
5811</div>
5812
5813<!-- _______________________________________________________________________ -->
5814<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5815 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5816</div>
5817
5818<div class="doc_text">
5819
5820<h5>Syntax:</h5>
5821<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5822 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5823</pre>
5824
5825<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5826<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5827 the function stack to the state it was in when the
5828 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5829 executed. This is useful for implementing language features like scoped
5830 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5831
5832<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5833<p>See the description
5834 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5835
5836</div>
5837
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5838<!-- _______________________________________________________________________ -->
5839<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5840 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5841</div>
5842
5843<div class="doc_text">
5844
5845<h5>Syntax:</h5>
5846<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5847 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5848</pre>
5849
5850<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5851<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5852 insert a prefetch instruction if supported; otherwise, it is a noop.
5853 Prefetches have no effect on the behavior of the program but can change its
5854 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5855
5856<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5857<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5858 specifier determining if the fetch should be for a read (0) or write (1),
5859 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5860 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5861 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5862
5863<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5864<p>This intrinsic does not modify the behavior of the program. In particular,
5865 prefetches cannot trap and do not produce a value. On targets that support
5866 this intrinsic, the prefetch can provide hints to the processor cache for
5867 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5868
5869</div>
5870
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5871<!-- _______________________________________________________________________ -->
5872<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5873 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5874</div>
5875
5876<div class="doc_text">
5877
5878<h5>Syntax:</h5>
5879<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5880 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5881</pre>
5882
5883<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5884<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5885 Counter (PC) in a region of code to simulators and other tools. The method
5886 is target specific, but it is expected that the marker will use exported
5887 symbols to transmit the PC of the marker. The marker makes no guarantees
5888 that it will remain with any specific instruction after optimizations. It is
5889 possible that the presence of a marker will inhibit optimizations. The
5890 intended use is to be inserted after optimizations to allow correlations of
5891 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5892
5893<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5894<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5895
5896<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5897<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5898 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5899
5900</div>
5901
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5902<!-- _______________________________________________________________________ -->
5903<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5904 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5905</div>
5906
5907<div class="doc_text">
5908
5909<h5>Syntax:</h5>
5910<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5911 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5912</pre>
5913
5914<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5915<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5916 counter register (or similar low latency, high accuracy clocks) on those
5917 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5918 should map to RPCC. As the backing counters overflow quickly (on the order
5919 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5920
5921<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5922<p>When directly supported, reading the cycle counter should not modify any
5923 memory. Implementations are allowed to either return a application specific
5924 value or a system wide value. On backends without support, this is lowered
5925 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5926
5927</div>
5928
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5929<!-- ======================================================================= -->
5930<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5931 <a name="int_libc">Standard C Library Intrinsics</a>
5932</div>
5933
5934<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5935
5936<p>LLVM provides intrinsics for a few important standard C library functions.
5937 These intrinsics allow source-language front-ends to pass information about
5938 the alignment of the pointer arguments to the code generator, providing
5939 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5940
5941</div>
5942
5943<!-- _______________________________________________________________________ -->
5944<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5945 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5946</div>
5947
5948<div class="doc_text">
5949
5950<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5951<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]5952 integer bit width and for different address spaces. Not all targets support
5953 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5954
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5955<pre>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]5956 declare void @llvm.memcpy.p0i8.p0i8.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5957 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
5958 declare void @llvm.memcpy.p0i8.p0i8.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5959 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5960</pre>
5961
5962<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5963<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5964 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5965
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5966<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]5967 intrinsics do not return a value, takes extra alignment/isvolatile arguments
5968 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5969
5970<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]5971
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5972<p>The first argument is a pointer to the destination, the second is a pointer
5973 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]5974 number of bytes to copy, the fourth argument is the alignment of the
5975 source and destination locations, and the fifth is a boolean indicating a
5976 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5977
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5978<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]5979 then the caller guarantees that both the source and destination pointers are
5980 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5981
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame^]5982<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
5983 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
5984 The detailed access behavior is not very cleanly specified and it is unwise
5985 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]5986
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5987<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]5988
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5989<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5990 source location to the destination location, which are not allowed to
5991 overlap. It copies "len" bytes of memory over. If the argument is known to
5992 be aligned to some boundary, this can be specified as the fourth argument,
5993 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5994
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5995</div>
5996
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5997<!-- _______________________________________________________________________ -->
5998<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5999 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6000</div>
6001
6002<div class="doc_text">
6003
6004<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6005<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]6006 width and for different address space. Not all targets support all bit
6007 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6008
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6009<pre>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6010 declare void @llvm.memmove.p0i8.p0i8.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
6011 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
6012 declare void @llvm.memmove.p0i8.p0i8.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
6013 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6014</pre>
6015
6016<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6017<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6018 source location to the destination location. It is similar to the
6019 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6020 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6021
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6022<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6023 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6024 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6025
6026<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6027
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6028<p>The first argument is a pointer to the destination, the second is a pointer
6029 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6030 number of bytes to copy, the fourth argument is the alignment of the
6031 source and destination locations, and the fifth is a boolean indicating a
6032 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6033
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6034<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]6035 then the caller guarantees that the source and destination pointers are
6036 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6037
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame^]6038<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6039 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6040 The detailed access behavior is not very cleanly specified and it is unwise
6041 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6042
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6043<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6044
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6045<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6046 source location to the destination location, which may overlap. It copies
6047 "len" bytes of memory over. If the argument is known to be aligned to some
6048 boundary, this can be specified as the fourth argument, otherwise it should
6049 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6050
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6051</div>
6052
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6053<!-- _______________________________________________________________________ -->
6054<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6055 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6056</div>
6057
6058<div class="doc_text">
6059
6060<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6061<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Mon P Wang508127b2010-04-07 06:35:53 +0000[diff] [blame]6062 width and for different address spaces. Not all targets support all bit
6063 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6064
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6065<pre>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6066 declare void @llvm.memset.p0i8.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6067 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6068 declare void @llvm.memset.p0i8.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6069 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6070</pre>
6071
6072<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6073<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6074 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6075
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6076<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6077 intrinsic does not return a value, takes extra alignment/volatile arguments,
6078 and the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6079
6080<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6081<p>The first argument is a pointer to the destination to fill, the second is the
6082 byte value to fill it with, the third argument is an integer argument
6083 specifying the number of bytes to fill, and the fourth argument is the known
6084 alignment of destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6085
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6086<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]6087 then the caller guarantees that the destination pointer is aligned to that
6088 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6089
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame^]6090<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6091 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6092 The detailed access behavior is not very cleanly specified and it is unwise
6093 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6094
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6095<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6096<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6097 at the destination location. If the argument is known to be aligned to some
6098 boundary, this can be specified as the fourth argument, otherwise it should
6099 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6100
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6101</div>
6102
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6103<!-- _______________________________________________________________________ -->
6104<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6105 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6106</div>
6107
6108<div class="doc_text">
6109
6110<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6111<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6112 floating point or vector of floating point type. Not all targets support all
6113 types however.</p>
6114
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6115<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6116 declare float @llvm.sqrt.f32(float %Val)
6117 declare double @llvm.sqrt.f64(double %Val)
6118 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6119 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6120 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6121</pre>
6122
6123<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6124<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6125 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6126 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6127 behavior for negative numbers other than -0.0 (which allows for better
6128 optimization, because there is no need to worry about errno being
6129 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]6130
6131<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6132<p>The argument and return value are floating point numbers of the same
6133 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6134
6135<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6136<p>This function returns the sqrt of the specified operand if it is a
6137 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6138
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6139</div>
6140
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6141<!-- _______________________________________________________________________ -->
6142<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6143 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6144</div>
6145
6146<div class="doc_text">
6147
6148<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6149<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6150 floating point or vector of floating point type. Not all targets support all
6151 types however.</p>
6152
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6153<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6154 declare float @llvm.powi.f32(float %Val, i32 %power)
6155 declare double @llvm.powi.f64(double %Val, i32 %power)
6156 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6157 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6158 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6159</pre>
6160
6161<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6162<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6163 specified (positive or negative) power. The order of evaluation of
6164 multiplications is not defined. When a vector of floating point type is
6165 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6166
6167<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6168<p>The second argument is an integer power, and the first is a value to raise to
6169 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6170
6171<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6172<p>This function returns the first value raised to the second power with an
6173 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6174
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6175</div>
6176
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6177<!-- _______________________________________________________________________ -->
6178<div class="doc_subsubsection">
6179 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
6180</div>
6181
6182<div class="doc_text">
6183
6184<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6185<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6186 floating point or vector of floating point type. Not all targets support all
6187 types however.</p>
6188
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6189<pre>
6190 declare float @llvm.sin.f32(float %Val)
6191 declare double @llvm.sin.f64(double %Val)
6192 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6193 declare fp128 @llvm.sin.f128(fp128 %Val)
6194 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6195</pre>
6196
6197<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6198<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6199
6200<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6201<p>The argument and return value are floating point numbers of the same
6202 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6203
6204<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6205<p>This function returns the sine of the specified operand, returning the same
6206 values as the libm <tt>sin</tt> functions would, and handles error conditions
6207 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6208
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6209</div>
6210
6211<!-- _______________________________________________________________________ -->
6212<div class="doc_subsubsection">
6213 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
6214</div>
6215
6216<div class="doc_text">
6217
6218<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6219<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6220 floating point or vector of floating point type. Not all targets support all
6221 types however.</p>
6222
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6223<pre>
6224 declare float @llvm.cos.f32(float %Val)
6225 declare double @llvm.cos.f64(double %Val)
6226 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6227 declare fp128 @llvm.cos.f128(fp128 %Val)
6228 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6229</pre>
6230
6231<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6232<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6233
6234<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6235<p>The argument and return value are floating point numbers of the same
6236 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6237
6238<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6239<p>This function returns the cosine of the specified operand, returning the same
6240 values as the libm <tt>cos</tt> functions would, and handles error conditions
6241 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6242
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6243</div>
6244
6245<!-- _______________________________________________________________________ -->
6246<div class="doc_subsubsection">
6247 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
6248</div>
6249
6250<div class="doc_text">
6251
6252<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6253<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6254 floating point or vector of floating point type. Not all targets support all
6255 types however.</p>
6256
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6257<pre>
6258 declare float @llvm.pow.f32(float %Val, float %Power)
6259 declare double @llvm.pow.f64(double %Val, double %Power)
6260 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6261 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6262 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6263</pre>
6264
6265<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6266<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6267 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6268
6269<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6270<p>The second argument is a floating point power, and the first is a value to
6271 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6272
6273<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6274<p>This function returns the first value raised to the second power, returning
6275 the same values as the libm <tt>pow</tt> functions would, and handles error
6276 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6277
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6278</div>
6279
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6280<!-- ======================================================================= -->
6281<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6282 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6283</div>
6284
6285<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6286
6287<p>LLVM provides intrinsics for a few important bit manipulation operations.
6288 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6289
6290</div>
6291
6292<!-- _______________________________________________________________________ -->
6293<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6294 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6295</div>
6296
6297<div class="doc_text">
6298
6299<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6300<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6301 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6302
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6303<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6304 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6305 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6306 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6307</pre>
6308
6309<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6310<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6311 values with an even number of bytes (positive multiple of 16 bits). These
6312 are useful for performing operations on data that is not in the target's
6313 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6314
6315<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6316<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6317 and low byte of the input i16 swapped. Similarly,
6318 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6319 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6320 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6321 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6322 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6323 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6324
6325</div>
6326
6327<!-- _______________________________________________________________________ -->
6328<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6329 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6330</div>
6331
6332<div class="doc_text">
6333
6334<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6335<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6336 width. Not all targets support all bit widths however.</p>
6337
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6338<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6339 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6340 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6341 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6342 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6343 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6344</pre>
6345
6346<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6347<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6348 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6349
6350<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6351<p>The only argument is the value to be counted. The argument may be of any
6352 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6353
6354<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6355<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6356
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6357</div>
6358
6359<!-- _______________________________________________________________________ -->
6360<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6361 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6362</div>
6363
6364<div class="doc_text">
6365
6366<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6367<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6368 integer bit width. Not all targets support all bit widths however.</p>
6369
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6370<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6371 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6372 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6373 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6374 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6375 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6376</pre>
6377
6378<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6379<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6380 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6381
6382<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6383<p>The only argument is the value to be counted. The argument may be of any
6384 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6385
6386<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6387<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6388 zeros in a variable. If the src == 0 then the result is the size in bits of
6389 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6390
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6391</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6392
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6393<!-- _______________________________________________________________________ -->
6394<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6395 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6396</div>
6397
6398<div class="doc_text">
6399
6400<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6401<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6402 integer bit width. Not all targets support all bit widths however.</p>
6403
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6404<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6405 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6406 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6407 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6408 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6409 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6410</pre>
6411
6412<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6413<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6414 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6415
6416<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6417<p>The only argument is the value to be counted. The argument may be of any
6418 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6419
6420<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6421<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6422 zeros in a variable. If the src == 0 then the result is the size in bits of
6423 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6424
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6425</div>
6426
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6427<!-- ======================================================================= -->
6428<div class="doc_subsection">
6429 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6430</div>
6431
6432<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6433
6434<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6435
6436</div>
6437
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6438<!-- _______________________________________________________________________ -->
6439<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6440 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6441</div>
6442
6443<div class="doc_text">
6444
6445<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6446<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]6447 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6448
6449<pre>
6450 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6451 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6452 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6453</pre>
6454
6455<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6456<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6457 a signed addition of the two arguments, and indicate whether an overflow
6458 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6459
6460<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6461<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]6462 be of integer types of any bit width, but they must have the same bit
6463 width. The second element of the result structure must be of
6464 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6465 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6466
6467<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6468<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6469 a signed addition of the two variables. They return a structure &mdash; the
6470 first element of which is the signed summation, and the second element of
6471 which is a bit specifying if the signed summation resulted in an
6472 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6473
6474<h5>Examples:</h5>
6475<pre>
6476 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6477 %sum = extractvalue {i32, i1} %res, 0
6478 %obit = extractvalue {i32, i1} %res, 1
6479 br i1 %obit, label %overflow, label %normal
6480</pre>
6481
6482</div>
6483
6484<!-- _______________________________________________________________________ -->
6485<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6486 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6487</div>
6488
6489<div class="doc_text">
6490
6491<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6492<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]6493 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6494
6495<pre>
6496 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6497 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6498 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6499</pre>
6500
6501<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6502<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6503 an unsigned addition of the two arguments, and indicate whether a carry
6504 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6505
6506<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6507<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]6508 be of integer types of any bit width, but they must have the same bit
6509 width. The second element of the result structure must be of
6510 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6511 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6512
6513<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6514<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6515 an unsigned addition of the two arguments. They return a structure &mdash;
6516 the first element of which is the sum, and the second element of which is a
6517 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6518
6519<h5>Examples:</h5>
6520<pre>
6521 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6522 %sum = extractvalue {i32, i1} %res, 0
6523 %obit = extractvalue {i32, i1} %res, 1
6524 br i1 %obit, label %carry, label %normal
6525</pre>
6526
6527</div>
6528
6529<!-- _______________________________________________________________________ -->
6530<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6531 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6532</div>
6533
6534<div class="doc_text">
6535
6536<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6537<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]6538 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6539
6540<pre>
6541 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6542 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6543 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6544</pre>
6545
6546<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6547<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6548 a signed subtraction of the two arguments, and indicate whether an overflow
6549 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6550
6551<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6552<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]6553 be of integer types of any bit width, but they must have the same bit
6554 width. The second element of the result structure must be of
6555 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6556 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6557
6558<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6559<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6560 a signed subtraction of the two arguments. They return a structure &mdash;
6561 the first element of which is the subtraction, and the second element of
6562 which is a bit specifying if the signed subtraction resulted in an
6563 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6564
6565<h5>Examples:</h5>
6566<pre>
6567 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6568 %sum = extractvalue {i32, i1} %res, 0
6569 %obit = extractvalue {i32, i1} %res, 1
6570 br i1 %obit, label %overflow, label %normal
6571</pre>
6572
6573</div>
6574
6575<!-- _______________________________________________________________________ -->
6576<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6577 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6578</div>
6579
6580<div class="doc_text">
6581
6582<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6583<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]6584 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6585
6586<pre>
6587 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6588 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6589 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6590</pre>
6591
6592<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6593<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6594 an unsigned subtraction of the two arguments, and indicate whether an
6595 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6596
6597<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6598<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]6599 be of integer types of any bit width, but they must have the same bit
6600 width. The second element of the result structure must be of
6601 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6602 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6603
6604<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6605<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6606 an unsigned subtraction of the two arguments. They return a structure &mdash;
6607 the first element of which is the subtraction, and the second element of
6608 which is a bit specifying if the unsigned subtraction resulted in an
6609 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6610
6611<h5>Examples:</h5>
6612<pre>
6613 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6614 %sum = extractvalue {i32, i1} %res, 0
6615 %obit = extractvalue {i32, i1} %res, 1
6616 br i1 %obit, label %overflow, label %normal
6617</pre>
6618
6619</div>
6620
6621<!-- _______________________________________________________________________ -->
6622<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6623 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6624</div>
6625
6626<div class="doc_text">
6627
6628<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6629<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]6630 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6631
6632<pre>
6633 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6634 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6635 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6636</pre>
6637
6638<h5>Overview:</h5>
6639
6640<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6641 a signed multiplication of the two arguments, and indicate whether an
6642 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6643
6644<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6645<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]6646 be of integer types of any bit width, but they must have the same bit
6647 width. The second element of the result structure must be of
6648 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6649 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6650
6651<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6652<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6653 a signed multiplication of the two arguments. They return a structure &mdash;
6654 the first element of which is the multiplication, and the second element of
6655 which is a bit specifying if the signed multiplication resulted in an
6656 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6657
6658<h5>Examples:</h5>
6659<pre>
6660 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6661 %sum = extractvalue {i32, i1} %res, 0
6662 %obit = extractvalue {i32, i1} %res, 1
6663 br i1 %obit, label %overflow, label %normal
6664</pre>
6665
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6666</div>
6667
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6668<!-- _______________________________________________________________________ -->
6669<div class="doc_subsubsection">
6670 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6671</div>
6672
6673<div class="doc_text">
6674
6675<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6676<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]6677 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6678
6679<pre>
6680 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6681 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6682 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6683</pre>
6684
6685<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6686<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6687 a unsigned multiplication of the two arguments, and indicate whether an
6688 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6689
6690<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6691<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]6692 be of integer types of any bit width, but they must have the same bit
6693 width. The second element of the result structure must be of
6694 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6695 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6696
6697<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6698<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6699 an unsigned multiplication of the two arguments. They return a structure
6700 &mdash; the first element of which is the multiplication, and the second
6701 element of which is a bit specifying if the unsigned multiplication resulted
6702 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6703
6704<h5>Examples:</h5>
6705<pre>
6706 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6707 %sum = extractvalue {i32, i1} %res, 0
6708 %obit = extractvalue {i32, i1} %res, 1
6709 br i1 %obit, label %overflow, label %normal
6710</pre>
6711
6712</div>
6713
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6714<!-- ======================================================================= -->
6715<div class="doc_subsection">
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6716 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
6717</div>
6718
6719<div class="doc_text">
6720
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]6721<p>Half precision floating point is a storage-only format. This means that it is
6722 a dense encoding (in memory) but does not support computation in the
6723 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]6724
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]6725<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]6726 value as an i16, then convert it to float with <a
6727 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
6728 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]6729 double etc). To store the value back to memory, it is first converted to
6730 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]6731 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
6732 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6733</div>
6734
6735<!-- _______________________________________________________________________ -->
6736<div class="doc_subsubsection">
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]6737 <a name="int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6738</div>
6739
6740<div class="doc_text">
6741
6742<h5>Syntax:</h5>
6743<pre>
6744 declare i16 @llvm.convert.to.fp16(f32 %a)
6745</pre>
6746
6747<h5>Overview:</h5>
6748<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6749 a conversion from single precision floating point format to half precision
6750 floating point format.</p>
6751
6752<h5>Arguments:</h5>
6753<p>The intrinsic function contains single argument - the value to be
6754 converted.</p>
6755
6756<h5>Semantics:</h5>
6757<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6758 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]6759 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]6760 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6761
6762<h5>Examples:</h5>
6763<pre>
6764 %res = call i16 @llvm.convert.to.fp16(f32 %a)
6765 store i16 %res, i16* @x, align 2
6766</pre>
6767
6768</div>
6769
6770<!-- _______________________________________________________________________ -->
6771<div class="doc_subsubsection">
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]6772 <a name="int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6773</div>
6774
6775<div class="doc_text">
6776
6777<h5>Syntax:</h5>
6778<pre>
6779 declare f32 @llvm.convert.from.fp16(i16 %a)
6780</pre>
6781
6782<h5>Overview:</h5>
6783<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
6784 a conversion from half precision floating point format to single precision
6785 floating point format.</p>
6786
6787<h5>Arguments:</h5>
6788<p>The intrinsic function contains single argument - the value to be
6789 converted.</p>
6790
6791<h5>Semantics:</h5>
6792<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]6793 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]6794 precision floating point format. The input half-float value is represented by
6795 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6796
6797<h5>Examples:</h5>
6798<pre>
6799 %a = load i16* @x, align 2
6800 %res = call f32 @llvm.convert.from.fp16(i16 %a)
6801</pre>
6802
6803</div>
6804
6805<!-- ======================================================================= -->
6806<div class="doc_subsection">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6807 <a name="int_debugger">Debugger Intrinsics</a>
6808</div>
6809
6810<div class="doc_text">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6811
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6812<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6813 prefix), are described in
6814 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6815 Level Debugging</a> document.</p>
6816
6817</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6818
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6819<!-- ======================================================================= -->
6820<div class="doc_subsection">
6821 <a name="int_eh">Exception Handling Intrinsics</a>
6822</div>
6823
6824<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6825
6826<p>The LLVM exception handling intrinsics (which all start with
6827 <tt>llvm.eh.</tt> prefix), are described in
6828 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6829 Handling</a> document.</p>
6830
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6831</div>
6832
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6833<!-- ======================================================================= -->
6834<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6835 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6836</div>
6837
6838<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6839
6840<p>This intrinsic makes it possible to excise one parameter, marked with
6841 the <tt>nest</tt> attribute, from a function. The result is a callable
6842 function pointer lacking the nest parameter - the caller does not need to
6843 provide a value for it. Instead, the value to use is stored in advance in a
6844 "trampoline", a block of memory usually allocated on the stack, which also
6845 contains code to splice the nest value into the argument list. This is used
6846 to implement the GCC nested function address extension.</p>
6847
6848<p>For example, if the function is
6849 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6850 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6851 follows:</p>
6852
6853<div class="doc_code">
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6854<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6855 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6856 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6857 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6858 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6859</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6860</div>
6861
6862<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6863 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6864
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6865</div>
6866
6867<!-- _______________________________________________________________________ -->
6868<div class="doc_subsubsection">
6869 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6870</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6871
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6872<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6873
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6874<h5>Syntax:</h5>
6875<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6876 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]6877</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6878
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6879<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6880<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6881 function pointer suitable for executing it.</p>
6882
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6883<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6884<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6885 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6886 sufficiently aligned block of memory; this memory is written to by the
6887 intrinsic. Note that the size and the alignment are target-specific - LLVM
6888 currently provides no portable way of determining them, so a front-end that
6889 generates this intrinsic needs to have some target-specific knowledge.
6890 The <tt>func</tt> argument must hold a function bitcast to
6891 an <tt>i8*</tt>.</p>
6892
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6893<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6894<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6895 dependent code, turning it into a function. A pointer to this function is
6896 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6897 function pointer type</a> before being called. The new function's signature
6898 is the same as that of <tt>func</tt> with any arguments marked with
6899 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6900 is allowed, and it must be of pointer type. Calling the new function is
6901 equivalent to calling <tt>func</tt> with the same argument list, but
6902 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6903 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6904 by <tt>tramp</tt> is modified, then the effect of any later call to the
6905 returned function pointer is undefined.</p>
6906
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6907</div>
6908
6909<!-- ======================================================================= -->
6910<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6911 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6912</div>
6913
6914<div class="doc_text">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6915
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6916<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6917 hardware constructs for atomic operations and memory synchronization. This
6918 provides an interface to the hardware, not an interface to the programmer. It
6919 is aimed at a low enough level to allow any programming models or APIs
6920 (Application Programming Interfaces) which need atomic behaviors to map
6921 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6922 hardware provides a "universal IR" for source languages, it also provides a
6923 starting point for developing a "universal" atomic operation and
6924 synchronization IR.</p>
6925
6926<p>These do <em>not</em> form an API such as high-level threading libraries,
6927 software transaction memory systems, atomic primitives, and intrinsic
6928 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6929 application libraries. The hardware interface provided by LLVM should allow
6930 a clean implementation of all of these APIs and parallel programming models.
6931 No one model or paradigm should be selected above others unless the hardware
6932 itself ubiquitously does so.</p>
6933
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6934</div>
6935
6936<!-- _______________________________________________________________________ -->
6937<div class="doc_subsubsection">
6938 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6939</div>
6940<div class="doc_text">
6941<h5>Syntax:</h5>
6942<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6943 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]6944</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6945
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6946<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6947<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6948 specific pairs of memory access types.</p>
6949
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6950<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6951<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6952 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6953 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6954 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6955
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6956<ul>
6957 <li><tt>ll</tt>: load-load barrier</li>
6958 <li><tt>ls</tt>: load-store barrier</li>
6959 <li><tt>sl</tt>: store-load barrier</li>
6960 <li><tt>ss</tt>: store-store barrier</li>
6961 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6962</ul>
6963
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6964<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6965<p>This intrinsic causes the system to enforce some ordering constraints upon
6966 the loads and stores of the program. This barrier does not
6967 indicate <em>when</em> any events will occur, it only enforces
6968 an <em>order</em> in which they occur. For any of the specified pairs of load
6969 and store operations (f.ex. load-load, or store-load), all of the first
6970 operations preceding the barrier will complete before any of the second
6971 operations succeeding the barrier begin. Specifically the semantics for each
6972 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6973
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6974<ul>
6975 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6976 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6977 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6978 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6979 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6980 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6981 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6982 load after the barrier begins.</li>
6983</ul>
6984
6985<p>These semantics are applied with a logical "and" behavior when more than one
6986 is enabled in a single memory barrier intrinsic.</p>
6987
6988<p>Backends may implement stronger barriers than those requested when they do
6989 not support as fine grained a barrier as requested. Some architectures do
6990 not need all types of barriers and on such architectures, these become
6991 noops.</p>
6992
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6993<h5>Example:</h5>
6994<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6995%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6996%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6997 store i32 4, %ptr
6998
6999%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
7000 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
7001 <i>; guarantee the above finishes</i>
7002 store i32 8, %ptr <i>; before this begins</i>
7003</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7004
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7005</div>
7006
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7007<!-- _______________________________________________________________________ -->
7008<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7009 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7010</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7011
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7012<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7013
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7014<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7015<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7016 any integer bit width and for different address spaces. Not all targets
7017 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7018
7019<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7020 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
7021 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
7022 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
7023 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]7024</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7025
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7026<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7027<p>This loads a value in memory and compares it to a given value. If they are
7028 equal, it stores a new value into the memory.</p>
7029
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7030<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7031<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7032 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7033 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7034 this integer type. While any bit width integer may be used, targets may only
7035 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7036
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7037<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7038<p>This entire intrinsic must be executed atomically. It first loads the value
7039 in memory pointed to by <tt>ptr</tt> and compares it with the
7040 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7041 memory. The loaded value is yielded in all cases. This provides the
7042 equivalent of an atomic compare-and-swap operation within the SSA
7043 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7044
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7045<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7046<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7047%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7048%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7049 store i32 4, %ptr
7050
7051%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7052%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7053 <i>; yields {i32}:result1 = 4</i>
7054%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7055%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7056
7057%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7058%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7059 <i>; yields {i32}:result2 = 8</i>
7060%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7061
7062%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7063</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7064
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7065</div>
7066
7067<!-- _______________________________________________________________________ -->
7068<div class="doc_subsubsection">
7069 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
7070</div>
7071<div class="doc_text">
7072<h5>Syntax:</h5>
7073
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7074<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7075 integer bit width. Not all targets support all bit widths however.</p>
7076
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7077<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7078 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
7079 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
7080 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
7081 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]7082</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7083
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7084<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7085<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7086 the value from memory. It then stores the value in <tt>val</tt> in the memory
7087 at <tt>ptr</tt>.</p>
7088
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7089<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7090<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7091 the <tt>val</tt> argument and the result must be integers of the same bit
7092 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7093 integer type. The targets may only lower integer representations they
7094 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7095
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7096<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7097<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7098 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7099 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7100
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7101<h5>Examples:</h5>
7102<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7103%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7104%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7105 store i32 4, %ptr
7106
7107%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7108%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7109 <i>; yields {i32}:result1 = 4</i>
7110%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7111%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7112
7113%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7114%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7115 <i>; yields {i32}:result2 = 8</i>
7116
7117%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7118%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7119</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7120
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7121</div>
7122
7123<!-- _______________________________________________________________________ -->
7124<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7125 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7126
7127</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7128
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7129<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7130
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7131<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7132<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7133 any integer bit width. Not all targets support all bit widths however.</p>
7134
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7135<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7136 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7137 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7138 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7139 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]7140</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7141
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7142<h5>Overview:</h5>
7143<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7144 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7145
7146<h5>Arguments:</h5>
7147<p>The intrinsic takes two arguments, the first a pointer to an integer value
7148 and the second an integer value. The result is also an integer value. These
7149 integer types can have any bit width, but they must all have the same bit
7150 width. The targets may only lower integer representations they support.</p>
7151
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7152<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7153<p>This intrinsic does a series of operations atomically. It first loads the
7154 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7155 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]7156
7157<h5>Examples:</h5>
7158<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7159%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7160%ptr = bitcast i8* %mallocP to i32*
7161 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7162%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7163 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7164%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7165 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7166%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7167 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7168%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7169</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7170
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7171</div>
7172
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7173<!-- _______________________________________________________________________ -->
7174<div class="doc_subsubsection">
7175 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
7176
7177</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7178
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7179<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7180
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7181<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7182<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7183 any integer bit width and for different address spaces. Not all targets
7184 support all bit widths however.</p>
7185
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7186<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7187 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7188 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7189 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7190 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]7191</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7192
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7193<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7194<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7195 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7196
7197<h5>Arguments:</h5>
7198<p>The intrinsic takes two arguments, the first a pointer to an integer value
7199 and the second an integer value. The result is also an integer value. These
7200 integer types can have any bit width, but they must all have the same bit
7201 width. The targets may only lower integer representations they support.</p>
7202
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7203<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7204<p>This intrinsic does a series of operations atomically. It first loads the
7205 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7206 result to <tt>ptr</tt>. It yields the original value stored
7207 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7208
7209<h5>Examples:</h5>
7210<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7211%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7212%ptr = bitcast i8* %mallocP to i32*
7213 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7214%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7215 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7216%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7217 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7218%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7219 <i>; yields {i32}:result3 = 2</i>
7220%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7221</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7222
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7223</div>
7224
7225<!-- _______________________________________________________________________ -->
7226<div class="doc_subsubsection">
7227 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
7228 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
7229 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
7230 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7231</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7232
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7233<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7234
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7235<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7236<p>These are overloaded intrinsics. You can
7237 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7238 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7239 bit width and for different address spaces. Not all targets support all bit
7240 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7241
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7242<pre>
7243 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7244 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7245 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7246 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]7247</pre>
7248
7249<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7250 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7251 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7252 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7253 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]7254</pre>
7255
7256<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7257 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7258 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7259 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7260 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]7261</pre>
7262
7263<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7264 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7265 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7266 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7267 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]7268</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7269
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7270<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7271<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7272 the value stored in memory at <tt>ptr</tt>. It yields the original value
7273 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7274
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7275<h5>Arguments:</h5>
7276<p>These intrinsics take two arguments, the first a pointer to an integer value
7277 and the second an integer value. The result is also an integer value. These
7278 integer types can have any bit width, but they must all have the same bit
7279 width. The targets may only lower integer representations they support.</p>
7280
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7281<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7282<p>These intrinsics does a series of operations atomically. They first load the
7283 value stored at <tt>ptr</tt>. They then do the bitwise
7284 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7285 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7286
7287<h5>Examples:</h5>
7288<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7289%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7290%ptr = bitcast i8* %mallocP to i32*
7291 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7292%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7293 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7294%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7295 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7296%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7297 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7298%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7299 <i>; yields {i32}:result3 = FF</i>
7300%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7301</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7302
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7303</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7304
7305<!-- _______________________________________________________________________ -->
7306<div class="doc_subsubsection">
7307 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
7308 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
7309 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
7310 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7311</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7312
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7313<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7314
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7315<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7316<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7317 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7318 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7319 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7320
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7321<pre>
7322 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7323 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7324 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7325 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]7326</pre>
7327
7328<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7329 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7330 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7331 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7332 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]7333</pre>
7334
7335<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7336 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7337 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7338 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7339 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]7340</pre>
7341
7342<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7343 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7344 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7345 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7346 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]7347</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7348
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7349<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7350<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7351 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7352 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7353
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7354<h5>Arguments:</h5>
7355<p>These intrinsics take two arguments, the first a pointer to an integer value
7356 and the second an integer value. The result is also an integer value. These
7357 integer types can have any bit width, but they must all have the same bit
7358 width. The targets may only lower integer representations they support.</p>
7359
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7360<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7361<p>These intrinsics does a series of operations atomically. They first load the
7362 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7363 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7364 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7365
7366<h5>Examples:</h5>
7367<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7368%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7369%ptr = bitcast i8* %mallocP to i32*
7370 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7371%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7372 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7373%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7374 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7375%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7376 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7377%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7378 <i>; yields {i32}:result3 = 8</i>
7379%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7380</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7381
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7382</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7383
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7384
7385<!-- ======================================================================= -->
7386<div class="doc_subsection">
7387 <a name="int_memorymarkers">Memory Use Markers</a>
7388</div>
7389
7390<div class="doc_text">
7391
7392<p>This class of intrinsics exists to information about the lifetime of memory
7393 objects and ranges where variables are immutable.</p>
7394
7395</div>
7396
7397<!-- _______________________________________________________________________ -->
7398<div class="doc_subsubsection">
7399 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7400</div>
7401
7402<div class="doc_text">
7403
7404<h5>Syntax:</h5>
7405<pre>
7406 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7407</pre>
7408
7409<h5>Overview:</h5>
7410<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7411 object's lifetime.</p>
7412
7413<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7414<p>The first argument is a constant integer representing the size of the
7415 object, or -1 if it is variable sized. The second argument is a pointer to
7416 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7417
7418<h5>Semantics:</h5>
7419<p>This intrinsic indicates that before this point in the code, the value of the
7420 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]7421 never be used and has an undefined value. A load from the pointer that
7422 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7423 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7424
7425</div>
7426
7427<!-- _______________________________________________________________________ -->
7428<div class="doc_subsubsection">
7429 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7430</div>
7431
7432<div class="doc_text">
7433
7434<h5>Syntax:</h5>
7435<pre>
7436 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7437</pre>
7438
7439<h5>Overview:</h5>
7440<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7441 object's lifetime.</p>
7442
7443<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7444<p>The first argument is a constant integer representing the size of the
7445 object, or -1 if it is variable sized. The second argument is a pointer to
7446 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7447
7448<h5>Semantics:</h5>
7449<p>This intrinsic indicates that after this point in the code, the value of the
7450 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7451 never be used and has an undefined value. Any stores into the memory object
7452 following this intrinsic may be removed as dead.
7453
7454</div>
7455
7456<!-- _______________________________________________________________________ -->
7457<div class="doc_subsubsection">
7458 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7459</div>
7460
7461<div class="doc_text">
7462
7463<h5>Syntax:</h5>
7464<pre>
7465 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7466</pre>
7467
7468<h5>Overview:</h5>
7469<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7470 a memory object will not change.</p>
7471
7472<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7473<p>The first argument is a constant integer representing the size of the
7474 object, or -1 if it is variable sized. The second argument is a pointer to
7475 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7476
7477<h5>Semantics:</h5>
7478<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7479 the return value, the referenced memory location is constant and
7480 unchanging.</p>
7481
7482</div>
7483
7484<!-- _______________________________________________________________________ -->
7485<div class="doc_subsubsection">
7486 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7487</div>
7488
7489<div class="doc_text">
7490
7491<h5>Syntax:</h5>
7492<pre>
7493 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7494</pre>
7495
7496<h5>Overview:</h5>
7497<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7498 a memory object are mutable.</p>
7499
7500<h5>Arguments:</h5>
7501<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7502 The second argument is a constant integer representing the size of the
7503 object, or -1 if it is variable sized and the third argument is a pointer
7504 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7505
7506<h5>Semantics:</h5>
7507<p>This intrinsic indicates that the memory is mutable again.</p>
7508
7509</div>
7510
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7511<!-- ======================================================================= -->
7512<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7513 <a name="int_general">General Intrinsics</a>
7514</div>
7515
7516<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7517
7518<p>This class of intrinsics is designed to be generic and has no specific
7519 purpose.</p>
7520
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7521</div>
7522
7523<!-- _______________________________________________________________________ -->
7524<div class="doc_subsubsection">
7525 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7526</div>
7527
7528<div class="doc_text">
7529
7530<h5>Syntax:</h5>
7531<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]7532 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]7533</pre>
7534
7535<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7536<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7537
7538<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7539<p>The first argument is a pointer to a value, the second is a pointer to a
7540 global string, the third is a pointer to a global string which is the source
7541 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7542
7543<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7544<p>This intrinsic allows annotation of local variables with arbitrary strings.
7545 This can be useful for special purpose optimizations that want to look for
7546 these annotations. These have no other defined use, they are ignored by code
7547 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7548
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7549</div>
7550
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7551<!-- _______________________________________________________________________ -->
7552<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7553 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7554</div>
7555
7556<div class="doc_text">
7557
7558<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7559<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7560 any integer bit width.</p>
7561
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7562<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]7563 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7564 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7565 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7566 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7567 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]7568</pre>
7569
7570<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7571<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7572
7573<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7574<p>The first argument is an integer value (result of some expression), the
7575 second is a pointer to a global string, the third is a pointer to a global
7576 string which is the source file name, and the last argument is the line
7577 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7578
7579<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7580<p>This intrinsic allows annotations to be put on arbitrary expressions with
7581 arbitrary strings. This can be useful for special purpose optimizations that
7582 want to look for these annotations. These have no other defined use, they
7583 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7584
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7585</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7586
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7587<!-- _______________________________________________________________________ -->
7588<div class="doc_subsubsection">
7589 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7590</div>
7591
7592<div class="doc_text">
7593
7594<h5>Syntax:</h5>
7595<pre>
7596 declare void @llvm.trap()
7597</pre>
7598
7599<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7600<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7601
7602<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7603<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7604
7605<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7606<p>This intrinsics is lowered to the target dependent trap instruction. If the
7607 target does not have a trap instruction, this intrinsic will be lowered to
7608 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7609
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7610</div>
7611
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7612<!-- _______________________________________________________________________ -->
7613<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7614 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7615</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7616
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7617<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7618
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7619<h5>Syntax:</h5>
7620<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7621 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7622</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7623
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7624<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7625<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7626 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7627 ensure that it is placed on the stack before local variables.</p>
7628
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7629<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7630<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7631 arguments. The first argument is the value loaded from the stack
7632 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7633 that has enough space to hold the value of the guard.</p>
7634
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7635<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7636<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7637 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7638 stack. This is to ensure that if a local variable on the stack is
7639 overwritten, it will destroy the value of the guard. When the function exits,
7640 the guard on the stack is checked against the original guard. If they're
7641 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7642 function.</p>
7643
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7644</div>
7645
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7646<!-- _______________________________________________________________________ -->
7647<div class="doc_subsubsection">
7648 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7649</div>
7650
7651<div class="doc_text">
7652
7653<h5>Syntax:</h5>
7654<pre>
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7655 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7656 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7657</pre>
7658
7659<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7660<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopher3070e162010-01-08 21:42:39 +0000[diff] [blame]7661 to the optimizers to discover at compile time either a) when an
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7662 operation like memcpy will either overflow a buffer that corresponds to
7663 an object, or b) to determine that a runtime check for overflow isn't
7664 necessary. An object in this context means an allocation of a
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7665 specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7666
7667<h5>Arguments:</h5>
7668<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7669 argument is a pointer to or into the <tt>object</tt>. The second argument
7670 is a boolean 0 or 1. This argument determines whether you want the
7671 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7672 1, variables are not allowed.</p>
7673
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7674<h5>Semantics:</h5>
7675<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7676 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7677 (depending on the <tt>type</tt> argument if the size cannot be determined
7678 at compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7679
7680</div>
7681
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7682<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7683<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7684<address>
7685 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7686 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7687 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7688 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]7689
7690 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]7691 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7692 Last modified: $Date$
7693</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]7694
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]7695</body>
7696</html>