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gerrit-public.fairphone.software / toolchain / llvm-project / fe994279ad2f0e11d325b74b1fb38401e59323fc / . / llvm / docs / LangRef.html
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Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3<html>
4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
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>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]50 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]51 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]52 </ol>
53 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]54 <li><a href="#typesystem">Type System</a>
55 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]56 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]57 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]58 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]59 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]60 <li><a href="#t_floating">Floating Point Types</a></li>
61 <li><a href="#t_void">Void Type</a></li>
62 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]63 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]64 </ol>
65 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]66 <li><a href="#t_derived">Derived Types</a>
67 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]68 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]69 <li><a href="#t_function">Function Type</a></li>
70 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]72 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]73 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]74 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]75 </ol>
76 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]77 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]78 </ol>
79 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]80 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]81 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]82 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]83 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]84 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
85 <li><a href="#undefvalues">Undefined Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]86 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]87 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]88 <li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]89 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]90 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]91 <li><a href="#othervalues">Other Values</a>
92 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]94 </ol>
95 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]96 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
97 <ol>
98 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]99 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
100 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]101 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
102 Global Variable</a></li>
103 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
104 Global Variable</a></li>
105 </ol>
106 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]107 <li><a href="#instref">Instruction Reference</a>
108 <ol>
109 <li><a href="#terminators">Terminator Instructions</a>
110 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]111 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
112 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]113 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]114 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]115 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]116 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]117 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]118 </ol>
119 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]120 <li><a href="#binaryops">Binary Operations</a>
121 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]123 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]125 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]127 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]128 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
129 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
130 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]131 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
132 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
133 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]134 </ol>
135 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]136 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
137 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]138 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
139 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
140 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]141 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]142 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]143 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]144 </ol>
145 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]146 <li><a href="#vectorops">Vector Operations</a>
147 <ol>
148 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
149 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
150 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]151 </ol>
152 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]153 <li><a href="#aggregateops">Aggregate Operations</a>
154 <ol>
155 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
156 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
157 </ol>
158 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]159 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]160 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]161 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]162 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
163 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
164 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]165 </ol>
166 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]167 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]168 <ol>
169 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
170 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]174 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
175 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
176 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]178 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
179 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]180 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]181 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]182 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]183 <li><a href="#otherops">Other Operations</a>
184 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]185 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
186 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]187 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]188 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]189 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]190 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]191 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]192 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]193 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]194 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]195 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]196 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
198 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]199 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]202 </ol>
203 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]204 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
205 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]206 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]211 <li><a href="#int_codegen">Code Generator Intrinsics</a>
212 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
216 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
217 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
218 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
219 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]220 </ol>
221 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]222 <li><a href="#int_libc">Standard C Library Intrinsics</a>
223 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]224 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]229 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]232 </ol>
233 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]234 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]235 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]236 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]237 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]240 </ol>
241 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]242 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
243 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]244 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
248 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]249 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]250 </ol>
251 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]252 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]253 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]254 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]255 <ol>
256 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]259 <li><a href="#int_atomics">Atomic intrinsics</a>
260 <ol>
261 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
262 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
263 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
264 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
265 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
266 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
267 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
268 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
269 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
270 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
271 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
272 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
273 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
274 </ol>
275 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]276 <li><a href="#int_memorymarkers">Memory Use Markers</a>
277 <ol>
278 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
279 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
280 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
281 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
282 </ol>
283 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]284 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]285 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]286 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]287 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]288 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]289 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]290 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]291 '<tt>llvm.trap</tt>' Intrinsic</a></li>
292 <li><a href="#int_stackprotector">
293 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]294 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]295 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]296 </ol>
297 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]298</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]299
300<div class="doc_author">
301 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
302 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]303</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]304
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]305<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]306<div class="doc_section"> <a name="abstract">Abstract </a></div>
307<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]308
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]309<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]310
311<p>This document is a reference manual for the LLVM assembly language. LLVM is
312 a Static Single Assignment (SSA) based representation that provides type
313 safety, low-level operations, flexibility, and the capability of representing
314 'all' high-level languages cleanly. It is the common code representation
315 used throughout all phases of the LLVM compilation strategy.</p>
316
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]317</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]318
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]319<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]320<div class="doc_section"> <a name="introduction">Introduction</a> </div>
321<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]322
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]323<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]325<p>The LLVM code representation is designed to be used in three different forms:
326 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
327 for fast loading by a Just-In-Time compiler), and as a human readable
328 assembly language representation. This allows LLVM to provide a powerful
329 intermediate representation for efficient compiler transformations and
330 analysis, while providing a natural means to debug and visualize the
331 transformations. The three different forms of LLVM are all equivalent. This
332 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]333
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]334<p>The LLVM representation aims to be light-weight and low-level while being
335 expressive, typed, and extensible at the same time. It aims to be a
336 "universal IR" of sorts, by being at a low enough level that high-level ideas
337 may be cleanly mapped to it (similar to how microprocessors are "universal
338 IR's", allowing many source languages to be mapped to them). By providing
339 type information, LLVM can be used as the target of optimizations: for
340 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]341 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]342 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]343
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]344</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]345
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]346<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]347<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]348
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]349<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]350
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]351<p>It is important to note that this document describes 'well formed' LLVM
352 assembly language. There is a difference between what the parser accepts and
353 what is considered 'well formed'. For example, the following instruction is
354 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]355
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]356<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]357<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]358%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]359</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]360</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]361
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]362<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
363 LLVM infrastructure provides a verification pass that may be used to verify
364 that an LLVM module is well formed. This pass is automatically run by the
365 parser after parsing input assembly and by the optimizer before it outputs
366 bitcode. The violations pointed out by the verifier pass indicate bugs in
367 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]368
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]369</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]370
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]371<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]372
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]373<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]374<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]375<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]376
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]377<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]378
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]379<p>LLVM identifiers come in two basic types: global and local. Global
380 identifiers (functions, global variables) begin with the <tt>'@'</tt>
381 character. Local identifiers (register names, types) begin with
382 the <tt>'%'</tt> character. Additionally, there are three different formats
383 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]384
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]385<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]386 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]387 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
388 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
389 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
390 other characters in their names can be surrounded with quotes. Special
391 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
392 ASCII code for the character in hexadecimal. In this way, any character
393 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]394
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]395 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]396 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]397
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]398 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]399 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]400</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]401
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]402<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]403 don't need to worry about name clashes with reserved words, and the set of
404 reserved words may be expanded in the future without penalty. Additionally,
405 unnamed identifiers allow a compiler to quickly come up with a temporary
406 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]407
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]408<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]409 languages. There are keywords for different opcodes
410 ('<tt><a href="#i_add">add</a></tt>',
411 '<tt><a href="#i_bitcast">bitcast</a></tt>',
412 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
413 ('<tt><a href="#t_void">void</a></tt>',
414 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
415 reserved words cannot conflict with variable names, because none of them
416 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]417
418<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]419 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]420
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]421<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]422
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]423<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]424<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]425%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]427</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]428
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]429<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]430
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]432<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]433%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]434</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]435</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]436
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]437<p>And the hard 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>
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]441%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
442%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]443%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]445</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]447<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
448 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]449
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]450<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]451 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]452 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]453
454 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]455 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]457 <li>Unnamed temporaries are numbered sequentially</li>
458</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]460<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]461 demonstrating instructions, we will follow an instruction with a comment that
462 defines the type and name of value produced. Comments are shown in italic
463 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]465</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]466
467<!-- *********************************************************************** -->
468<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
469<!-- *********************************************************************** -->
470
471<!-- ======================================================================= -->
472<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
473</div>
474
475<div class="doc_text">
476
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]477<p>LLVM programs are composed of "Module"s, each of which is a translation unit
478 of the input programs. Each module consists of functions, global variables,
479 and symbol table entries. Modules may be combined together with the LLVM
480 linker, which merges function (and global variable) definitions, resolves
481 forward declarations, and merges symbol table entries. Here is an example of
482 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]483
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]484<div class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]485<pre>
486<i>; Declare the string constant as a global constant.</i>
487<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]488
489<i>; External declaration of the puts function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]490<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491
492<i>; Definition of main function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]493define i32 @main() { <i>; i32()* </i>
494 <i>; Convert [13 x i8]* to i8 *...</i>
495 %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]496
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]497 <i>; Call puts function to write out the string to stdout.</i>
498 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
499 <a href="#i_ret">ret</a> i32 0<br>}<br>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]500</pre>
501</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]503<p>This example is made up of a <a href="#globalvars">global variable</a> named
504 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
505 a <a href="#functionstructure">function definition</a> for
506 "<tt>main</tt>".</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]507
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]508<p>In general, a module is made up of a list of global values, where both
509 functions and global variables are global values. Global values are
510 represented by a pointer to a memory location (in this case, a pointer to an
511 array of char, and a pointer to a function), and have one of the
512 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]513
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]514</div>
515
516<!-- ======================================================================= -->
517<div class="doc_subsection">
518 <a name="linkage">Linkage Types</a>
519</div>
520
521<div class="doc_text">
522
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523<p>All Global Variables and Functions have one of the following types of
524 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]525
526<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]527 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]528 <dd>Global values with private linkage are only directly accessible by objects
529 in the current module. In particular, linking code into a module with an
530 private global value may cause the private to be renamed as necessary to
531 avoid collisions. Because the symbol is private to the module, all
532 references can be updated. This doesn't show up in any symbol table in the
533 object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]534
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]535 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]536 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere7f064e2009-08-24 04:32:16 +0000[diff] [blame]537 removed by the linker after evaluation. Note that (unlike private
538 symbols) linker_private symbols are subject to coalescing by the linker:
539 weak symbols get merged and redefinitions are rejected. However, unlike
540 normal strong symbols, they are removed by the linker from the final
541 linked image (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]542
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]543 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]544 <dd>Similar to private, but the value shows as a local symbol
545 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
546 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]547
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]549 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]550 into the object file corresponding to the LLVM module. They exist to
551 allow inlining and other optimizations to take place given knowledge of
552 the definition of the global, which is known to be somewhere outside the
553 module. Globals with <tt>available_externally</tt> linkage are allowed to
554 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
555 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]556
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]557 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]558 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]559 the same name when linkage occurs. This is typically used to implement
560 inline functions, templates, or other code which must be generated in each
561 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
562 allowed to be discarded.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]563
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]564 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]565 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
566 <tt>linkonce</tt> linkage, except that unreferenced globals with
567 <tt>weak</tt> linkage may not be discarded. This is used for globals that
568 are declared "weak" in C source code.</dd>
569
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]570 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]571 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
572 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
573 global scope.
574 Symbols with "<tt>common</tt>" linkage are merged in the same way as
575 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]576 <tt>common</tt> symbols may not have an explicit section,
577 must have a zero initializer, and may not be marked '<a
578 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
579 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]580
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]581
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]582 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]583 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]584 pointer to array type. When two global variables with appending linkage
585 are linked together, the two global arrays are appended together. This is
586 the LLVM, typesafe, equivalent of having the system linker append together
587 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]588
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]589 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]590 <dd>The semantics of this linkage follow the ELF object file model: the symbol
591 is weak until linked, if not linked, the symbol becomes null instead of
592 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]593
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]594 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
595 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]596 <dd>Some languages allow differing globals to be merged, such as two functions
597 with different semantics. Other languages, such as <tt>C++</tt>, ensure
598 that only equivalent globals are ever merged (the "one definition rule" -
599 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
600 and <tt>weak_odr</tt> linkage types to indicate that the global will only
601 be merged with equivalent globals. These linkage types are otherwise the
602 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]603
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]604 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]605 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]606 visible, meaning that it participates in linkage and can be used to
607 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]608</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]609
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]610<p>The next two types of linkage are targeted for Microsoft Windows platform
611 only. They are designed to support importing (exporting) symbols from (to)
612 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]613
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]614<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]615 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]616 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]617 or variable via a global pointer to a pointer that is set up by the DLL
618 exporting the symbol. On Microsoft Windows targets, the pointer name is
619 formed by combining <code>__imp_</code> and the function or variable
620 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]621
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]622 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]623 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]624 pointer to a pointer in a DLL, so that it can be referenced with the
625 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
626 name is formed by combining <code>__imp_</code> and the function or
627 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]628</dl>
629
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]630<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
631 another module defined a "<tt>.LC0</tt>" variable and was linked with this
632 one, one of the two would be renamed, preventing a collision. Since
633 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
634 declarations), they are accessible outside of the current module.</p>
635
636<p>It is illegal for a function <i>declaration</i> to have any linkage type
637 other than "externally visible", <tt>dllimport</tt>
638 or <tt>extern_weak</tt>.</p>
639
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]640<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]641 or <tt>weak_odr</tt> linkages.</p>
642
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]643</div>
644
645<!-- ======================================================================= -->
646<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]647 <a name="callingconv">Calling Conventions</a>
648</div>
649
650<div class="doc_text">
651
652<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]653 and <a href="#i_invoke">invokes</a> can all have an optional calling
654 convention specified for the call. The calling convention of any pair of
655 dynamic caller/callee must match, or the behavior of the program is
656 undefined. The following calling conventions are supported by LLVM, and more
657 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]658
659<dl>
660 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]661 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]662 specified) matches the target C calling conventions. This calling
663 convention supports varargs function calls and tolerates some mismatch in
664 the declared prototype and implemented declaration of the function (as
665 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]666
667 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]668 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]669 (e.g. by passing things in registers). This calling convention allows the
670 target to use whatever tricks it wants to produce fast code for the
671 target, without having to conform to an externally specified ABI
672 (Application Binary Interface). Implementations of this convention should
673 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
674 optimization</a> to be supported. This calling convention does not
675 support varargs and requires the prototype of all callees to exactly match
676 the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]677
678 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]679 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]680 as possible under the assumption that the call is not commonly executed.
681 As such, these calls often preserve all registers so that the call does
682 not break any live ranges in the caller side. This calling convention
683 does not support varargs and requires the prototype of all callees to
684 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]685
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]686 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]687 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]688 target-specific calling conventions to be used. Target specific calling
689 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]690</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]691
692<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]693 support Pascal conventions or any other well-known target-independent
694 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]695
696</div>
697
698<!-- ======================================================================= -->
699<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]700 <a name="visibility">Visibility Styles</a>
701</div>
702
703<div class="doc_text">
704
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]705<p>All Global Variables and Functions have one of the following visibility
706 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]707
708<dl>
709 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]710 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]711 that the declaration is visible to other modules and, in shared libraries,
712 means that the declared entity may be overridden. On Darwin, default
713 visibility means that the declaration is visible to other modules. Default
714 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]715
716 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]717 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]718 object if they are in the same shared object. Usually, hidden visibility
719 indicates that the symbol will not be placed into the dynamic symbol
720 table, so no other module (executable or shared library) can reference it
721 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]722
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]723 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]724 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]725 the dynamic symbol table, but that references within the defining module
726 will bind to the local symbol. That is, the symbol cannot be overridden by
727 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]728</dl>
729
730</div>
731
732<!-- ======================================================================= -->
733<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]734 <a name="namedtypes">Named Types</a>
735</div>
736
737<div class="doc_text">
738
739<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]740 it easier to read the IR and make the IR more condensed (particularly when
741 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]742
743<div class="doc_code">
744<pre>
745%mytype = type { %mytype*, i32 }
746</pre>
747</div>
748
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]749<p>You may give a name to any <a href="#typesystem">type</a> except
750 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
751 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]752
753<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]754 and that you can therefore specify multiple names for the same type. This
755 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
756 uses structural typing, the name is not part of the type. When printing out
757 LLVM IR, the printer will pick <em>one name</em> to render all types of a
758 particular shape. This means that if you have code where two different
759 source types end up having the same LLVM type, that the dumper will sometimes
760 print the "wrong" or unexpected type. This is an important design point and
761 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]762
763</div>
764
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]765<!-- ======================================================================= -->
766<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]767 <a name="globalvars">Global Variables</a>
768</div>
769
770<div class="doc_text">
771
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]772<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]773 instead of run-time. Global variables may optionally be initialized, may
774 have an explicit section to be placed in, and may have an optional explicit
775 alignment specified. A variable may be defined as "thread_local", which
776 means that it will not be shared by threads (each thread will have a
777 separated copy of the variable). A variable may be defined as a global
778 "constant," which indicates that the contents of the variable
779 will <b>never</b> be modified (enabling better optimization, allowing the
780 global data to be placed in the read-only section of an executable, etc).
781 Note that variables that need runtime initialization cannot be marked
782 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]783
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]784<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
785 constant, even if the final definition of the global is not. This capability
786 can be used to enable slightly better optimization of the program, but
787 requires the language definition to guarantee that optimizations based on the
788 'constantness' are valid for the translation units that do not include the
789 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]790
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]791<p>As SSA values, global variables define pointer values that are in scope
792 (i.e. they dominate) all basic blocks in the program. Global variables
793 always define a pointer to their "content" type because they describe a
794 region of memory, and all memory objects in LLVM are accessed through
795 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]796
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]797<p>A global variable may be declared to reside in a target-specific numbered
798 address space. For targets that support them, address spaces may affect how
799 optimizations are performed and/or what target instructions are used to
800 access the variable. The default address space is zero. The address space
801 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]802
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]803<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]804 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]805
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]806<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]807 the alignment is set to zero, the alignment of the global is set by the
808 target to whatever it feels convenient. If an explicit alignment is
809 specified, the global is forced to have at least that much alignment. All
810 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]811
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]812<p>For example, the following defines a global in a numbered address space with
813 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]814
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]815<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]816<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]817@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]818</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]819</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]820
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]821</div>
822
823
824<!-- ======================================================================= -->
825<div class="doc_subsection">
826 <a name="functionstructure">Functions</a>
827</div>
828
829<div class="doc_text">
830
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]831<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
832 optional <a href="#linkage">linkage type</a>, an optional
833 <a href="#visibility">visibility style</a>, an optional
834 <a href="#callingconv">calling convention</a>, a return type, an optional
835 <a href="#paramattrs">parameter attribute</a> for the return type, a function
836 name, a (possibly empty) argument list (each with optional
837 <a href="#paramattrs">parameter attributes</a>), optional
838 <a href="#fnattrs">function attributes</a>, an optional section, an optional
839 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
840 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]841
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]842<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
843 optional <a href="#linkage">linkage type</a>, an optional
844 <a href="#visibility">visibility style</a>, an optional
845 <a href="#callingconv">calling convention</a>, a return type, an optional
846 <a href="#paramattrs">parameter attribute</a> for the return type, a function
847 name, a possibly empty list of arguments, an optional alignment, and an
848 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]849
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]850<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]851 (Control Flow Graph) for the function. Each basic block may optionally start
852 with a label (giving the basic block a symbol table entry), contains a list
853 of instructions, and ends with a <a href="#terminators">terminator</a>
854 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]855
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]856<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]857 executed on entrance to the function, and it is not allowed to have
858 predecessor basic blocks (i.e. there can not be any branches to the entry
859 block of a function). Because the block can have no predecessors, it also
860 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]861
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]862<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]863 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]864
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]865<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]866 the alignment is set to zero, the alignment of the function is set by the
867 target to whatever it feels convenient. If an explicit alignment is
868 specified, the function is forced to have at least that much alignment. All
869 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]870
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]871<h5>Syntax:</h5>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]872<div class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]873<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]874define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]875 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
876 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
877 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
878 [<a href="#gc">gc</a>] { ... }
879</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]880</div>
881
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]882</div>
883
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]884<!-- ======================================================================= -->
885<div class="doc_subsection">
886 <a name="aliasstructure">Aliases</a>
887</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]888
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]889<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]890
891<p>Aliases act as "second name" for the aliasee value (which can be either
892 function, global variable, another alias or bitcast of global value). Aliases
893 may have an optional <a href="#linkage">linkage type</a>, and an
894 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]895
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]896<h5>Syntax:</h5>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]897<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]898<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]899@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]900</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]901</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]902
903</div>
904
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]905<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]906<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]907
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]908<div class="doc_text">
909
910<p>The return type and each parameter of a function type may have a set of
911 <i>parameter attributes</i> associated with them. Parameter attributes are
912 used to communicate additional information about the result or parameters of
913 a function. Parameter attributes are considered to be part of the function,
914 not of the function type, so functions with different parameter attributes
915 can have the same function type.</p>
916
917<p>Parameter attributes are simple keywords that follow the type specified. If
918 multiple parameter attributes are needed, they are space separated. For
919 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]920
921<div class="doc_code">
922<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]923declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]924declare i32 @atoi(i8 zeroext)
925declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]926</pre>
927</div>
928
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]929<p>Note that any attributes for the function result (<tt>nounwind</tt>,
930 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]931
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]932<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]933
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]934<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]935 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]936 <dd>This indicates to the code generator that the parameter or return value
937 should be zero-extended to a 32-bit value by the caller (for a parameter)
938 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]939
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]940 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]941 <dd>This indicates to the code generator that the parameter or return value
942 should be sign-extended to a 32-bit value by the caller (for a parameter)
943 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]944
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]945 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]946 <dd>This indicates that this parameter or return value should be treated in a
947 special target-dependent fashion during while emitting code for a function
948 call or return (usually, by putting it in a register as opposed to memory,
949 though some targets use it to distinguish between two different kinds of
950 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]951
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]952 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]953 <dd>This indicates that the pointer parameter should really be passed by value
954 to the function. The attribute implies that a hidden copy of the pointee
955 is made between the caller and the callee, so the callee is unable to
956 modify the value in the callee. This attribute is only valid on LLVM
957 pointer arguments. It is generally used to pass structs and arrays by
958 value, but is also valid on pointers to scalars. The copy is considered
959 to belong to the caller not the callee (for example,
960 <tt><a href="#readonly">readonly</a></tt> functions should not write to
961 <tt>byval</tt> parameters). This is not a valid attribute for return
962 values. The byval attribute also supports specifying an alignment with
963 the align attribute. This has a target-specific effect on the code
964 generator that usually indicates a desired alignment for the synthesized
965 stack slot.</dd>
966
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]967 <dt><tt><b>sret</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]968 <dd>This indicates that the pointer parameter specifies the address of a
969 structure that is the return value of the function in the source program.
970 This pointer must be guaranteed by the caller to be valid: loads and
971 stores to the structure may be assumed by the callee to not to trap. This
972 may only be applied to the first parameter. This is not a valid attribute
973 for return values. </dd>
974
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]975 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]976 <dd>This indicates that the pointer does not alias any global or any other
977 parameter. The caller is responsible for ensuring that this is the
978 case. On a function return value, <tt>noalias</tt> additionally indicates
979 that the pointer does not alias any other pointers visible to the
980 caller. For further details, please see the discussion of the NoAlias
981 response in
982 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
983 analysis</a>.</dd>
984
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]985 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]986 <dd>This indicates that the callee does not make any copies of the pointer
987 that outlive the callee itself. This is not a valid attribute for return
988 values.</dd>
989
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]990 <dt><tt><b>nest</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]991 <dd>This indicates that the pointer parameter can be excised using the
992 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
993 attribute for return values.</dd>
994</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]995
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]996</div>
997
998<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]999<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1000 <a name="gc">Garbage Collector Names</a>
1001</div>
1002
1003<div class="doc_text">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1004
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1005<p>Each function may specify a garbage collector name, which is simply a
1006 string:</p>
1007
1008<div class="doc_code">
1009<pre>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1010define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1011</pre>
1012</div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1013
1014<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1015 collector which will cause the compiler to alter its output in order to
1016 support the named garbage collection algorithm.</p>
1017
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1018</div>
1019
1020<!-- ======================================================================= -->
1021<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1022 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1023</div>
1024
1025<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1026
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1027<p>Function attributes are set to communicate additional information about a
1028 function. Function attributes are considered to be part of the function, not
1029 of the function type, so functions with different parameter attributes can
1030 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1031
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1032<p>Function attributes are simple keywords that follow the type specified. If
1033 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1034
1035<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1036<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1037define void @f() noinline { ... }
1038define void @f() alwaysinline { ... }
1039define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1040define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1041</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1042</div>
1043
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1044<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1045 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1046 <dd>This attribute indicates that the inliner should attempt to inline this
1047 function into callers whenever possible, ignoring any active inlining size
1048 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1049
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1050 <dt><tt><b>inlinehint</b></tt></dt>
Dale Johannesen2aaf5392009-08-26 01:08:21 +0000[diff] [blame]1051 <dd>This attribute indicates that the source code contained a hint that inlining
1052 this function is desirable (such as the "inline" keyword in C/C++). It
1053 is just a hint; it imposes no requirements on the inliner.</dd>
1054
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1055 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1056 <dd>This attribute indicates that the inliner should never inline this
1057 function in any situation. This attribute may not be used together with
1058 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1059
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1060 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1061 <dd>This attribute suggests that optimization passes and code generator passes
1062 make choices that keep the code size of this function low, and otherwise
1063 do optimizations specifically to reduce code size.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1064
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1065 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1066 <dd>This function attribute indicates that the function never returns
1067 normally. This produces undefined behavior at runtime if the function
1068 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1069
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1070 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1071 <dd>This function attribute indicates that the function never returns with an
1072 unwind or exceptional control flow. If the function does unwind, its
1073 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1074
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1075 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1076 <dd>This attribute indicates that the function computes its result (or decides
1077 to unwind an exception) based strictly on its arguments, without
1078 dereferencing any pointer arguments or otherwise accessing any mutable
1079 state (e.g. memory, control registers, etc) visible to caller functions.
1080 It does not write through any pointer arguments
1081 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1082 changes any state visible to callers. This means that it cannot unwind
1083 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1084 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1085
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1086 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1087 <dd>This attribute indicates that the function does not write through any
1088 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1089 arguments) or otherwise modify any state (e.g. memory, control registers,
1090 etc) visible to caller functions. It may dereference pointer arguments
1091 and read state that may be set in the caller. A readonly function always
1092 returns the same value (or unwinds an exception identically) when called
1093 with the same set of arguments and global state. It cannot unwind an
1094 exception by calling the <tt>C++</tt> exception throwing methods, but may
1095 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1096
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1097 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1098 <dd>This attribute indicates that the function should emit a stack smashing
1099 protector. It is in the form of a "canary"&mdash;a random value placed on
1100 the stack before the local variables that's checked upon return from the
1101 function to see if it has been overwritten. A heuristic is used to
1102 determine if a function needs stack protectors or not.<br>
1103<br>
1104 If a function that has an <tt>ssp</tt> attribute is inlined into a
1105 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1106 function will have an <tt>ssp</tt> attribute.</dd>
1107
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1108 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1109 <dd>This attribute indicates that the function should <em>always</em> emit a
1110 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1111 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1112<br>
1113 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1114 function that doesn't have an <tt>sspreq</tt> attribute or which has
1115 an <tt>ssp</tt> attribute, then the resulting function will have
1116 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1117
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1118 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1119 <dd>This attribute indicates that the code generator should not use a red
1120 zone, even if the target-specific ABI normally permits it.</dd>
1121
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1122 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1123 <dd>This attributes disables implicit floating point instructions.</dd>
1124
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1125 <dt><tt><b>naked</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1126 <dd>This attribute disables prologue / epilogue emission for the function.
1127 This can have very system-specific consequences.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1128</dl>
1129
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1130</div>
1131
1132<!-- ======================================================================= -->
1133<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1134 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1135</div>
1136
1137<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1138
1139<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1140 the GCC "file scope inline asm" blocks. These blocks are internally
1141 concatenated by LLVM and treated as a single unit, but may be separated in
1142 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1143
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1144<div class="doc_code">
1145<pre>
1146module asm "inline asm code goes here"
1147module asm "more can go here"
1148</pre>
1149</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1150
1151<p>The strings can contain any character by escaping non-printable characters.
1152 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]1153 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1154
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1155<p>The inline asm code is simply printed to the machine code .s file when
1156 assembly code is generated.</p>
1157
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1158</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1159
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1160<!-- ======================================================================= -->
1161<div class="doc_subsection">
1162 <a name="datalayout">Data Layout</a>
1163</div>
1164
1165<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1166
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1167<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1168 data is to be laid out in memory. The syntax for the data layout is
1169 simply:</p>
1170
1171<div class="doc_code">
1172<pre>
1173target datalayout = "<i>layout specification</i>"
1174</pre>
1175</div>
1176
1177<p>The <i>layout specification</i> consists of a list of specifications
1178 separated by the minus sign character ('-'). Each specification starts with
1179 a letter and may include other information after the letter to define some
1180 aspect of the data layout. The specifications accepted are as follows:</p>
1181
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1182<dl>
1183 <dt><tt>E</tt></dt>
1184 <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]1185 bits with the most significance have the lowest address location.</dd>
1186
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1187 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1188 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1189 the bits with the least significance have the lowest address
1190 location.</dd>
1191
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1192 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1193 <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]1194 <i>preferred</i> alignments. All sizes are in bits. Specifying
1195 the <i>pref</i> alignment is optional. If omitted, the
1196 preceding <tt>:</tt> should be omitted too.</dd>
1197
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1198 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1199 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1200 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1201
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1202 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1203 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1204 <i>size</i>.</dd>
1205
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1206 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1207 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1208 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1209 (double).</dd>
1210
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1211 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1212 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1213 <i>size</i>.</dd>
1214
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1215 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1216 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1217 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1218
1219 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1220 <dd>This specifies a set of native integer widths for the target CPU
1221 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1222 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
1223 this set are considered to support most general arithmetic
1224 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1225</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1226
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1227<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1228 default set of specifications which are then (possibly) overriden by the
1229 specifications in the <tt>datalayout</tt> keyword. The default specifications
1230 are given in this list:</p>
1231
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1232<ul>
1233 <li><tt>E</tt> - big endian</li>
1234 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1235 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1236 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1237 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1238 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1239 <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]1240 alignment of 64-bits</li>
1241 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1242 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1243 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1244 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1245 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1246 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1247</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1248
1249<p>When LLVM is determining the alignment for a given type, it uses the
1250 following rules:</p>
1251
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1252<ol>
1253 <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]1254 specification is used.</li>
1255
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1256 <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]1257 smallest integer type that is larger than the bitwidth of the sought type
1258 is used. If none of the specifications are larger than the bitwidth then
1259 the the largest integer type is used. For example, given the default
1260 specifications above, the i7 type will use the alignment of i8 (next
1261 largest) while both i65 and i256 will use the alignment of i64 (largest
1262 specified).</li>
1263
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1264 <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]1265 largest vector type that is smaller than the sought vector type will be
1266 used as a fall back. This happens because &lt;128 x double&gt; can be
1267 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1268</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1269
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1270</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1271
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1272<!-- ======================================================================= -->
1273<div class="doc_subsection">
1274 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1275</div>
1276
1277<div class="doc_text">
1278
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1279<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1280with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1281is undefined. Pointer values are associated with address ranges
1282according to the following rules:</p>
1283
1284<ul>
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1285 <li>A pointer value formed from a
1286 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1287 is associated with the addresses associated with the first operand
1288 of the <tt>getelementptr</tt>.</li>
1289 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1290 range of the variable's storage.</li>
1291 <li>The result value of an allocation instruction is associated with
1292 the address range of the allocated storage.</li>
1293 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1294 no address.</li>
1295 <li>A pointer value formed by an
1296 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1297 address ranges of all pointer values that contribute (directly or
1298 indirectly) to the computation of the pointer's value.</li>
1299 <li>The result value of a
1300 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1301 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1302 <li>An integer constant other than zero or a pointer value returned
1303 from a function not defined within LLVM may be associated with address
1304 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1305 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1306 allocated by mechanisms provided by LLVM.</li>
1307 </ul>
1308
1309<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1310<tt><a href="#i_load">load</a></tt> merely indicates the size and
1311alignment of the memory from which to load, as well as the
1312interpretation of the value. The first operand of a
1313<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1314and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1315
1316<p>Consequently, type-based alias analysis, aka TBAA, aka
1317<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1318LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1319additional information which specialized optimization passes may use
1320to implement type-based alias analysis.</p>
1321
1322</div>
1323
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1324<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1325<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1326<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1327
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1328<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1329
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1330<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1331 intermediate representation. Being typed enables a number of optimizations
1332 to be performed on the intermediate representation directly, without having
1333 to do extra analyses on the side before the transformation. A strong type
1334 system makes it easier to read the generated code and enables novel analyses
1335 and transformations that are not feasible to perform on normal three address
1336 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1337
1338</div>
1339
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1340<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1341<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1342Classifications</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1343
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1344<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1345
1346<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1347
1348<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1349 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1350 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1351 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1352 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1353 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1354 </tr>
1355 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1356 <td><a href="#t_floating">floating point</a></td>
1357 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1358 </tr>
1359 <tr>
1360 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1361 <td><a href="#t_integer">integer</a>,
1362 <a href="#t_floating">floating point</a>,
1363 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1364 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1365 <a href="#t_struct">structure</a>,
1366 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1367 <a href="#t_label">label</a>,
1368 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1369 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1370 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1371 <tr>
1372 <td><a href="#t_primitive">primitive</a></td>
1373 <td><a href="#t_label">label</a>,
1374 <a href="#t_void">void</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1375 <a href="#t_floating">floating point</a>,
1376 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1377 </tr>
1378 <tr>
1379 <td><a href="#t_derived">derived</a></td>
1380 <td><a href="#t_integer">integer</a>,
1381 <a href="#t_array">array</a>,
1382 <a href="#t_function">function</a>,
1383 <a href="#t_pointer">pointer</a>,
1384 <a href="#t_struct">structure</a>,
1385 <a href="#t_pstruct">packed structure</a>,
1386 <a href="#t_vector">vector</a>,
1387 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1388 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1389 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1390 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1391</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1392
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1393<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1394 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1395 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1396
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1397</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1398
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1399<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1400<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1401
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1402<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1403
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1404<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1405 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1406
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1407</div>
1408
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1409<!-- _______________________________________________________________________ -->
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1410<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1411
1412<div class="doc_text">
1413
1414<h5>Overview:</h5>
1415<p>The integer type is a very simple type that simply specifies an arbitrary
1416 bit width for the integer type desired. Any bit width from 1 bit to
1417 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1418
1419<h5>Syntax:</h5>
1420<pre>
1421 iN
1422</pre>
1423
1424<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1425 value.</p>
1426
1427<h5>Examples:</h5>
1428<table class="layout">
1429 <tr class="layout">
1430 <td class="left"><tt>i1</tt></td>
1431 <td class="left">a single-bit integer.</td>
1432 </tr>
1433 <tr class="layout">
1434 <td class="left"><tt>i32</tt></td>
1435 <td class="left">a 32-bit integer.</td>
1436 </tr>
1437 <tr class="layout">
1438 <td class="left"><tt>i1942652</tt></td>
1439 <td class="left">a really big integer of over 1 million bits.</td>
1440 </tr>
1441</table>
1442
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1443</div>
1444
1445<!-- _______________________________________________________________________ -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1446<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1447
1448<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1449
1450<table>
1451 <tbody>
1452 <tr><th>Type</th><th>Description</th></tr>
1453 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1454 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1455 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1456 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1457 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1458 </tbody>
1459</table>
1460
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1461</div>
1462
1463<!-- _______________________________________________________________________ -->
1464<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1465
1466<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1467
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1468<h5>Overview:</h5>
1469<p>The void type does not represent any value and has no size.</p>
1470
1471<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1472<pre>
1473 void
1474</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1475
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1476</div>
1477
1478<!-- _______________________________________________________________________ -->
1479<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1480
1481<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1482
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1483<h5>Overview:</h5>
1484<p>The label type represents code labels.</p>
1485
1486<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1487<pre>
1488 label
1489</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1490
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1491</div>
1492
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1493<!-- _______________________________________________________________________ -->
1494<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1495
1496<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1497
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1498<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1499<p>The metadata type represents embedded metadata. No derived types may be
1500 created from metadata except for <a href="#t_function">function</a>
1501 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1502
1503<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1504<pre>
1505 metadata
1506</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1507
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1508</div>
1509
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1510
1511<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1512<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1513
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1514<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1515
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1516<p>The real power in LLVM comes from the derived types in the system. This is
1517 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1518 useful types. Each of these types contain one or more element types which
1519 may be a primitive type, or another derived type. For example, it is
1520 possible to have a two dimensional array, using an array as the element type
1521 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1522
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1523</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1524
1525<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1526<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1527
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1528<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1529
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1530<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1531<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1532 sequentially in memory. The array type requires a size (number of elements)
1533 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1534
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1535<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1536<pre>
1537 [&lt;# elements&gt; x &lt;elementtype&gt;]
1538</pre>
1539
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1540<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1541 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1542
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1543<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1544<table class="layout">
1545 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1546 <td class="left"><tt>[40 x i32]</tt></td>
1547 <td class="left">Array of 40 32-bit integer values.</td>
1548 </tr>
1549 <tr class="layout">
1550 <td class="left"><tt>[41 x i32]</tt></td>
1551 <td class="left">Array of 41 32-bit integer values.</td>
1552 </tr>
1553 <tr class="layout">
1554 <td class="left"><tt>[4 x i8]</tt></td>
1555 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1556 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1557</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1558<p>Here are some examples of multidimensional arrays:</p>
1559<table class="layout">
1560 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1561 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1562 <td class="left">3x4 array of 32-bit integer values.</td>
1563 </tr>
1564 <tr class="layout">
1565 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1566 <td class="left">12x10 array of single precision floating point values.</td>
1567 </tr>
1568 <tr class="layout">
1569 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1570 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1571 </tr>
1572</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1573
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1574<p>There is no restriction on indexing beyond the end of the array implied by
1575 a static type (though there are restrictions on indexing beyond the bounds
1576 of an allocated object in some cases). This means that single-dimension
1577 'variable sized array' addressing can be implemented in LLVM with a zero
1578 length array type. An implementation of 'pascal style arrays' in LLVM could
1579 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1580
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1581</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1582
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1583<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1584<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1585
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1586<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1587
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1588<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1589<p>The function type can be thought of as a function signature. It consists of
1590 a return type and a list of formal parameter types. The return type of a
1591 function type is a scalar type, a void type, or a struct type. If the return
1592 type is a struct type then all struct elements must be of first class types,
1593 and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1594
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1595<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1596<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1597 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1598</pre>
1599
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1600<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]1601 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1602 which indicates that the function takes a variable number of arguments.
1603 Variable argument functions can access their arguments with
1604 the <a href="#int_varargs">variable argument handling intrinsic</a>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1605 functions. '<tt>&lt;returntype&gt;</tt>' is a any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1606 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1607
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1608<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1609<table class="layout">
1610 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1611 <td class="left"><tt>i32 (i32)</tt></td>
1612 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1613 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1614 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1615 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1616 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1617 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1618 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1619 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1620 <tt>float</tt>.
1621 </td>
1622 </tr><tr class="layout">
1623 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1624 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1625 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1626 which returns an integer. This is the signature for <tt>printf</tt> in
1627 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1628 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1629 </tr><tr class="layout">
1630 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1631 <td class="left">A function taking an <tt>i32</tt>, returning a
1632 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1633 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1634 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1635</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1636
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1637</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1638
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1639<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1640<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1641
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1642<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1643
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1644<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1645<p>The structure type is used to represent a collection of data members together
1646 in memory. The packing of the field types is defined to match the ABI of the
1647 underlying processor. The elements of a structure may be any type that has a
1648 size.</p>
1649
1650<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1651 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1652 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1653
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1654<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1655<pre>
1656 { &lt;type list&gt; }
1657</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1658
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1659<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1660<table class="layout">
1661 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1662 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1663 <td class="left">A triple of three <tt>i32</tt> values</td>
1664 </tr><tr class="layout">
1665 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1666 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1667 second element is a <a href="#t_pointer">pointer</a> to a
1668 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1669 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1670 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1671</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1672
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1673</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1674
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1675<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1676<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1677</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1678
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1679<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1680
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1681<h5>Overview:</h5>
1682<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1683 together in memory. There is no padding between fields. Further, the
1684 alignment of a packed structure is 1 byte. The elements of a packed
1685 structure may be any type that has a size.</p>
1686
1687<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1688 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1689 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1690
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1691<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1692<pre>
1693 &lt; { &lt;type list&gt; } &gt;
1694</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1695
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1696<h5>Examples:</h5>
1697<table class="layout">
1698 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1699 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1700 <td class="left">A triple of three <tt>i32</tt> values</td>
1701 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1702 <td class="left">
1703<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1704 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1705 second element is a <a href="#t_pointer">pointer</a> to a
1706 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1707 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1708 </tr>
1709</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1710
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1711</div>
1712
1713<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1714<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1715
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1716<div class="doc_text">
1717
1718<h5>Overview:</h5>
1719<p>As in many languages, the pointer type represents a pointer or reference to
1720 another object, which must live in memory. Pointer types may have an optional
1721 address space attribute defining the target-specific numbered address space
1722 where the pointed-to object resides. The default address space is zero.</p>
1723
1724<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1725 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1726
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1727<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1728<pre>
1729 &lt;type&gt; *
1730</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1731
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1732<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1733<table class="layout">
1734 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1735 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1736 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1737 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1738 </tr>
1739 <tr class="layout">
1740 <td class="left"><tt>i32 (i32 *) *</tt></td>
1741 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1742 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1743 <tt>i32</tt>.</td>
1744 </tr>
1745 <tr class="layout">
1746 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1747 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1748 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1749 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1750</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1751
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1752</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1753
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1754<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1755<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1756
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1757<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1758
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1759<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1760<p>A vector type is a simple derived type that represents a vector of elements.
1761 Vector types are used when multiple primitive data are operated in parallel
1762 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1763 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1764 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1765
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1766<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1767<pre>
1768 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1769</pre>
1770
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1771<p>The number of elements is a constant integer value; elementtype may be any
1772 integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1773
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1774<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1775<table class="layout">
1776 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1777 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1778 <td class="left">Vector of 4 32-bit integer values.</td>
1779 </tr>
1780 <tr class="layout">
1781 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1782 <td class="left">Vector of 8 32-bit floating-point values.</td>
1783 </tr>
1784 <tr class="layout">
1785 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1786 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1787 </tr>
1788</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1789
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1790</div>
1791
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1792<!-- _______________________________________________________________________ -->
1793<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1794<div class="doc_text">
1795
1796<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1797<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1798 corresponds (for example) to the C notion of a forward declared structure
1799 type. In LLVM, opaque types can eventually be resolved to any type (not just
1800 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1801
1802<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1803<pre>
1804 opaque
1805</pre>
1806
1807<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1808<table class="layout">
1809 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1810 <td class="left"><tt>opaque</tt></td>
1811 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1812 </tr>
1813</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1814
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1815</div>
1816
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1817<!-- ======================================================================= -->
1818<div class="doc_subsection">
1819 <a name="t_uprefs">Type Up-references</a>
1820</div>
1821
1822<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1823
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1824<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1825<p>An "up reference" allows you to refer to a lexically enclosing type without
1826 requiring it to have a name. For instance, a structure declaration may
1827 contain a pointer to any of the types it is lexically a member of. Example
1828 of up references (with their equivalent as named type declarations)
1829 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1830
1831<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1832 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1833 { \2 }* %y = type { %y }*
1834 \1* %z = type %z*
1835</pre>
1836
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1837<p>An up reference is needed by the asmprinter for printing out cyclic types
1838 when there is no declared name for a type in the cycle. Because the
1839 asmprinter does not want to print out an infinite type string, it needs a
1840 syntax to handle recursive types that have no names (all names are optional
1841 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1842
1843<h5>Syntax:</h5>
1844<pre>
1845 \&lt;level&gt;
1846</pre>
1847
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1848<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]1849
1850<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1851<table class="layout">
1852 <tr class="layout">
1853 <td class="left"><tt>\1*</tt></td>
1854 <td class="left">Self-referential pointer.</td>
1855 </tr>
1856 <tr class="layout">
1857 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1858 <td class="left">Recursive structure where the upref refers to the out-most
1859 structure.</td>
1860 </tr>
1861</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1862
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1863</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1864
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1865<!-- *********************************************************************** -->
1866<div class="doc_section"> <a name="constants">Constants</a> </div>
1867<!-- *********************************************************************** -->
1868
1869<div class="doc_text">
1870
1871<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1872 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1873
1874</div>
1875
1876<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1877<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1878
1879<div class="doc_text">
1880
1881<dl>
1882 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1883 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1884 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1885
1886 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1887 <dd>Standard integers (such as '4') are constants of
1888 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1889 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1890
1891 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1892 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1893 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1894 notation (see below). The assembler requires the exact decimal value of a
1895 floating-point constant. For example, the assembler accepts 1.25 but
1896 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1897 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1898
1899 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1900 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1901 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1902</dl>
1903
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1904<p>The one non-intuitive notation for constants is the hexadecimal form of
1905 floating point constants. For example, the form '<tt>double
1906 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1907 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1908 constants are required (and the only time that they are generated by the
1909 disassembler) is when a floating point constant must be emitted but it cannot
1910 be represented as a decimal floating point number in a reasonable number of
1911 digits. For example, NaN's, infinities, and other special values are
1912 represented in their IEEE hexadecimal format so that assembly and disassembly
1913 do not cause any bits to change in the constants.</p>
1914
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]1915<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1916 represented using the 16-digit form shown above (which matches the IEEE754
1917 representation for double); float values must, however, be exactly
1918 representable as IEE754 single precision. Hexadecimal format is always used
1919 for long double, and there are three forms of long double. The 80-bit format
1920 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1921 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1922 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1923 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1924 currently supported target uses this format. Long doubles will only work if
1925 they match the long double format on your target. All hexadecimal formats
1926 are big-endian (sign bit at the left).</p>
1927
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1928</div>
1929
1930<!-- ======================================================================= -->
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1931<div class="doc_subsection">
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]1932<a name="aggregateconstants"></a> <!-- old anchor -->
1933<a name="complexconstants">Complex Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1934</div>
1935
1936<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1937
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1938<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1939 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1940
1941<dl>
1942 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1943 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1944 type definitions (a comma separated list of elements, surrounded by braces
1945 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1946 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1947 Structure constants must have <a href="#t_struct">structure type</a>, and
1948 the number and types of elements must match those specified by the
1949 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1950
1951 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1952 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1953 definitions (a comma separated list of elements, surrounded by square
1954 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1955 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1956 the number and types of elements must match those specified by the
1957 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1958
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1959 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1960 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1961 definitions (a comma separated list of elements, surrounded by
1962 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1963 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1964 have <a href="#t_vector">vector type</a>, and the number and types of
1965 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1966
1967 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1968 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1969 value to zero of <em>any</em> type, including scalar and aggregate types.
1970 This is often used to avoid having to print large zero initializers
1971 (e.g. for large arrays) and is always exactly equivalent to using explicit
1972 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]1973
1974 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]1975 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1976 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1977 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1978 be interpreted as part of the instruction stream, metadata is a place to
1979 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1980</dl>
1981
1982</div>
1983
1984<!-- ======================================================================= -->
1985<div class="doc_subsection">
1986 <a name="globalconstants">Global Variable and Function Addresses</a>
1987</div>
1988
1989<div class="doc_text">
1990
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1991<p>The addresses of <a href="#globalvars">global variables</a>
1992 and <a href="#functionstructure">functions</a> are always implicitly valid
1993 (link-time) constants. These constants are explicitly referenced when
1994 the <a href="#identifiers">identifier for the global</a> is used and always
1995 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1996 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1997
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1998<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1999<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2000@X = global i32 17
2001@Y = global i32 42
2002@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2003</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2004</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2005
2006</div>
2007
2008<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]2009<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2010<div class="doc_text">
2011
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2012<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]2013 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2014 Undefined values may be of any type (other than label or void) and be used
2015 anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2016
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2017<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2018 program is well defined no matter what value is used. This gives the
2019 compiler more freedom to optimize. Here are some examples of (potentially
2020 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2021
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2022
2023<div class="doc_code">
2024<pre>
2025 %A = add %X, undef
2026 %B = sub %X, undef
2027 %C = xor %X, undef
2028Safe:
2029 %A = undef
2030 %B = undef
2031 %C = undef
2032</pre>
2033</div>
2034
2035<p>This is safe because all of the output bits are affected by the undef bits.
2036Any output bit can have a zero or one depending on the input bits.</p>
2037
2038<div class="doc_code">
2039<pre>
2040 %A = or %X, undef
2041 %B = and %X, undef
2042Safe:
2043 %A = -1
2044 %B = 0
2045Unsafe:
2046 %A = undef
2047 %B = undef
2048</pre>
2049</div>
2050
2051<p>These logical operations have bits that are not always affected by the input.
2052For example, if "%X" has a zero bit, then the output of the 'and' operation will
2053always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2054such, it is unsafe to optimize or assume that the result of the and is undef.
2055However, it is safe to assume that all bits of the undef could be 0, and
2056optimize the and to 0. Likewise, it is safe to assume that all the bits of
2057the undef operand to the or could be set, allowing the or to be folded to
2058-1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2059
2060<div class="doc_code">
2061<pre>
2062 %A = select undef, %X, %Y
2063 %B = select undef, 42, %Y
2064 %C = select %X, %Y, undef
2065Safe:
2066 %A = %X (or %Y)
2067 %B = 42 (or %Y)
2068 %C = %Y
2069Unsafe:
2070 %A = undef
2071 %B = undef
2072 %C = undef
2073</pre>
2074</div>
2075
2076<p>This set of examples show that undefined select (and conditional branch)
2077conditions can go "either way" but they have to come from one of the two
2078operands. In the %A example, if %X and %Y were both known to have a clear low
2079bit, then %A would have to have a cleared low bit. However, in the %C example,
2080the optimizer is allowed to assume that the undef operand could be the same as
2081%Y, allowing the whole select to be eliminated.</p>
2082
2083
2084<div class="doc_code">
2085<pre>
2086 %A = xor undef, undef
2087
2088 %B = undef
2089 %C = xor %B, %B
2090
2091 %D = undef
2092 %E = icmp lt %D, 4
2093 %F = icmp gte %D, 4
2094
2095Safe:
2096 %A = undef
2097 %B = undef
2098 %C = undef
2099 %D = undef
2100 %E = undef
2101 %F = undef
2102</pre>
2103</div>
2104
2105<p>This example points out that two undef operands are not necessarily the same.
2106This can be surprising to people (and also matches C semantics) where they
2107assume that "X^X" is always zero, even if X is undef. This isn't true for a
2108number of reasons, but the short answer is that an undef "variable" can
2109arbitrarily change its value over its "live range". This is true because the
2110"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2111logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2112so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner6760e542009-09-08 15:13:16 +0000[diff] [blame]2113to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2114would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2115
2116<div class="doc_code">
2117<pre>
2118 %A = fdiv undef, %X
2119 %B = fdiv %X, undef
2120Safe:
2121 %A = undef
2122b: unreachable
2123</pre>
2124</div>
2125
2126<p>These examples show the crucial difference between an <em>undefined
2127value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2128allowed to have an arbitrary bit-pattern. This means that the %A operation
2129can be constant folded to undef because the undef could be an SNaN, and fdiv is
2130not (currently) defined on SNaN's. However, in the second example, we can make
2131a more aggressive assumption: because the undef is allowed to be an arbitrary
2132value, 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]2133has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2134does not execute at all. This allows us to delete the divide and all code after
2135it: since the undefined operation "can't happen", the optimizer can assume that
2136it occurs in dead code.
2137</p>
2138
2139<div class="doc_code">
2140<pre>
2141a: store undef -> %X
2142b: store %X -> undef
2143Safe:
2144a: &lt;deleted&gt;
2145b: unreachable
2146</pre>
2147</div>
2148
2149<p>These examples reiterate the fdiv example: a store "of" an undefined value
2150can be assumed to not have any effect: we can assume that the value is
2151overwritten with bits that happen to match what was already there. However, a
2152store "to" an undefined location could clobber arbitrary memory, therefore, it
2153has undefined behavior.</p>
2154
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2155</div>
2156
2157<!-- ======================================================================= -->
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2158<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2159 Blocks</a></div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2160<div class="doc_text">
2161
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2162<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2163
2164<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2165 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2166 the address of the entry block is illegal.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2167
2168<p>This value only has defined behavior when used as an operand to the
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2169 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2170 against null. Pointer equality tests between labels addresses is undefined
2171 behavior - though, again, comparison against null is ok, and no label is
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2172 equal to the null pointer. This may also be passed around as an opaque
2173 pointer sized value as long as the bits are not inspected. This allows
Chris Lattnerda37b302009-10-27 21:44:20 +0000[diff] [blame]2174 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2175 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2176
2177<p>Finally, some targets may provide defined semantics when
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2178 using the value as the operand to an inline assembly, but that is target
2179 specific.
2180 </p>
2181
2182</div>
2183
2184
2185<!-- ======================================================================= -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2186<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2187</div>
2188
2189<div class="doc_text">
2190
2191<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2192 to be used as constants. Constant expressions may be of
2193 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2194 operation that does not have side effects (e.g. load and call are not
2195 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2196
2197<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2198 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2199 <dd>Truncate a constant to another type. The bit size of CST must be larger
2200 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2201
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2202 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2203 <dd>Zero extend a constant to another type. The bit size of CST must be
2204 smaller or equal to the bit size of TYPE. Both types must be
2205 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2206
2207 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2208 <dd>Sign extend a constant to another type. The bit size of CST must be
2209 smaller or equal to the bit size of TYPE. Both types must be
2210 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2211
2212 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2213 <dd>Truncate a floating point constant to another floating point type. The
2214 size of CST must be larger than the size of TYPE. Both types must be
2215 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2216
2217 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2218 <dd>Floating point extend a constant to another type. The size of CST must be
2219 smaller or equal to the size of TYPE. Both types must be floating
2220 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2221
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]2222 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2223 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2224 constant. TYPE must be a scalar or vector integer type. CST must be of
2225 scalar or vector floating point type. Both CST and TYPE must be scalars,
2226 or vectors of the same number of elements. If the value won't fit in the
2227 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2228
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2229 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2230 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2231 constant. TYPE must be a scalar or vector integer type. CST must be of
2232 scalar or vector floating point type. Both CST and TYPE must be scalars,
2233 or vectors of the same number of elements. If the value won't fit in the
2234 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2235
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2236 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2237 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2238 constant. TYPE must be a scalar or vector floating point type. CST must be
2239 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2240 vectors of the same number of elements. If the value won't fit in the
2241 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2242
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2243 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2244 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2245 constant. TYPE must be a scalar or vector floating point type. CST must be
2246 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2247 vectors of the same number of elements. If the value won't fit in the
2248 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2249
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2250 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2251 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2252 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2253 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2254 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2255
2256 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2257 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2258 type. CST must be of integer type. The CST value is zero extended,
2259 truncated, or unchanged to make it fit in a pointer size. This one is
2260 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2261
2262 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2263 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2264 are the same as those for the <a href="#i_bitcast">bitcast
2265 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2266
2267 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]2268 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2269 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2270 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2271 instruction, the index list may have zero or more indexes, which are
2272 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2273
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2274 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2275 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2276
2277 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2278 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2279
2280 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2281 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2282
2283 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2284 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2285 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2286
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]2287 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2288 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2289 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2290
2291 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2292 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2293 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2294
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2295 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2296 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2297 be any of the <a href="#binaryops">binary</a>
2298 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2299 on operands are the same as those for the corresponding instruction
2300 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2301</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2302
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2303</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2304
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2305<!-- ======================================================================= -->
2306<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2307</div>
2308
2309<div class="doc_text">
2310
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2311<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2312 stream without affecting the behaviour of the program. There are two
2313 metadata primitives, strings and nodes. All metadata has the
2314 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2315 point ('<tt>!</tt>').</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2316
2317<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2318 any character by escaping non-printable characters with "\xx" where "xx" is
2319 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2320
2321<p>Metadata nodes are represented with notation similar to structure constants
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2322 (a comma separated list of elements, surrounded by braces and preceded by an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2323 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2324 10}</tt>".</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2325
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2326<p>A metadata node will attempt to track changes to the values it holds. In the
2327 event that a value is deleted, it will be replaced with a typeless
2328 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckyb8f9b7a2009-05-10 20:57:05 +0000[diff] [blame]2329
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2330<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2331 the program that isn't available in the instructions, or that isn't easily
2332 computable. Similarly, the code generator may expect a certain metadata
2333 format to be used to express debugging information.</p>
2334
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2335</div>
2336
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2337<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2338<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2339<!-- *********************************************************************** -->
2340
2341<!-- ======================================================================= -->
2342<div class="doc_subsection">
2343<a name="inlineasm">Inline Assembler Expressions</a>
2344</div>
2345
2346<div class="doc_text">
2347
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2348<p>LLVM supports inline assembler expressions (as opposed
2349 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2350 a special value. This value represents the inline assembler as a string
2351 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2352 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2353 expression has side effects, and a flag indicating whether the function
2354 containing the asm needs to align its stack conservatively. An example
2355 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2356
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2357<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2358<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2359i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2360</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2361</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2362
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2363<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2364 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2365 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2366
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2367<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2368<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2369%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]2370</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2371</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2372
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2373<p>Inline asms with side effects not visible in the constraint list must be
2374 marked as having side effects. This is done through the use of the
2375 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2376
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2377<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2378<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2379call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2380</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2381</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2382
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2383<p>In some cases inline asms will contain code that will not work unless the
2384 stack is aligned in some way, such as calls or SSE instructions on x86,
2385 yet will not contain code that does that alignment within the asm.
2386 The compiler should make conservative assumptions about what the asm might
2387 contain and should generate its usual stack alignment code in the prologue
2388 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2389
2390<div class="doc_code">
2391<pre>
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2392call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2393</pre>
2394</div>
2395
2396<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2397 first.</p>
2398
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2399<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2400 documented here. Constraints on what can be done (e.g. duplication, moving,
2401 etc need to be documented). This is probably best done by reference to
2402 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2403
2404</div>
2405
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2406
2407<!-- *********************************************************************** -->
2408<div class="doc_section">
2409 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2410</div>
2411<!-- *********************************************************************** -->
2412
2413<p>LLVM has a number of "magic" global variables that contain data that affect
2414code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2415of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2416section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2417by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2418
2419<!-- ======================================================================= -->
2420<div class="doc_subsection">
2421<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2422</div>
2423
2424<div class="doc_text">
2425
2426<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2427href="#linkage_appending">appending linkage</a>. This array contains a list of
2428pointers to global variables and functions which may optionally have a pointer
2429cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2430
2431<pre>
2432 @X = global i8 4
2433 @Y = global i32 123
2434
2435 @llvm.used = appending global [2 x i8*] [
2436 i8* @X,
2437 i8* bitcast (i32* @Y to i8*)
2438 ], section "llvm.metadata"
2439</pre>
2440
2441<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2442compiler, assembler, and linker are required to treat the symbol as if there is
2443a reference to the global that it cannot see. For example, if a variable has
2444internal linkage and no references other than that from the <tt>@llvm.used</tt>
2445list, it cannot be deleted. This is commonly used to represent references from
2446inline asms and other things the compiler cannot "see", and corresponds to
2447"attribute((used))" in GNU C.</p>
2448
2449<p>On some targets, the code generator must emit a directive to the assembler or
2450object file to prevent the assembler and linker from molesting the symbol.</p>
2451
2452</div>
2453
2454<!-- ======================================================================= -->
2455<div class="doc_subsection">
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2456<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2457</div>
2458
2459<div class="doc_text">
2460
2461<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2462<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2463touching the symbol. On targets that support it, this allows an intelligent
2464linker to optimize references to the symbol without being impeded as it would be
2465by <tt>@llvm.used</tt>.</p>
2466
2467<p>This is a rare construct that should only be used in rare circumstances, and
2468should not be exposed to source languages.</p>
2469
2470</div>
2471
2472<!-- ======================================================================= -->
2473<div class="doc_subsection">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2474<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2475</div>
2476
2477<div class="doc_text">
2478
2479<p>TODO: Describe this.</p>
2480
2481</div>
2482
2483<!-- ======================================================================= -->
2484<div class="doc_subsection">
2485<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2486</div>
2487
2488<div class="doc_text">
2489
2490<p>TODO: Describe this.</p>
2491
2492</div>
2493
2494
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2495<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2496<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2497<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2498
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2499<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2500
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2501<p>The LLVM instruction set consists of several different classifications of
2502 instructions: <a href="#terminators">terminator
2503 instructions</a>, <a href="#binaryops">binary instructions</a>,
2504 <a href="#bitwiseops">bitwise binary instructions</a>,
2505 <a href="#memoryops">memory instructions</a>, and
2506 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2507
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2508</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2509
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2510<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2511<div class="doc_subsection"> <a name="terminators">Terminator
2512Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2513
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2514<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2515
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2516<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2517 in a program ends with a "Terminator" instruction, which indicates which
2518 block should be executed after the current block is finished. These
2519 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2520 control flow, not values (the one exception being the
2521 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2522
2523<p>There are six different terminator instructions: the
2524 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2525 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2526 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2527 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2528 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2529 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2530 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2531
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2532</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2533
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2534<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2535<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2536Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2537
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2538<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2539
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2540<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2541<pre>
2542 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]2543 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2544</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2545
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2546<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2547<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2548 a value) from a function back to the caller.</p>
2549
2550<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2551 value and then causes control flow, and one that just causes control flow to
2552 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2553
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2554<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2555<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2556 return value. The type of the return value must be a
2557 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2558
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2559<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2560 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2561 value or a return value with a type that does not match its type, or if it
2562 has a void return type and contains a '<tt>ret</tt>' instruction with a
2563 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2564
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2565<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2566<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2567 the calling function's context. If the caller is a
2568 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2569 instruction after the call. If the caller was an
2570 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2571 the beginning of the "normal" destination block. If the instruction returns
2572 a value, that value shall set the call or invoke instruction's return
2573 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2574
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2575<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2576<pre>
2577 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2578 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2579 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]2580</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2581
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2582</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2583<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2584<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2585
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2586<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2587
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2588<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2589<pre>
2590 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]2591</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2592
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2593<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2594<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2595 different basic block in the current function. There are two forms of this
2596 instruction, corresponding to a conditional branch and an unconditional
2597 branch.</p>
2598
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2599<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2600<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2601 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2602 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2603 target.</p>
2604
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2605<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2606<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2607 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2608 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2609 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2610
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2611<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2612<pre>
2613Test:
2614 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2615 br i1 %cond, label %IfEqual, label %IfUnequal
2616IfEqual:
2617 <a href="#i_ret">ret</a> i32 1
2618IfUnequal:
2619 <a href="#i_ret">ret</a> i32 0
2620</pre>
2621
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2622</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2623
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2624<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2625<div class="doc_subsubsection">
2626 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2627</div>
2628
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2629<div class="doc_text">
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2630
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2631<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2632<pre>
2633 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2634</pre>
2635
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2636<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2637<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]2638 several different places. It is a generalization of the '<tt>br</tt>'
2639 instruction, allowing a branch to occur to one of many possible
2640 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2641
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2642<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2643<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2644 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2645 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2646 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2647
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2648<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2649<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2650 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2651 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2652 transferred to the corresponding destination; otherwise, control flow is
2653 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2654
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2655<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2656<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2657 <tt>switch</tt> instruction, this instruction may be code generated in
2658 different ways. For example, it could be generated as a series of chained
2659 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2660
2661<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2662<pre>
2663 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2664 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2665 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2666
2667 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2668 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2669
2670 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2671 switch i32 %val, label %otherwise [ i32 0, label %onzero
2672 i32 1, label %onone
2673 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2674</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2675
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2676</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2677
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2678
2679<!-- _______________________________________________________________________ -->
2680<div class="doc_subsubsection">
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2681 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2682</div>
2683
2684<div class="doc_text">
2685
2686<h5>Syntax:</h5>
2687<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2688 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]2689</pre>
2690
2691<h5>Overview:</h5>
2692
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2693<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2694 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2695 "<tt>address</tt>". Address must be derived from a <a
2696 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2697
2698<h5>Arguments:</h5>
2699
2700<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2701 rest of the arguments indicate the full set of possible destinations that the
2702 address may point to. Blocks are allowed to occur multiple times in the
2703 destination list, though this isn't particularly useful.</p>
2704
2705<p>This destination list is required so that dataflow analysis has an accurate
2706 understanding of the CFG.</p>
2707
2708<h5>Semantics:</h5>
2709
2710<p>Control transfers to the block specified in the address argument. All
2711 possible destination blocks must be listed in the label list, otherwise this
2712 instruction has undefined behavior. This implies that jumps to labels
2713 defined in other functions have undefined behavior as well.</p>
2714
2715<h5>Implementation:</h5>
2716
2717<p>This is typically implemented with a jump through a register.</p>
2718
2719<h5>Example:</h5>
2720<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2721 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2722</pre>
2723
2724</div>
2725
2726
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2727<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2728<div class="doc_subsubsection">
2729 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2730</div>
2731
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2732<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2733
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2734<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2735<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2736 &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]2737 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2738</pre>
2739
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2740<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2741<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2742 function, with the possibility of control flow transfer to either the
2743 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2744 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2745 control flow will return to the "normal" label. If the callee (or any
2746 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2747 instruction, control is interrupted and continued at the dynamically nearest
2748 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2749
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2750<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2751<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2752
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2753<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2754 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2755 convention</a> the call should use. If none is specified, the call
2756 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2757
2758 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2759 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2760 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2761
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2762 <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]2763 function value being invoked. In most cases, this is a direct function
2764 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2765 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2766
2767 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2768 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2769
2770 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2771 signature argument types. If the function signature indicates the
2772 function accepts a variable number of arguments, the extra arguments can
2773 be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2774
2775 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2776 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2777
2778 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2779 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2780
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2781 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2782 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2783 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2784</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2785
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2786<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2787<p>This instruction is designed to operate as a standard
2788 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2789 primary difference is that it establishes an association with a label, which
2790 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2791
2792<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2793 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2794 exception. Additionally, this is important for implementation of
2795 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2796
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2797<p>For the purposes of the SSA form, the definition of the value returned by the
2798 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2799 block to the "normal" label. If the callee unwinds then no return value is
2800 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]2801
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2802<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2803<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2804 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2805 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2806 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2807 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2808</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2809
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2810</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2811
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2812<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2813
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2814<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2815Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2816
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2817<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2818
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2819<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2820<pre>
2821 unwind
2822</pre>
2823
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2824<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2825<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2826 at the first callee in the dynamic call stack which used
2827 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2828 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2829
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2830<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2831<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2832 immediately halt. The dynamic call stack is then searched for the
2833 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2834 Once found, execution continues at the "exceptional" destination block
2835 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2836 instruction in the dynamic call chain, undefined behavior results.</p>
2837
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2838</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2839
2840<!-- _______________________________________________________________________ -->
2841
2842<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2843Instruction</a> </div>
2844
2845<div class="doc_text">
2846
2847<h5>Syntax:</h5>
2848<pre>
2849 unreachable
2850</pre>
2851
2852<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2853<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2854 instruction is used to inform the optimizer that a particular portion of the
2855 code is not reachable. This can be used to indicate that the code after a
2856 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2857
2858<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2859<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2860
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2861</div>
2862
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2863<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2864<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2865
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2866<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2867
2868<p>Binary operators are used to do most of the computation in a program. They
2869 require two operands of the same type, execute an operation on them, and
2870 produce a single value. The operands might represent multiple data, as is
2871 the case with the <a href="#t_vector">vector</a> data type. The result value
2872 has the same type as its operands.</p>
2873
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2874<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2875
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2876</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2877
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2878<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2879<div class="doc_subsubsection">
2880 <a name="i_add">'<tt>add</tt>' Instruction</a>
2881</div>
2882
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2883<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2884
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2885<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2886<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2887 &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]2888 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2889 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2890 &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]2891</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2892
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2893<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2894<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2895
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2896<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2897<p>The two arguments to the '<tt>add</tt>' instruction must
2898 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2899 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2900
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2901<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2902<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2903
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2904<p>If the sum has unsigned overflow, the result returned is the mathematical
2905 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]2906
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2907<p>Because LLVM integers use a two's complement representation, this instruction
2908 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2909
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2910<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2911 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2912 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2913 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2914
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2915<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2916<pre>
2917 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
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>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2921
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2922<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2923<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2924 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2925</div>
2926
2927<div class="doc_text">
2928
2929<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2930<pre>
2931 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2932</pre>
2933
2934<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2935<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2936
2937<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2938<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2939 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2940 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2941
2942<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2943<p>The value produced is the floating point sum of the two operands.</p>
2944
2945<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2946<pre>
2947 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2948</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2949
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2950</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2951
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2952<!-- _______________________________________________________________________ -->
2953<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2954 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2955</div>
2956
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2957<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2958
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2959<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2960<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2961 &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]2962 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2963 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2964 &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]2965</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2966
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2967<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2968<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2969 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2970
2971<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2972 '<tt>neg</tt>' instruction present in most other intermediate
2973 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2974
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2975<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2976<p>The two arguments to the '<tt>sub</tt>' instruction must
2977 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2978 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2979
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2980<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2981<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2982
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2983<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2984 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2985 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2986
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2987<p>Because LLVM integers use a two's complement representation, this instruction
2988 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2989
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2990<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2991 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2992 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2993 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2994
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2995<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2996<pre>
2997 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2998 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2999</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3000
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3001</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3002
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3003<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3004<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3005 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3006</div>
3007
3008<div class="doc_text">
3009
3010<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3011<pre>
3012 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3013</pre>
3014
3015<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3016<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3017 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3018
3019<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3020 '<tt>fneg</tt>' instruction present in most other intermediate
3021 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3022
3023<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3024<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3025 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3026 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3027
3028<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3029<p>The value produced is the floating point difference of the two operands.</p>
3030
3031<h5>Example:</h5>
3032<pre>
3033 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3034 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3035</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3036
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3037</div>
3038
3039<!-- _______________________________________________________________________ -->
3040<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3041 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3042</div>
3043
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3044<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3045
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3046<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3047<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3048 &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]3049 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3050 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3051 &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]3052</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3053
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3054<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3055<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3056
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3057<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3058<p>The two arguments to the '<tt>mul</tt>' instruction must
3059 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3060 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3061
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3062<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3063<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3064
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3065<p>If the result of the multiplication has unsigned overflow, the result
3066 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3067 width of the result.</p>
3068
3069<p>Because LLVM integers use a two's complement representation, and the result
3070 is the same width as the operands, this instruction returns the correct
3071 result for both signed and unsigned integers. If a full product
3072 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3073 be sign-extended or zero-extended as appropriate to the width of the full
3074 product.</p>
3075
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3076<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3077 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3078 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
3079 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3080
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3081<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3082<pre>
3083 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3084</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3085
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3086</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3087
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3088<!-- _______________________________________________________________________ -->
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3089<div class="doc_subsubsection">
3090 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3091</div>
3092
3093<div class="doc_text">
3094
3095<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3096<pre>
3097 &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]3098</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3099
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3100<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3101<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3102
3103<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3104<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3105 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3106 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3107
3108<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3109<p>The value produced is the floating point product of the two operands.</p>
3110
3111<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3112<pre>
3113 &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]3114</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3115
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3116</div>
3117
3118<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3119<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3120</a></div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3121
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3122<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3123
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3124<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3125<pre>
3126 &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]3127</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3128
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3129<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3130<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3131
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3132<h5>Arguments:</h5>
3133<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3134 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3135 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3136
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3137<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3138<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3139
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3140<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3141 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3142
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3143<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3144
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3145<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3146<pre>
3147 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3148</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3149
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3150</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3151
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3152<!-- _______________________________________________________________________ -->
3153<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3154</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3155
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3156<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3157
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3158<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3159<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3160 &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]3161 &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]3162</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3163
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3164<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3165<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3166
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3167<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3168<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3169 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3170 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3171
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3172<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3173<p>The value produced is the signed integer quotient of the two operands rounded
3174 towards zero.</p>
3175
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3176<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3177 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3178
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3179<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3180 undefined behavior; this is a rare case, but can occur, for example, by doing
3181 a 32-bit division of -2147483648 by -1.</p>
3182
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3183<p>If the <tt>exact</tt> keyword is present, the result value of the
3184 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
3185 would occur.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3186
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3187<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3188<pre>
3189 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3190</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3191
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3192</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3193
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3194<!-- _______________________________________________________________________ -->
3195<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3196Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3197
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3198<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3199
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3200<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3201<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3202 &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]3203</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3204
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3205<h5>Overview:</h5>
3206<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3207
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3208<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3209<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3210 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3211 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3212
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3213<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3214<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3215
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3216<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3217<pre>
3218 &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]3219</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3220
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3221</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3222
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3223<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3224<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3225</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3226
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3227<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3228
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3229<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3230<pre>
3231 &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]3232</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3233
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3234<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3235<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3236 division of its two arguments.</p>
3237
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3238<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3239<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3240 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3241 values. Both arguments must have identical types.</p>
3242
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3243<h5>Semantics:</h5>
3244<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3245 This instruction always performs an unsigned division to get the
3246 remainder.</p>
3247
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3248<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3249 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3250
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3251<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3252
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3253<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3254<pre>
3255 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3256</pre>
3257
3258</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3259
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3260<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3261<div class="doc_subsubsection">
3262 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3263</div>
3264
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3265<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3266
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3267<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3268<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3269 &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]3270</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3271
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3272<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3273<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3274 division of its two operands. This instruction can also take
3275 <a href="#t_vector">vector</a> versions of the values in which case the
3276 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3277
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3278<h5>Arguments:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3279<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3280 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3281 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3282
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3283<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3284<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3285 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3286 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3287 a value. For more information about the difference,
3288 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3289 Math Forum</a>. For a table of how this is implemented in various languages,
3290 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3291 Wikipedia: modulo operation</a>.</p>
3292
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3293<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3294 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3295
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3296<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3297 Overflow also leads to undefined behavior; this is a rare case, but can
3298 occur, for example, by taking the remainder of a 32-bit division of
3299 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3300 lets srem be implemented using instructions that return both the result of
3301 the division and the remainder.)</p>
3302
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3303<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3304<pre>
3305 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3306</pre>
3307
3308</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3309
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3310<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3311<div class="doc_subsubsection">
3312 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3313
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3314<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3315
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3316<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3317<pre>
3318 &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]3319</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3320
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3321<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3322<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3323 its two operands.</p>
3324
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3325<h5>Arguments:</h5>
3326<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3327 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3328 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3329
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3330<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3331<p>This instruction returns the <i>remainder</i> of a division. The remainder
3332 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3333
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3334<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3335<pre>
3336 &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]3337</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3338
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3339</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3340
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3341<!-- ======================================================================= -->
3342<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3343Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3344
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3345<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3346
3347<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3348 program. They are generally very efficient instructions and can commonly be
3349 strength reduced from other instructions. They require two operands of the
3350 same type, execute an operation on them, and produce a single value. The
3351 resulting value is the same type as its operands.</p>
3352
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3353</div>
3354
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3355<!-- _______________________________________________________________________ -->
3356<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3357Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3358
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3359<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3360
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3361<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3362<pre>
3363 &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]3364</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3365
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3366<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3367<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3368 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3369
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3370<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3371<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3372 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3373 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3374
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3375<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3376<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3377 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3378 is (statically or dynamically) negative or equal to or larger than the number
3379 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3380 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3381 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3382
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3383<h5>Example:</h5>
3384<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3385 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3386 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3387 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3388 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3389 &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]3390</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3391
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3392</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3393
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3394<!-- _______________________________________________________________________ -->
3395<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3396Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3397
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3398<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3399
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3400<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3401<pre>
3402 &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]3403</pre>
3404
3405<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3406<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3407 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3408
3409<h5>Arguments:</h5>
3410<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3411 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3412 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3413
3414<h5>Semantics:</h5>
3415<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3416 significant bits of the result will be filled with zero bits after the shift.
3417 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3418 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3419 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3420 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3421
3422<h5>Example:</h5>
3423<pre>
3424 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3425 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3426 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3427 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3428 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3429 &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]3430</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3431
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3432</div>
3433
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3434<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3435<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3436Instruction</a> </div>
3437<div class="doc_text">
3438
3439<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3440<pre>
3441 &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]3442</pre>
3443
3444<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3445<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3446 operand shifted to the right a specified number of bits with sign
3447 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3448
3449<h5>Arguments:</h5>
3450<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3451 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3452 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3453
3454<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3455<p>This instruction always performs an arithmetic shift right operation, The
3456 most significant bits of the result will be filled with the sign bit
3457 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3458 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3459 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3460 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3461
3462<h5>Example:</h5>
3463<pre>
3464 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3465 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3466 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3467 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3468 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3469 &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]3470</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3471
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3472</div>
3473
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3474<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3475<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3476Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3477
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3478<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3479
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3480<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3481<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3482 &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]3483</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3484
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3485<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3486<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3487 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3488
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3489<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3490<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3491 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3492 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3493
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3494<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3495<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3496
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3497<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3498 <tbody>
3499 <tr>
3500 <td>In0</td>
3501 <td>In1</td>
3502 <td>Out</td>
3503 </tr>
3504 <tr>
3505 <td>0</td>
3506 <td>0</td>
3507 <td>0</td>
3508 </tr>
3509 <tr>
3510 <td>0</td>
3511 <td>1</td>
3512 <td>0</td>
3513 </tr>
3514 <tr>
3515 <td>1</td>
3516 <td>0</td>
3517 <td>0</td>
3518 </tr>
3519 <tr>
3520 <td>1</td>
3521 <td>1</td>
3522 <td>1</td>
3523 </tr>
3524 </tbody>
3525</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3526
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3527<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3528<pre>
3529 &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]3530 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3531 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3532</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3533</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3534<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3535<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3536
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3537<div class="doc_text">
3538
3539<h5>Syntax:</h5>
3540<pre>
3541 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3542</pre>
3543
3544<h5>Overview:</h5>
3545<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3546 two operands.</p>
3547
3548<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3549<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3550 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3551 values. Both arguments must have identical types.</p>
3552
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3553<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3554<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3555
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3556<table border="1" cellspacing="0" cellpadding="4">
3557 <tbody>
3558 <tr>
3559 <td>In0</td>
3560 <td>In1</td>
3561 <td>Out</td>
3562 </tr>
3563 <tr>
3564 <td>0</td>
3565 <td>0</td>
3566 <td>0</td>
3567 </tr>
3568 <tr>
3569 <td>0</td>
3570 <td>1</td>
3571 <td>1</td>
3572 </tr>
3573 <tr>
3574 <td>1</td>
3575 <td>0</td>
3576 <td>1</td>
3577 </tr>
3578 <tr>
3579 <td>1</td>
3580 <td>1</td>
3581 <td>1</td>
3582 </tr>
3583 </tbody>
3584</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3585
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3586<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3587<pre>
3588 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3589 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3590 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +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>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3594
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3595<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3596<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3597Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3598
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3599<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3600
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3601<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3602<pre>
3603 &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]3604</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3605
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3606<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3607<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3608 its two operands. The <tt>xor</tt> is used to implement the "one's
3609 complement" operation, which is the "~" operator in C.</p>
3610
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3611<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3612<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3613 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3614 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3615
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3616<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3617<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3618
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3619<table border="1" cellspacing="0" cellpadding="4">
3620 <tbody>
3621 <tr>
3622 <td>In0</td>
3623 <td>In1</td>
3624 <td>Out</td>
3625 </tr>
3626 <tr>
3627 <td>0</td>
3628 <td>0</td>
3629 <td>0</td>
3630 </tr>
3631 <tr>
3632 <td>0</td>
3633 <td>1</td>
3634 <td>1</td>
3635 </tr>
3636 <tr>
3637 <td>1</td>
3638 <td>0</td>
3639 <td>1</td>
3640 </tr>
3641 <tr>
3642 <td>1</td>
3643 <td>1</td>
3644 <td>0</td>
3645 </tr>
3646 </tbody>
3647</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3648
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3649<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3650<pre>
3651 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3652 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3653 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3654 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3655</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3656
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3657</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3658
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3659<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3660<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3661 <a name="vectorops">Vector Operations</a>
3662</div>
3663
3664<div class="doc_text">
3665
3666<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3667 target-independent manner. These instructions cover the element-access and
3668 vector-specific operations needed to process vectors effectively. While LLVM
3669 does directly support these vector operations, many sophisticated algorithms
3670 will want to use target-specific intrinsics to take full advantage of a
3671 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3672
3673</div>
3674
3675<!-- _______________________________________________________________________ -->
3676<div class="doc_subsubsection">
3677 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3678</div>
3679
3680<div class="doc_text">
3681
3682<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3683<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3684 &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]3685</pre>
3686
3687<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3688<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3689 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3690
3691
3692<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3693<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3694 of <a href="#t_vector">vector</a> type. The second operand is an index
3695 indicating the position from which to extract the element. The index may be
3696 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3697
3698<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3699<p>The result is a scalar of the same type as the element type of
3700 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3701 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3702 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3703
3704<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3705<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3706 &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]3707</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3708
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3709</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3710
3711<!-- _______________________________________________________________________ -->
3712<div class="doc_subsubsection">
3713 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3714</div>
3715
3716<div class="doc_text">
3717
3718<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3719<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3720 &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]3721</pre>
3722
3723<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3724<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3725 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3726
3727<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3728<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3729 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3730 whose type must equal the element type of the first operand. The third
3731 operand is an index indicating the position at which to insert the value.
3732 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3733
3734<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3735<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3736 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3737 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3738 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3739
3740<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3741<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3742 &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]3743</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3744
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3745</div>
3746
3747<!-- _______________________________________________________________________ -->
3748<div class="doc_subsubsection">
3749 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3750</div>
3751
3752<div class="doc_text">
3753
3754<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3755<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3756 &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]3757</pre>
3758
3759<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3760<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3761 from two input vectors, returning a vector with the same element type as the
3762 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3763
3764<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3765<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3766 with types that match each other. The third argument is a shuffle mask whose
3767 element type is always 'i32'. The result of the instruction is a vector
3768 whose length is the same as the shuffle mask and whose element type is the
3769 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3770
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3771<p>The shuffle mask operand is required to be a constant vector with either
3772 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3773
3774<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3775<p>The elements of the two input vectors are numbered from left to right across
3776 both of the vectors. The shuffle mask operand specifies, for each element of
3777 the result vector, which element of the two input vectors the result element
3778 gets. The element selector may be undef (meaning "don't care") and the
3779 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3780
3781<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3782<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3783 &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]3784 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3785 &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]3786 &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.
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3787 &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]3788 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3789 &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]3790 &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]3791</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3792
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3793</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3794
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3795<!-- ======================================================================= -->
3796<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3797 <a name="aggregateops">Aggregate Operations</a>
3798</div>
3799
3800<div class="doc_text">
3801
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3802<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3803
3804</div>
3805
3806<!-- _______________________________________________________________________ -->
3807<div class="doc_subsubsection">
3808 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3809</div>
3810
3811<div class="doc_text">
3812
3813<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3814<pre>
3815 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3816</pre>
3817
3818<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3819<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3820 or array element from an aggregate value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3821
3822<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3823<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3824 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3825 operands are constant indices to specify which value to extract in a similar
3826 manner as indices in a
3827 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3828
3829<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3830<p>The result is the value at the position in the aggregate specified by the
3831 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3832
3833<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3834<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3835 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3836</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3837
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3838</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3839
3840<!-- _______________________________________________________________________ -->
3841<div class="doc_subsubsection">
3842 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3843</div>
3844
3845<div class="doc_text">
3846
3847<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3848<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3849 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3850</pre>
3851
3852<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3853<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3854 array element in an aggregate.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3855
3856
3857<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3858<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3859 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3860 second operand is a first-class value to insert. The following operands are
3861 constant indices indicating the position at which to insert the value in a
3862 similar manner as indices in a
3863 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3864 value to insert must have the same type as the value identified by the
3865 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3866
3867<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3868<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3869 that of <tt>val</tt> except that the value at the position specified by the
3870 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3871
3872<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3873<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3874 &lt;result&gt; = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3875</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3876
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3877</div>
3878
3879
3880<!-- ======================================================================= -->
3881<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3882 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3883</div>
3884
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3885<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3886
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3887<p>A key design point of an SSA-based representation is how it represents
3888 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]3889 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3890 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3891
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3892</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3893
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3894<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3895<div class="doc_subsubsection">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3896 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3897</div>
3898
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3899<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3900
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3901<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3902<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3903 &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]3904</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3905
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3906<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3907<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3908 currently executing function, to be automatically released when this function
3909 returns to its caller. The object is always allocated in the generic address
3910 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3911
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3912<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3913<p>The '<tt>alloca</tt>' instruction
3914 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3915 runtime stack, returning a pointer of the appropriate type to the program.
3916 If "NumElements" is specified, it is the number of elements allocated,
3917 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3918 specified, the value result of the allocation is guaranteed to be aligned to
3919 at least that boundary. If not specified, or if zero, the target can choose
3920 to align the allocation on any convenient boundary compatible with the
3921 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3922
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3923<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3924
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3925<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]3926<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3927 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3928 memory is automatically released when the function returns. The
3929 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3930 variables that must have an address available. When the function returns
3931 (either with the <tt><a href="#i_ret">ret</a></tt>
3932 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3933 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3934
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3935<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3936<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3937 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3938 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3939 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3940 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3941</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3942
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3943</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3944
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3945<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3946<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3947Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3948
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3949<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3950
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3951<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3952<pre>
3953 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3954 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3955</pre>
3956
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3957<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3958<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3959
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3960<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3961<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3962 from which to load. The pointer must point to
3963 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3964 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3965 number or order of execution of this <tt>load</tt> with other
3966 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3967 instructions. </p>
3968
3969<p>The optional constant "align" argument specifies the alignment of the
3970 operation (that is, the alignment of the memory address). A value of 0 or an
3971 omitted "align" argument means that the operation has the preferential
3972 alignment for the target. It is the responsibility of the code emitter to
3973 ensure that the alignment information is correct. Overestimating the
3974 alignment results in an undefined behavior. Underestimating the alignment may
3975 produce less efficient code. An alignment of 1 is always safe.</p>
3976
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3977<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3978<p>The location of memory pointed to is loaded. If the value being loaded is of
3979 scalar type then the number of bytes read does not exceed the minimum number
3980 of bytes needed to hold all bits of the type. For example, loading an
3981 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3982 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3983 is undefined if the value was not originally written using a store of the
3984 same type.</p>
3985
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3986<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3987<pre>
3988 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3989 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3990 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3991</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3992
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3993</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3994
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3995<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3996<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3997Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3998
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3999<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4000
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4001<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4002<pre>
4003 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]4004 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4005</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4006
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4007<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4008<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4009
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4010<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4011<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4012 and an address at which to store it. The type of the
4013 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4014 the <a href="#t_firstclass">first class</a> type of the
4015 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
4016 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
4017 or order of execution of this <tt>store</tt> with other
4018 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4019 instructions.</p>
4020
4021<p>The optional constant "align" argument specifies the alignment of the
4022 operation (that is, the alignment of the memory address). A value of 0 or an
4023 omitted "align" argument means that the operation has the preferential
4024 alignment for the target. It is the responsibility of the code emitter to
4025 ensure that the alignment information is correct. Overestimating the
4026 alignment results in an undefined behavior. Underestimating the alignment may
4027 produce less efficient code. An alignment of 1 is always safe.</p>
4028
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4029<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4030<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4031 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4032 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4033 does not exceed the minimum number of bytes needed to hold all bits of the
4034 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4035 writing a value of a type like <tt>i20</tt> with a size that is not an
4036 integral number of bytes, it is unspecified what happens to the extra bits
4037 that do not belong to the type, but they will typically be overwritten.</p>
4038
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4039<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4040<pre>
4041 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4042 store i32 3, i32* %ptr <i>; yields {void}</i>
4043 %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]4044</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4045
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4046</div>
4047
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4048<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4049<div class="doc_subsubsection">
4050 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4051</div>
4052
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4053<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4054
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4055<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4056<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4057 &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]4058 &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]4059</pre>
4060
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4061<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4062<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
4063 subelement of an aggregate data structure. It performs address calculation
4064 only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4065
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4066<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4067<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4068 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4069 elements of the aggregate object are indexed. The interpretation of each
4070 index is dependent on the type being indexed into. The first index always
4071 indexes the pointer value given as the first argument, the second index
4072 indexes a value of the type pointed to (not necessarily the value directly
4073 pointed to, since the first index can be non-zero), etc. The first type
4074 indexed into must be a pointer value, subsequent types can be arrays, vectors
4075 and structs. Note that subsequent types being indexed into can never be
4076 pointers, since that would require loading the pointer before continuing
4077 calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4078
4079<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4080 When indexing into a (optionally packed) structure, only <tt>i32</tt> integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4081 <b>constants</b> are allowed. When indexing into an array, pointer or
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4082 vector, integers of any width are allowed, and they are not required to be
4083 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4084
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4085<p>For example, let's consider a C code fragment and how it gets compiled to
4086 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4087
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4088<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4089<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4090struct RT {
4091 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4092 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4093 char C;
4094};
4095struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4096 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4097 double Y;
4098 struct RT Z;
4099};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4100
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4101int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4102 return &amp;s[1].Z.B[5][13];
4103}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4104</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4105</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4106
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4107<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4108
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4109<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4110<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4111%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4112%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4113
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4114define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4115entry:
4116 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4117 ret i32* %reg
4118}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4119</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4120</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4121
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4122<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4123<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]4124 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4125 }</tt>' type, a structure. The second index indexes into the third element
4126 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4127 i8 }</tt>' type, another structure. The third index indexes into the second
4128 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4129 array. The two dimensions of the array are subscripted into, yielding an
4130 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4131 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4132
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4133<p>Note that it is perfectly legal to index partially through a structure,
4134 returning a pointer to an inner element. Because of this, the LLVM code for
4135 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4136
4137<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4138 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4139 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4140 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4141 %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]4142 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4143 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4144 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4145 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4146</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4147
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4148<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4149 <tt>getelementptr</tt> is undefined if the base pointer is not an
4150 <i>in bounds</i> address of an allocated object, or if any of the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame]4151 that would be formed by successive addition of the offsets implied by the
4152 indices to the base address with infinitely precise arithmetic are not an
4153 <i>in bounds</i> address of that allocated object.
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4154 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame]4155 that point into the object, plus the address one byte past the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4156
4157<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4158 the base address with silently-wrapping two's complement arithmetic, and
4159 the result value of the <tt>getelementptr</tt> may be outside the object
4160 pointed to by the base pointer. The result value may not necessarily be
4161 used to access memory though, even if it happens to point into allocated
4162 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4163 section for more information.</p>
4164
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4165<p>The getelementptr instruction is often confusing. For some more insight into
4166 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4167
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4168<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4169<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4170 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4171 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4172 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4173 %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]4174 <i>; yields i8*:eptr</i>
4175 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4176 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4177 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4178</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4179
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4180</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4181
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4182<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4183<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4184</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4185
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4186<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4187
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4188<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4189 which all take a single operand and a type. They perform various bit
4190 conversions on the operand.</p>
4191
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4192</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4193
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4194<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4195<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4196 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4197</div>
4198<div class="doc_text">
4199
4200<h5>Syntax:</h5>
4201<pre>
4202 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4203</pre>
4204
4205<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4206<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4207 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4208
4209<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4210<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4211 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4212 size and type of the result, which must be
4213 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4214 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4215 allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4216
4217<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4218<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4219 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4220 source size must be larger than the destination size, <tt>trunc</tt> cannot
4221 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4222
4223<h5>Example:</h5>
4224<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4225 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4226 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4227 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4228</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4229
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4230</div>
4231
4232<!-- _______________________________________________________________________ -->
4233<div class="doc_subsubsection">
4234 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4235</div>
4236<div class="doc_text">
4237
4238<h5>Syntax:</h5>
4239<pre>
4240 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4241</pre>
4242
4243<h5>Overview:</h5>
4244<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4245 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4246
4247
4248<h5>Arguments:</h5>
4249<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]4250 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4251 also be of <a href="#t_integer">integer</a> type. The bit size of the
4252 <tt>value</tt> must be smaller than the bit size of the destination type,
4253 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4254
4255<h5>Semantics:</h5>
4256<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]4257 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4258
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4259<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]4260
4261<h5>Example:</h5>
4262<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4263 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4264 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4265</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4266
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4267</div>
4268
4269<!-- _______________________________________________________________________ -->
4270<div class="doc_subsubsection">
4271 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4272</div>
4273<div class="doc_text">
4274
4275<h5>Syntax:</h5>
4276<pre>
4277 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4278</pre>
4279
4280<h5>Overview:</h5>
4281<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4282
4283<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4284<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4285 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4286 also be of <a href="#t_integer">integer</a> type. The bit size of the
4287 <tt>value</tt> must be smaller than the bit size of the destination type,
4288 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4289
4290<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4291<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4292 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4293 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4294
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4295<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]4296
4297<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4298<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4299 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4300 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4301</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4302
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4303</div>
4304
4305<!-- _______________________________________________________________________ -->
4306<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4307 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4308</div>
4309
4310<div class="doc_text">
4311
4312<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4313<pre>
4314 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4315</pre>
4316
4317<h5>Overview:</h5>
4318<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4319 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4320
4321<h5>Arguments:</h5>
4322<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4323 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4324 to cast it to. The size of <tt>value</tt> must be larger than the size of
4325 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4326 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4327
4328<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4329<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4330 <a href="#t_floating">floating point</a> type to a smaller
4331 <a href="#t_floating">floating point</a> type. If the value cannot fit
4332 within the destination type, <tt>ty2</tt>, then the results are
4333 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4334
4335<h5>Example:</h5>
4336<pre>
4337 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4338 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4339</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4340
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4341</div>
4342
4343<!-- _______________________________________________________________________ -->
4344<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4345 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4346</div>
4347<div class="doc_text">
4348
4349<h5>Syntax:</h5>
4350<pre>
4351 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4352</pre>
4353
4354<h5>Overview:</h5>
4355<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]4356 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4357
4358<h5>Arguments:</h5>
4359<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4360 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4361 a <a href="#t_floating">floating point</a> type to cast it to. The source
4362 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4363
4364<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4365<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4366 <a href="#t_floating">floating point</a> type to a larger
4367 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4368 used to make a <i>no-op cast</i> because it always changes bits. Use
4369 <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]4370
4371<h5>Example:</h5>
4372<pre>
4373 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4374 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4375</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4376
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4377</div>
4378
4379<!-- _______________________________________________________________________ -->
4380<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4381 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4382</div>
4383<div class="doc_text">
4384
4385<h5>Syntax:</h5>
4386<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4387 &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]4388</pre>
4389
4390<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4391<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4392 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4393
4394<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4395<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4396 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4397 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4398 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4399 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4400
4401<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4402<p>The '<tt>fptoui</tt>' instruction converts its
4403 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4404 towards zero) unsigned integer value. If the value cannot fit
4405 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4406
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4407<h5>Example:</h5>
4408<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4409 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4410 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4411 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4412</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4413
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4414</div>
4415
4416<!-- _______________________________________________________________________ -->
4417<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4418 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4419</div>
4420<div class="doc_text">
4421
4422<h5>Syntax:</h5>
4423<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4424 &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]4425</pre>
4426
4427<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4428<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4429 <a href="#t_floating">floating point</a> <tt>value</tt> to
4430 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4431
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4432<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4433<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4434 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4435 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4436 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4437 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4438
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4439<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4440<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4441 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4442 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4443 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4444
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4445<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4446<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4447 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4448 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4449 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4450</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4451
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4452</div>
4453
4454<!-- _______________________________________________________________________ -->
4455<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4456 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4457</div>
4458<div class="doc_text">
4459
4460<h5>Syntax:</h5>
4461<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4462 &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]4463</pre>
4464
4465<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4466<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4467 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4468
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4469<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4470<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]4471 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4472 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4473 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4474 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4475
4476<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4477<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4478 integer quantity and converts it to the corresponding floating point
4479 value. If the value cannot fit in the floating point value, the results are
4480 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4481
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4482<h5>Example:</h5>
4483<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4484 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4485 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4486</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4487
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4488</div>
4489
4490<!-- _______________________________________________________________________ -->
4491<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4492 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4493</div>
4494<div class="doc_text">
4495
4496<h5>Syntax:</h5>
4497<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4498 &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]4499</pre>
4500
4501<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4502<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4503 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4504
4505<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4506<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]4507 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4508 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4509 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4510 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4511
4512<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4513<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4514 quantity and converts it to the corresponding floating point value. If the
4515 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4516
4517<h5>Example:</h5>
4518<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4519 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4520 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4521</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4522
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4523</div>
4524
4525<!-- _______________________________________________________________________ -->
4526<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4527 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4528</div>
4529<div class="doc_text">
4530
4531<h5>Syntax:</h5>
4532<pre>
4533 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4534</pre>
4535
4536<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4537<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4538 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4539
4540<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4541<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4542 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4543 <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]4544
4545<h5>Semantics:</h5>
4546<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4547 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4548 truncating or zero extending that value to the size of the integer type. If
4549 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4550 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4551 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4552 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4553
4554<h5>Example:</h5>
4555<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4556 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4557 %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]4558</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4559
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4560</div>
4561
4562<!-- _______________________________________________________________________ -->
4563<div class="doc_subsubsection">
4564 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4565</div>
4566<div class="doc_text">
4567
4568<h5>Syntax:</h5>
4569<pre>
4570 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4571</pre>
4572
4573<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4574<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4575 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4576
4577<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4578<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4579 value to cast, and a type to cast it to, which must be a
4580 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4581
4582<h5>Semantics:</h5>
4583<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4584 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4585 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4586 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4587 than the size of a pointer then a zero extension is done. If they are the
4588 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4589
4590<h5>Example:</h5>
4591<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4592 %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]4593 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4594 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4595</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4596
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4597</div>
4598
4599<!-- _______________________________________________________________________ -->
4600<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4601 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4602</div>
4603<div class="doc_text">
4604
4605<h5>Syntax:</h5>
4606<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4607 &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]4608</pre>
4609
4610<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4611<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4612 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4613
4614<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4615<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4616 non-aggregate first class value, and a type to cast it to, which must also be
4617 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4618 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4619 identical. If the source type is a pointer, the destination type must also be
4620 a pointer. This instruction supports bitwise conversion of vectors to
4621 integers and to vectors of other types (as long as they have the same
4622 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4623
4624<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4625<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4626 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4627 this conversion. The conversion is done as if the <tt>value</tt> had been
4628 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4629 be converted to other pointer types with this instruction. To convert
4630 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4631 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4632
4633<h5>Example:</h5>
4634<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4635 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4636 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4637 %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]4638</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4639
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4640</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4641
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4642<!-- ======================================================================= -->
4643<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4644
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4645<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4646
4647<p>The instructions in this category are the "miscellaneous" instructions, which
4648 defy better classification.</p>
4649
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4650</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4651
4652<!-- _______________________________________________________________________ -->
4653<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4654</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4655
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4656<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4657
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4658<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4659<pre>
4660 &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]4661</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4662
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4663<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4664<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4665 boolean values based on comparison of its two integer, integer vector, or
4666 pointer operands.</p>
4667
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4668<h5>Arguments:</h5>
4669<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4670 the condition code indicating the kind of comparison to perform. It is not a
4671 value, just a keyword. The possible condition code are:</p>
4672
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4673<ol>
4674 <li><tt>eq</tt>: equal</li>
4675 <li><tt>ne</tt>: not equal </li>
4676 <li><tt>ugt</tt>: unsigned greater than</li>
4677 <li><tt>uge</tt>: unsigned greater or equal</li>
4678 <li><tt>ult</tt>: unsigned less than</li>
4679 <li><tt>ule</tt>: unsigned less or equal</li>
4680 <li><tt>sgt</tt>: signed greater than</li>
4681 <li><tt>sge</tt>: signed greater or equal</li>
4682 <li><tt>slt</tt>: signed less than</li>
4683 <li><tt>sle</tt>: signed less or equal</li>
4684</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4685
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4686<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4687 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4688 typed. They must also be identical types.</p>
4689
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4690<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4691<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4692 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4693 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]4694 result, as follows:</p>
4695
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4696<ol>
4697 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4698 <tt>false</tt> otherwise. No sign interpretation is necessary or
4699 performed.</li>
4700
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4701 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4702 <tt>false</tt> otherwise. No sign interpretation is necessary or
4703 performed.</li>
4704
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4705 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4706 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4707
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4708 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4709 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4710 to <tt>op2</tt>.</li>
4711
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4712 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4713 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4714
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4715 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4716 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4717
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4718 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4719 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4720
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4721 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4722 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4723 to <tt>op2</tt>.</li>
4724
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4725 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4726 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4727
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4728 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4729 <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]4730</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4731
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4732<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4733 values are compared as if they were integers.</p>
4734
4735<p>If the operands are integer vectors, then they are compared element by
4736 element. The result is an <tt>i1</tt> vector with the same number of elements
4737 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4738
4739<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4740<pre>
4741 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4742 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4743 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4744 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4745 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4746 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4747</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4748
4749<p>Note that the code generator does not yet support vector types with
4750 the <tt>icmp</tt> instruction.</p>
4751
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4752</div>
4753
4754<!-- _______________________________________________________________________ -->
4755<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4756</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4757
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4758<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4759
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4760<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4761<pre>
4762 &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]4763</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4764
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4765<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4766<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4767 values based on comparison of its operands.</p>
4768
4769<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]4770(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4771
4772<p>If the operands are floating point vectors, then the result type is a vector
4773 of boolean with the same number of elements as the operands being
4774 compared.</p>
4775
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4776<h5>Arguments:</h5>
4777<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4778 the condition code indicating the kind of comparison to perform. It is not a
4779 value, just a keyword. The possible condition code are:</p>
4780
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4781<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4782 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4783 <li><tt>oeq</tt>: ordered and equal</li>
4784 <li><tt>ogt</tt>: ordered and greater than </li>
4785 <li><tt>oge</tt>: ordered and greater than or equal</li>
4786 <li><tt>olt</tt>: ordered and less than </li>
4787 <li><tt>ole</tt>: ordered and less than or equal</li>
4788 <li><tt>one</tt>: ordered and not equal</li>
4789 <li><tt>ord</tt>: ordered (no nans)</li>
4790 <li><tt>ueq</tt>: unordered or equal</li>
4791 <li><tt>ugt</tt>: unordered or greater than </li>
4792 <li><tt>uge</tt>: unordered or greater than or equal</li>
4793 <li><tt>ult</tt>: unordered or less than </li>
4794 <li><tt>ule</tt>: unordered or less than or equal</li>
4795 <li><tt>une</tt>: unordered or not equal</li>
4796 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4797 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4798</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4799
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4800<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4801 <i>unordered</i> means that either operand may be a QNAN.</p>
4802
4803<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4804 a <a href="#t_floating">floating point</a> type or
4805 a <a href="#t_vector">vector</a> of floating point type. They must have
4806 identical types.</p>
4807
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4808<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4809<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4810 according to the condition code given as <tt>cond</tt>. If the operands are
4811 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4812 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4813 follows:</p>
4814
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4815<ol>
4816 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4817
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4818 <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]4819 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4820
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4821 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4822 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4823
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4824 <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]4825 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4826
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4827 <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]4828 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4829
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4830 <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]4831 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4832
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4833 <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]4834 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4835
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4836 <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]4837
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4838 <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]4839 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4840
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4841 <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]4842 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4843
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4844 <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]4845 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4846
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4847 <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]4848 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4849
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4850 <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]4851 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4852
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4853 <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]4854 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4855
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4856 <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]4857
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4858 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4859</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4860
4861<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4862<pre>
4863 &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]4864 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4865 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4866 &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]4867</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4868
4869<p>Note that the code generator does not yet support vector types with
4870 the <tt>fcmp</tt> instruction.</p>
4871
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4872</div>
4873
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4874<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4875<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4876 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4877</div>
4878
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4879<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4880
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4881<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4882<pre>
4883 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4884</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4885
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4886<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4887<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4888 SSA graph representing the function.</p>
4889
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4890<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4891<p>The type of the incoming values is specified with the first type field. After
4892 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4893 one pair for each predecessor basic block of the current block. Only values
4894 of <a href="#t_firstclass">first class</a> type may be used as the value
4895 arguments to the PHI node. Only labels may be used as the label
4896 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4897
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4898<p>There must be no non-phi instructions between the start of a basic block and
4899 the PHI instructions: i.e. PHI instructions must be first in a basic
4900 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4901
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4902<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4903 occur on the edge from the corresponding predecessor block to the current
4904 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4905 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]4906
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4907<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4908<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4909 specified by the pair corresponding to the predecessor basic block that
4910 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4911
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4912<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4913<pre>
4914Loop: ; Infinite loop that counts from 0 on up...
4915 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4916 %nextindvar = add i32 %indvar, 1
4917 br label %Loop
4918</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4919
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4920</div>
4921
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4922<!-- _______________________________________________________________________ -->
4923<div class="doc_subsubsection">
4924 <a name="i_select">'<tt>select</tt>' Instruction</a>
4925</div>
4926
4927<div class="doc_text">
4928
4929<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4930<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4931 &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>
4932
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4933 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4934</pre>
4935
4936<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4937<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4938 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4939
4940
4941<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4942<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4943 values indicating the condition, and two values of the
4944 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4945 vectors and the condition is a scalar, then entire vectors are selected, not
4946 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4947
4948<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4949<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4950 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4951
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4952<p>If the condition is a vector of i1, then the value arguments must be vectors
4953 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4954
4955<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4956<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4957 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4958</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4959
4960<p>Note that the code generator does not yet support conditions
4961 with vector type.</p>
4962
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4963</div>
4964
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4965<!-- _______________________________________________________________________ -->
4966<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4967 <a name="i_call">'<tt>call</tt>' Instruction</a>
4968</div>
4969
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4970<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4971
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4972<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4973<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4974 &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]4975</pre>
4976
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4977<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4978<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4979
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4980<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4981<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4982
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4983<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4984 <li>The optional "tail" marker indicates whether the callee function accesses
4985 any allocas or varargs in the caller. If the "tail" marker is present,
4986 the function call is eligible for tail call optimization. Note that calls
4987 may be marked "tail" even if they do not occur before
4988 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4989
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4990 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4991 convention</a> the call should use. If none is specified, the call
4992 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4993
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4994 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4995 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4996 '<tt>inreg</tt>' attributes are valid here.</li>
4997
4998 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4999 type of the return value. Functions that return no value are marked
5000 <tt><a href="#t_void">void</a></tt>.</li>
5001
5002 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5003 being invoked. The argument types must match the types implied by this
5004 signature. This type can be omitted if the function is not varargs and if
5005 the function type does not return a pointer to a function.</li>
5006
5007 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5008 be invoked. In most cases, this is a direct function invocation, but
5009 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5010 to function value.</li>
5011
5012 <li>'<tt>function args</tt>': argument list whose types match the function
5013 signature argument types. All arguments must be of
5014 <a href="#t_firstclass">first class</a> type. If the function signature
5015 indicates the function accepts a variable number of arguments, the extra
5016 arguments can be specified.</li>
5017
5018 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5019 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5020 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5021</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5022
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5023<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5024<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5025 a specified function, with its incoming arguments bound to the specified
5026 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5027 function, control flow continues with the instruction after the function
5028 call, and the return value of the function is bound to the result
5029 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5030
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5031<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5032<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5033 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5034 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5035 %X = tail call i32 @foo() <i>; yields i32</i>
5036 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5037 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5038
5039 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5040 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5041 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5042 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5043 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5044 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5045</pre>
5046
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5047<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5048standard C99 library as being the C99 library functions, and may perform
5049optimizations or generate code for them under that assumption. This is
5050something we'd like to change in the future to provide better support for
5051freestanding environments and non-C-based langauges.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5052
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5053</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5054
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5055<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5056<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5057 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5058</div>
5059
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5060<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5061
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5062<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5063<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5064 &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]5065</pre>
5066
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5067<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5068<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5069 the "variable argument" area of a function call. It is used to implement the
5070 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5071
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5072<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5073<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5074 argument. It returns a value of the specified argument type and increments
5075 the <tt>va_list</tt> to point to the next argument. The actual type
5076 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5077
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5078<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5079<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5080 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5081 to the next argument. For more information, see the variable argument
5082 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5083
5084<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]5085 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5086 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5087
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5088<p><tt>va_arg</tt> is an LLVM instruction instead of
5089 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5090 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5091
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5092<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5093<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5094
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5095<p>Note that the code generator does not yet fully support va_arg on many
5096 targets. Also, it does not currently support va_arg with aggregate types on
5097 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5098
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5099</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5100
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5101<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5102<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5103<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5104
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5105<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5106
5107<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5108 well known names and semantics and are required to follow certain
5109 restrictions. Overall, these intrinsics represent an extension mechanism for
5110 the LLVM language that does not require changing all of the transformations
5111 in LLVM when adding to the language (or the bitcode reader/writer, the
5112 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5113
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5114<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5115 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5116 begin with this prefix. Intrinsic functions must always be external
5117 functions: you cannot define the body of intrinsic functions. Intrinsic
5118 functions may only be used in call or invoke instructions: it is illegal to
5119 take the address of an intrinsic function. Additionally, because intrinsic
5120 functions are part of the LLVM language, it is required if any are added that
5121 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5122
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5123<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5124 family of functions that perform the same operation but on different data
5125 types. Because LLVM can represent over 8 million different integer types,
5126 overloading is used commonly to allow an intrinsic function to operate on any
5127 integer type. One or more of the argument types or the result type can be
5128 overloaded to accept any integer type. Argument types may also be defined as
5129 exactly matching a previous argument's type or the result type. This allows
5130 an intrinsic function which accepts multiple arguments, but needs all of them
5131 to be of the same type, to only be overloaded with respect to a single
5132 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5133
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5134<p>Overloaded intrinsics will have the names of its overloaded argument types
5135 encoded into its function name, each preceded by a period. Only those types
5136 which are overloaded result in a name suffix. Arguments whose type is matched
5137 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5138 can take an integer of any width and returns an integer of exactly the same
5139 integer width. This leads to a family of functions such as
5140 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5141 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5142 suffix is required. Because the argument's type is matched against the return
5143 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5144
5145<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5146 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5147
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5148</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5149
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5150<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5151<div class="doc_subsection">
5152 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5153</div>
5154
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5155<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5156
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5157<p>Variable argument support is defined in LLVM with
5158 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5159 intrinsic functions. These functions are related to the similarly named
5160 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5161
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5162<p>All of these functions operate on arguments that use a target-specific value
5163 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5164 not define what this type is, so all transformations should be prepared to
5165 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5166
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5167<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]5168 instruction and the variable argument handling intrinsic functions are
5169 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5170
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5171<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5172<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5173define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5174 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5175 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5176 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5177 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5178
5179 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5180 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5181
5182 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5183 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5184 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5185 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5186 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5187
5188 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5189 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5190 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5191}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5192
5193declare void @llvm.va_start(i8*)
5194declare void @llvm.va_copy(i8*, i8*)
5195declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5196</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5197</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5198
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5199</div>
5200
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5201<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5202<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5203 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5204</div>
5205
5206
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5207<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5208
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5209<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5210<pre>
5211 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5212</pre>
5213
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5214<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5215<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5216 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]5217
5218<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5219<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]5220
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5221<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5222<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]5223 macro available in C. In a target-dependent way, it initializes
5224 the <tt>va_list</tt> element to which the argument points, so that the next
5225 call to <tt>va_arg</tt> will produce the first variable argument passed to
5226 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5227 need to know the last argument of the function as the compiler can figure
5228 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5229
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5230</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5231
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5232<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5233<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5234 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5235</div>
5236
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5237<div class="doc_text">
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5238
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5239<h5>Syntax:</h5>
5240<pre>
5241 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5242</pre>
5243
5244<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5245<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5246 which has been initialized previously
5247 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5248 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5249
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5250<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5251<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]5252
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5253<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5254<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]5255 macro available in C. In a target-dependent way, it destroys
5256 the <tt>va_list</tt> element to which the argument points. Calls
5257 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5258 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5259 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5260
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5261</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5262
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5263<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5264<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5265 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5266</div>
5267
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5268<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5269
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5270<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5271<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5272 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5273</pre>
5274
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5275<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5276<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5277 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5278
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5279<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5280<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]5281 The second argument is a pointer to a <tt>va_list</tt> element to copy
5282 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5283
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5284<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5285<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]5286 macro available in C. In a target-dependent way, it copies the
5287 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5288 element. This intrinsic is necessary because
5289 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5290 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5291
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5292</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5293
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5294<!-- ======================================================================= -->
5295<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5296 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5297</div>
5298
5299<div class="doc_text">
5300
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5301<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5302Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5303intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5304roots on the stack</a>, as well as garbage collector implementations that
5305require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5306barriers. Front-ends for type-safe garbage collected languages should generate
5307these intrinsics to make use of the LLVM garbage collectors. For more details,
5308see <a href="GarbageCollection.html">Accurate Garbage Collection with
5309LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5310
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5311<p>The garbage collection intrinsics only operate on objects in the generic
5312 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5313
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5314</div>
5315
5316<!-- _______________________________________________________________________ -->
5317<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5318 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5319</div>
5320
5321<div class="doc_text">
5322
5323<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5324<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5325 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5326</pre>
5327
5328<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5329<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]5330 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5331
5332<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5333<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5334 root pointer. The second pointer (which must be either a constant or a
5335 global value address) contains the meta-data to be associated with the
5336 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5337
5338<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5339<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]5340 location. At compile-time, the code generator generates information to allow
5341 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5342 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5343 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5344
5345</div>
5346
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5347<!-- _______________________________________________________________________ -->
5348<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5349 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5350</div>
5351
5352<div class="doc_text">
5353
5354<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5355<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5356 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5357</pre>
5358
5359<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5360<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5361 locations, allowing garbage collector implementations that require read
5362 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5363
5364<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5365<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]5366 allocated from the garbage collector. The first object is a pointer to the
5367 start of the referenced object, if needed by the language runtime (otherwise
5368 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5369
5370<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5371<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5372 instruction, but may be replaced with substantially more complex code by the
5373 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5374 may only be used in a function which <a href="#gc">specifies a GC
5375 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5376
5377</div>
5378
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5379<!-- _______________________________________________________________________ -->
5380<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5381 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5382</div>
5383
5384<div class="doc_text">
5385
5386<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5387<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5388 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5389</pre>
5390
5391<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5392<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5393 locations, allowing garbage collector implementations that require write
5394 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5395
5396<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5397<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]5398 object to store it to, and the third is the address of the field of Obj to
5399 store to. If the runtime does not require a pointer to the object, Obj may
5400 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5401
5402<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5403<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5404 instruction, but may be replaced with substantially more complex code by the
5405 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5406 may only be used in a function which <a href="#gc">specifies a GC
5407 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5408
5409</div>
5410
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5411<!-- ======================================================================= -->
5412<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5413 <a name="int_codegen">Code Generator Intrinsics</a>
5414</div>
5415
5416<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5417
5418<p>These intrinsics are provided by LLVM to expose special features that may
5419 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5420
5421</div>
5422
5423<!-- _______________________________________________________________________ -->
5424<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5425 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5426</div>
5427
5428<div class="doc_text">
5429
5430<h5>Syntax:</h5>
5431<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5432 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5433</pre>
5434
5435<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5436<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5437 target-specific value indicating the return address of the current function
5438 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5439
5440<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5441<p>The argument to this intrinsic indicates which function to return the address
5442 for. Zero indicates the calling function, one indicates its caller, etc.
5443 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5444
5445<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5446<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5447 indicating the return address of the specified call frame, or zero if it
5448 cannot be identified. The value returned by this intrinsic is likely to be
5449 incorrect or 0 for arguments other than zero, so it should only be used for
5450 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5451
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5452<p>Note that calling this intrinsic does not prevent function inlining or other
5453 aggressive transformations, so the value returned may not be that of the
5454 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5455
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5456</div>
5457
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5458<!-- _______________________________________________________________________ -->
5459<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5460 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5461</div>
5462
5463<div class="doc_text">
5464
5465<h5>Syntax:</h5>
5466<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5467 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5468</pre>
5469
5470<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5471<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5472 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5473
5474<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5475<p>The argument to this intrinsic indicates which function to return the frame
5476 pointer for. Zero indicates the calling function, one indicates its caller,
5477 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5478
5479<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5480<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5481 indicating the frame address of the specified call frame, or zero if it
5482 cannot be identified. The value returned by this intrinsic is likely to be
5483 incorrect or 0 for arguments other than zero, so it should only be used for
5484 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5485
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5486<p>Note that calling this intrinsic does not prevent function inlining or other
5487 aggressive transformations, so the value returned may not be that of the
5488 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5489
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5490</div>
5491
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5492<!-- _______________________________________________________________________ -->
5493<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5494 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5495</div>
5496
5497<div class="doc_text">
5498
5499<h5>Syntax:</h5>
5500<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5501 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5502</pre>
5503
5504<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5505<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5506 of the function stack, for use
5507 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5508 useful for implementing language features like scoped automatic variable
5509 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5510
5511<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5512<p>This intrinsic returns a opaque pointer value that can be passed
5513 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5514 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5515 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5516 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5517 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5518 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5519
5520</div>
5521
5522<!-- _______________________________________________________________________ -->
5523<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5524 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5525</div>
5526
5527<div class="doc_text">
5528
5529<h5>Syntax:</h5>
5530<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5531 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5532</pre>
5533
5534<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5535<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5536 the function stack to the state it was in when the
5537 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5538 executed. This is useful for implementing language features like scoped
5539 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5540
5541<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5542<p>See the description
5543 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5544
5545</div>
5546
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5547<!-- _______________________________________________________________________ -->
5548<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5549 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5550</div>
5551
5552<div class="doc_text">
5553
5554<h5>Syntax:</h5>
5555<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5556 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]5557</pre>
5558
5559<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5560<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5561 insert a prefetch instruction if supported; otherwise, it is a noop.
5562 Prefetches have no effect on the behavior of the program but can change its
5563 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5564
5565<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5566<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5567 specifier determining if the fetch should be for a read (0) or write (1),
5568 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5569 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5570 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5571
5572<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5573<p>This intrinsic does not modify the behavior of the program. In particular,
5574 prefetches cannot trap and do not produce a value. On targets that support
5575 this intrinsic, the prefetch can provide hints to the processor cache for
5576 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5577
5578</div>
5579
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5580<!-- _______________________________________________________________________ -->
5581<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5582 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5583</div>
5584
5585<div class="doc_text">
5586
5587<h5>Syntax:</h5>
5588<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5589 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5590</pre>
5591
5592<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5593<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5594 Counter (PC) in a region of code to simulators and other tools. The method
5595 is target specific, but it is expected that the marker will use exported
5596 symbols to transmit the PC of the marker. The marker makes no guarantees
5597 that it will remain with any specific instruction after optimizations. It is
5598 possible that the presence of a marker will inhibit optimizations. The
5599 intended use is to be inserted after optimizations to allow correlations of
5600 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5601
5602<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5603<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5604
5605<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5606<p>This intrinsic does not modify the behavior of the program. Backends that do
5607 not support this intrinisic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5608
5609</div>
5610
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5611<!-- _______________________________________________________________________ -->
5612<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5613 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5614</div>
5615
5616<div class="doc_text">
5617
5618<h5>Syntax:</h5>
5619<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5620 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5621</pre>
5622
5623<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5624<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5625 counter register (or similar low latency, high accuracy clocks) on those
5626 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5627 should map to RPCC. As the backing counters overflow quickly (on the order
5628 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5629
5630<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5631<p>When directly supported, reading the cycle counter should not modify any
5632 memory. Implementations are allowed to either return a application specific
5633 value or a system wide value. On backends without support, this is lowered
5634 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5635
5636</div>
5637
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5638<!-- ======================================================================= -->
5639<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5640 <a name="int_libc">Standard C Library Intrinsics</a>
5641</div>
5642
5643<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5644
5645<p>LLVM provides intrinsics for a few important standard C library functions.
5646 These intrinsics allow source-language front-ends to pass information about
5647 the alignment of the pointer arguments to the code generator, providing
5648 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5649
5650</div>
5651
5652<!-- _______________________________________________________________________ -->
5653<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5654 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5655</div>
5656
5657<div class="doc_text">
5658
5659<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5660<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5661 integer bit width. Not all targets support all bit widths however.</p>
5662
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5663<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5664 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5665 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5666 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5667 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5668 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5669 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5670 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5671 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5672</pre>
5673
5674<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5675<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5676 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5677
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5678<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5679 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5680
5681<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5682<p>The first argument is a pointer to the destination, the second is a pointer
5683 to the source. The third argument is an integer argument specifying the
5684 number of bytes to copy, and the fourth argument is the alignment of the
5685 source and destination locations.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5686
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5687<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5688 then the caller guarantees that both the source and destination pointers are
5689 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5690
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5691<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5692<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5693 source location to the destination location, which are not allowed to
5694 overlap. It copies "len" bytes of memory over. If the argument is known to
5695 be aligned to some boundary, this can be specified as the fourth argument,
5696 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5697
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5698</div>
5699
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5700<!-- _______________________________________________________________________ -->
5701<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5702 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5703</div>
5704
5705<div class="doc_text">
5706
5707<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5708<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5709 width. Not all targets support all bit widths however.</p>
5710
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5711<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5712 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5713 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5714 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5715 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5716 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5717 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5718 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5719 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5720</pre>
5721
5722<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5723<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5724 source location to the destination location. It is similar to the
5725 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5726 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5727
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5728<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5729 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5730
5731<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5732<p>The first argument is a pointer to the destination, the second is a pointer
5733 to the source. The third argument is an integer argument specifying the
5734 number of bytes to copy, and the fourth argument is the alignment of the
5735 source and destination locations.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5736
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5737<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5738 then the caller guarantees that the source and destination pointers are
5739 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5740
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5741<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5742<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5743 source location to the destination location, which may overlap. It copies
5744 "len" bytes of memory over. If the argument is known to be aligned to some
5745 boundary, this can be specified as the fourth argument, otherwise it should
5746 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5747
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5748</div>
5749
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5750<!-- _______________________________________________________________________ -->
5751<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5752 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5753</div>
5754
5755<div class="doc_text">
5756
5757<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5758<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5759 width. Not all targets support all bit widths however.</p>
5760
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5761<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5762 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5763 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5764 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5765 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5766 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5767 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5768 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5769 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5770</pre>
5771
5772<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5773<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5774 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5775
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5776<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5777 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5778
5779<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5780<p>The first argument is a pointer to the destination to fill, the second is the
5781 byte value to fill it with, the third argument is an integer argument
5782 specifying the number of bytes to fill, and the fourth argument is the known
5783 alignment of destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5784
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5785<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5786 then the caller guarantees that the destination pointer is aligned to that
5787 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5788
5789<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5790<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5791 at the destination location. If the argument is known to be aligned to some
5792 boundary, this can be specified as the fourth argument, otherwise it should
5793 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5794
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5795</div>
5796
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5797<!-- _______________________________________________________________________ -->
5798<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5799 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5800</div>
5801
5802<div class="doc_text">
5803
5804<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5805<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5806 floating point or vector of floating point type. Not all targets support all
5807 types however.</p>
5808
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5809<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5810 declare float @llvm.sqrt.f32(float %Val)
5811 declare double @llvm.sqrt.f64(double %Val)
5812 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5813 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5814 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5815</pre>
5816
5817<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5818<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5819 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5820 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5821 behavior for negative numbers other than -0.0 (which allows for better
5822 optimization, because there is no need to worry about errno being
5823 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]5824
5825<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5826<p>The argument and return value are floating point numbers of the same
5827 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5828
5829<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5830<p>This function returns the sqrt of the specified operand if it is a
5831 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5832
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5833</div>
5834
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5835<!-- _______________________________________________________________________ -->
5836<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5837 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5838</div>
5839
5840<div class="doc_text">
5841
5842<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5843<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5844 floating point or vector of floating point type. Not all targets support all
5845 types however.</p>
5846
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5847<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5848 declare float @llvm.powi.f32(float %Val, i32 %power)
5849 declare double @llvm.powi.f64(double %Val, i32 %power)
5850 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5851 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5852 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5853</pre>
5854
5855<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5856<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5857 specified (positive or negative) power. The order of evaluation of
5858 multiplications is not defined. When a vector of floating point type is
5859 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5860
5861<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5862<p>The second argument is an integer power, and the first is a value to raise to
5863 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5864
5865<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5866<p>This function returns the first value raised to the second power with an
5867 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5868
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5869</div>
5870
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5871<!-- _______________________________________________________________________ -->
5872<div class="doc_subsubsection">
5873 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5874</div>
5875
5876<div class="doc_text">
5877
5878<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5879<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5880 floating point or vector of floating point type. Not all targets support all
5881 types however.</p>
5882
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5883<pre>
5884 declare float @llvm.sin.f32(float %Val)
5885 declare double @llvm.sin.f64(double %Val)
5886 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5887 declare fp128 @llvm.sin.f128(fp128 %Val)
5888 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5889</pre>
5890
5891<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5892<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5893
5894<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5895<p>The argument and return value are floating point numbers of the same
5896 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5897
5898<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5899<p>This function returns the sine of the specified operand, returning the same
5900 values as the libm <tt>sin</tt> functions would, and handles error conditions
5901 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5902
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5903</div>
5904
5905<!-- _______________________________________________________________________ -->
5906<div class="doc_subsubsection">
5907 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5908</div>
5909
5910<div class="doc_text">
5911
5912<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5913<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5914 floating point or vector of floating point type. Not all targets support all
5915 types however.</p>
5916
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5917<pre>
5918 declare float @llvm.cos.f32(float %Val)
5919 declare double @llvm.cos.f64(double %Val)
5920 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5921 declare fp128 @llvm.cos.f128(fp128 %Val)
5922 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5923</pre>
5924
5925<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5926<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5927
5928<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5929<p>The argument and return value are floating point numbers of the same
5930 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5931
5932<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5933<p>This function returns the cosine of the specified operand, returning the same
5934 values as the libm <tt>cos</tt> functions would, and handles error conditions
5935 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5936
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5937</div>
5938
5939<!-- _______________________________________________________________________ -->
5940<div class="doc_subsubsection">
5941 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5942</div>
5943
5944<div class="doc_text">
5945
5946<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5947<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5948 floating point or vector of floating point type. Not all targets support all
5949 types however.</p>
5950
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5951<pre>
5952 declare float @llvm.pow.f32(float %Val, float %Power)
5953 declare double @llvm.pow.f64(double %Val, double %Power)
5954 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5955 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5956 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5957</pre>
5958
5959<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5960<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5961 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5962
5963<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5964<p>The second argument is a floating point power, and the first is a value to
5965 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5966
5967<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5968<p>This function returns the first value raised to the second power, returning
5969 the same values as the libm <tt>pow</tt> functions would, and handles error
5970 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5971
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5972</div>
5973
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5974<!-- ======================================================================= -->
5975<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5976 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5977</div>
5978
5979<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5980
5981<p>LLVM provides intrinsics for a few important bit manipulation operations.
5982 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5983
5984</div>
5985
5986<!-- _______________________________________________________________________ -->
5987<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5988 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5989</div>
5990
5991<div class="doc_text">
5992
5993<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5994<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5995 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5996
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5997<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5998 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5999 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6000 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6001</pre>
6002
6003<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6004<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6005 values with an even number of bytes (positive multiple of 16 bits). These
6006 are useful for performing operations on data that is not in the target's
6007 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6008
6009<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6010<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6011 and low byte of the input i16 swapped. Similarly,
6012 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6013 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6014 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6015 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6016 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6017 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6018
6019</div>
6020
6021<!-- _______________________________________________________________________ -->
6022<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6023 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6024</div>
6025
6026<div class="doc_text">
6027
6028<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6029<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]6030 width. Not all targets support all bit widths however.</p>
6031
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6032<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6033 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6034 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6035 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6036 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6037 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6038</pre>
6039
6040<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6041<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6042 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6043
6044<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6045<p>The only argument is the value to be counted. The argument may be of any
6046 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6047
6048<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6049<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]6050
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6051</div>
6052
6053<!-- _______________________________________________________________________ -->
6054<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6055 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6056</div>
6057
6058<div class="doc_text">
6059
6060<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6061<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6062 integer bit width. Not all targets support all bit widths however.</p>
6063
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6064<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6065 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6066 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6067 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6068 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6069 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +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.ctlz</tt>' family of intrinsic functions counts the number of
6074 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6075
6076<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6077<p>The only argument is the value to be counted. The argument may be of any
6078 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6079
6080<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6081<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6082 zeros in a variable. If the src == 0 then the result is the size in bits of
6083 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6084
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6085</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6086
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6087<!-- _______________________________________________________________________ -->
6088<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6089 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6090</div>
6091
6092<div class="doc_text">
6093
6094<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6095<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6096 integer bit width. Not all targets support all bit widths however.</p>
6097
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6098<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6099 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6100 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6101 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6102 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6103 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6104</pre>
6105
6106<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6107<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6108 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6109
6110<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6111<p>The only argument is the value to be counted. The argument may be of any
6112 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6113
6114<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6115<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6116 zeros in a variable. If the src == 0 then the result is the size in bits of
6117 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6118
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6119</div>
6120
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6121<!-- ======================================================================= -->
6122<div class="doc_subsection">
6123 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6124</div>
6125
6126<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6127
6128<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6129
6130</div>
6131
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6132<!-- _______________________________________________________________________ -->
6133<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6134 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6135</div>
6136
6137<div class="doc_text">
6138
6139<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6140<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]6141 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6142
6143<pre>
6144 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6145 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6146 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6147</pre>
6148
6149<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6150<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6151 a signed addition of the two arguments, and indicate whether an overflow
6152 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6153
6154<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6155<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]6156 be of integer types of any bit width, but they must have the same bit
6157 width. The second element of the result structure must be of
6158 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6159 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6160
6161<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6162<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6163 a signed addition of the two variables. They return a structure &mdash; the
6164 first element of which is the signed summation, and the second element of
6165 which is a bit specifying if the signed summation resulted in an
6166 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6167
6168<h5>Examples:</h5>
6169<pre>
6170 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6171 %sum = extractvalue {i32, i1} %res, 0
6172 %obit = extractvalue {i32, i1} %res, 1
6173 br i1 %obit, label %overflow, label %normal
6174</pre>
6175
6176</div>
6177
6178<!-- _______________________________________________________________________ -->
6179<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6180 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6181</div>
6182
6183<div class="doc_text">
6184
6185<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6186<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]6187 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6188
6189<pre>
6190 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6191 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6192 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6193</pre>
6194
6195<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6196<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6197 an unsigned addition of the two arguments, and indicate whether a carry
6198 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6199
6200<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6201<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]6202 be of integer types of any bit width, but they must have the same bit
6203 width. The second element of the result structure must be of
6204 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6205 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6206
6207<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6208<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6209 an unsigned addition of the two arguments. They return a structure &mdash;
6210 the first element of which is the sum, and the second element of which is a
6211 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6212
6213<h5>Examples:</h5>
6214<pre>
6215 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6216 %sum = extractvalue {i32, i1} %res, 0
6217 %obit = extractvalue {i32, i1} %res, 1
6218 br i1 %obit, label %carry, label %normal
6219</pre>
6220
6221</div>
6222
6223<!-- _______________________________________________________________________ -->
6224<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6225 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6226</div>
6227
6228<div class="doc_text">
6229
6230<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6231<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]6232 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6233
6234<pre>
6235 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6236 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6237 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6238</pre>
6239
6240<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6241<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6242 a signed subtraction of the two arguments, and indicate whether an overflow
6243 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6244
6245<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6246<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]6247 be of integer types of any bit width, but they must have the same bit
6248 width. The second element of the result structure must be of
6249 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6250 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6251
6252<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6253<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6254 a signed subtraction of the two arguments. They return a structure &mdash;
6255 the first element of which is the subtraction, and the second element of
6256 which is a bit specifying if the signed subtraction resulted in an
6257 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6258
6259<h5>Examples:</h5>
6260<pre>
6261 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6262 %sum = extractvalue {i32, i1} %res, 0
6263 %obit = extractvalue {i32, i1} %res, 1
6264 br i1 %obit, label %overflow, label %normal
6265</pre>
6266
6267</div>
6268
6269<!-- _______________________________________________________________________ -->
6270<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6271 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6272</div>
6273
6274<div class="doc_text">
6275
6276<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6277<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]6278 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6279
6280<pre>
6281 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6282 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6283 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6284</pre>
6285
6286<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6287<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6288 an unsigned subtraction of the two arguments, and indicate whether an
6289 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6290
6291<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6292<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]6293 be of integer types of any bit width, but they must have the same bit
6294 width. The second element of the result structure must be of
6295 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6296 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6297
6298<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6299<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6300 an unsigned subtraction of the two arguments. They return a structure &mdash;
6301 the first element of which is the subtraction, and the second element of
6302 which is a bit specifying if the unsigned subtraction resulted in an
6303 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6304
6305<h5>Examples:</h5>
6306<pre>
6307 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6308 %sum = extractvalue {i32, i1} %res, 0
6309 %obit = extractvalue {i32, i1} %res, 1
6310 br i1 %obit, label %overflow, label %normal
6311</pre>
6312
6313</div>
6314
6315<!-- _______________________________________________________________________ -->
6316<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6317 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6318</div>
6319
6320<div class="doc_text">
6321
6322<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6323<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]6324 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6325
6326<pre>
6327 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6328 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6329 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6330</pre>
6331
6332<h5>Overview:</h5>
6333
6334<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6335 a signed multiplication of the two arguments, and indicate whether an
6336 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6337
6338<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6339<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]6340 be of integer types of any bit width, but they must have the same bit
6341 width. The second element of the result structure must be of
6342 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6343 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6344
6345<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6346<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6347 a signed multiplication of the two arguments. They return a structure &mdash;
6348 the first element of which is the multiplication, and the second element of
6349 which is a bit specifying if the signed multiplication resulted in an
6350 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6351
6352<h5>Examples:</h5>
6353<pre>
6354 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6355 %sum = extractvalue {i32, i1} %res, 0
6356 %obit = extractvalue {i32, i1} %res, 1
6357 br i1 %obit, label %overflow, label %normal
6358</pre>
6359
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6360</div>
6361
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6362<!-- _______________________________________________________________________ -->
6363<div class="doc_subsubsection">
6364 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6365</div>
6366
6367<div class="doc_text">
6368
6369<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6370<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]6371 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6372
6373<pre>
6374 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6375 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6376 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6377</pre>
6378
6379<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6380<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6381 a unsigned multiplication of the two arguments, and indicate whether an
6382 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6383
6384<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6385<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]6386 be of integer types of any bit width, but they must have the same bit
6387 width. The second element of the result structure must be of
6388 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6389 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6390
6391<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6392<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6393 an unsigned multiplication of the two arguments. They return a structure
6394 &mdash; the first element of which is the multiplication, and the second
6395 element of which is a bit specifying if the unsigned multiplication resulted
6396 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6397
6398<h5>Examples:</h5>
6399<pre>
6400 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6401 %sum = extractvalue {i32, i1} %res, 0
6402 %obit = extractvalue {i32, i1} %res, 1
6403 br i1 %obit, label %overflow, label %normal
6404</pre>
6405
6406</div>
6407
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6408<!-- ======================================================================= -->
6409<div class="doc_subsection">
6410 <a name="int_debugger">Debugger Intrinsics</a>
6411</div>
6412
6413<div class="doc_text">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6414
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6415<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6416 prefix), are described in
6417 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6418 Level Debugging</a> document.</p>
6419
6420</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6421
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6422<!-- ======================================================================= -->
6423<div class="doc_subsection">
6424 <a name="int_eh">Exception Handling Intrinsics</a>
6425</div>
6426
6427<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6428
6429<p>The LLVM exception handling intrinsics (which all start with
6430 <tt>llvm.eh.</tt> prefix), are described in
6431 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6432 Handling</a> document.</p>
6433
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6434</div>
6435
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6436<!-- ======================================================================= -->
6437<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6438 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6439</div>
6440
6441<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6442
6443<p>This intrinsic makes it possible to excise one parameter, marked with
6444 the <tt>nest</tt> attribute, from a function. The result is a callable
6445 function pointer lacking the nest parameter - the caller does not need to
6446 provide a value for it. Instead, the value to use is stored in advance in a
6447 "trampoline", a block of memory usually allocated on the stack, which also
6448 contains code to splice the nest value into the argument list. This is used
6449 to implement the GCC nested function address extension.</p>
6450
6451<p>For example, if the function is
6452 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6453 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6454 follows:</p>
6455
6456<div class="doc_code">
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6457<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6458 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6459 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6460 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6461 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6462</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6463</div>
6464
6465<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6466 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6467
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6468</div>
6469
6470<!-- _______________________________________________________________________ -->
6471<div class="doc_subsubsection">
6472 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6473</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6474
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6475<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6476
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6477<h5>Syntax:</h5>
6478<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6479 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]6480</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6481
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6482<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6483<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6484 function pointer suitable for executing it.</p>
6485
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6486<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6487<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6488 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6489 sufficiently aligned block of memory; this memory is written to by the
6490 intrinsic. Note that the size and the alignment are target-specific - LLVM
6491 currently provides no portable way of determining them, so a front-end that
6492 generates this intrinsic needs to have some target-specific knowledge.
6493 The <tt>func</tt> argument must hold a function bitcast to
6494 an <tt>i8*</tt>.</p>
6495
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6496<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6497<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6498 dependent code, turning it into a function. A pointer to this function is
6499 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6500 function pointer type</a> before being called. The new function's signature
6501 is the same as that of <tt>func</tt> with any arguments marked with
6502 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6503 is allowed, and it must be of pointer type. Calling the new function is
6504 equivalent to calling <tt>func</tt> with the same argument list, but
6505 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6506 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6507 by <tt>tramp</tt> is modified, then the effect of any later call to the
6508 returned function pointer is undefined.</p>
6509
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6510</div>
6511
6512<!-- ======================================================================= -->
6513<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6514 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6515</div>
6516
6517<div class="doc_text">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6518
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6519<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6520 hardware constructs for atomic operations and memory synchronization. This
6521 provides an interface to the hardware, not an interface to the programmer. It
6522 is aimed at a low enough level to allow any programming models or APIs
6523 (Application Programming Interfaces) which need atomic behaviors to map
6524 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6525 hardware provides a "universal IR" for source languages, it also provides a
6526 starting point for developing a "universal" atomic operation and
6527 synchronization IR.</p>
6528
6529<p>These do <em>not</em> form an API such as high-level threading libraries,
6530 software transaction memory systems, atomic primitives, and intrinsic
6531 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6532 application libraries. The hardware interface provided by LLVM should allow
6533 a clean implementation of all of these APIs and parallel programming models.
6534 No one model or paradigm should be selected above others unless the hardware
6535 itself ubiquitously does so.</p>
6536
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6537</div>
6538
6539<!-- _______________________________________________________________________ -->
6540<div class="doc_subsubsection">
6541 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6542</div>
6543<div class="doc_text">
6544<h5>Syntax:</h5>
6545<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6546 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]6547</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6548
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6549<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6550<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6551 specific pairs of memory access types.</p>
6552
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6553<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6554<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6555 The first four arguments enables a specific barrier as listed below. The
6556 fith argument specifies that the barrier applies to io or device or uncached
6557 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6558
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6559<ul>
6560 <li><tt>ll</tt>: load-load barrier</li>
6561 <li><tt>ls</tt>: load-store barrier</li>
6562 <li><tt>sl</tt>: store-load barrier</li>
6563 <li><tt>ss</tt>: store-store barrier</li>
6564 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6565</ul>
6566
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6567<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6568<p>This intrinsic causes the system to enforce some ordering constraints upon
6569 the loads and stores of the program. This barrier does not
6570 indicate <em>when</em> any events will occur, it only enforces
6571 an <em>order</em> in which they occur. For any of the specified pairs of load
6572 and store operations (f.ex. load-load, or store-load), all of the first
6573 operations preceding the barrier will complete before any of the second
6574 operations succeeding the barrier begin. Specifically the semantics for each
6575 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6576
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6577<ul>
6578 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6579 after the barrier begins.</li>
6580 <li><tt>ls</tt>: All loads before the barrier must complete before any
6581 store after the barrier begins.</li>
6582 <li><tt>ss</tt>: All stores before the barrier must complete before any
6583 store after the barrier begins.</li>
6584 <li><tt>sl</tt>: All stores before the barrier must complete before any
6585 load after the barrier begins.</li>
6586</ul>
6587
6588<p>These semantics are applied with a logical "and" behavior when more than one
6589 is enabled in a single memory barrier intrinsic.</p>
6590
6591<p>Backends may implement stronger barriers than those requested when they do
6592 not support as fine grained a barrier as requested. Some architectures do
6593 not need all types of barriers and on such architectures, these become
6594 noops.</p>
6595
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6596<h5>Example:</h5>
6597<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6598%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6599%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6600 store i32 4, %ptr
6601
6602%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6603 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6604 <i>; guarantee the above finishes</i>
6605 store i32 8, %ptr <i>; before this begins</i>
6606</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6607
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6608</div>
6609
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6610<!-- _______________________________________________________________________ -->
6611<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6612 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6613</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6614
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6615<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6616
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6617<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6618<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6619 any integer bit width and for different address spaces. Not all targets
6620 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6621
6622<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6623 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6624 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6625 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6626 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]6627</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6628
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6629<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6630<p>This loads a value in memory and compares it to a given value. If they are
6631 equal, it stores a new value into the memory.</p>
6632
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6633<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6634<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6635 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6636 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6637 this integer type. While any bit width integer may be used, targets may only
6638 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6639
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6640<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6641<p>This entire intrinsic must be executed atomically. It first loads the value
6642 in memory pointed to by <tt>ptr</tt> and compares it with the
6643 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6644 memory. The loaded value is yielded in all cases. This provides the
6645 equivalent of an atomic compare-and-swap operation within the SSA
6646 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6647
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6648<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6649<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6650%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6651%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6652 store i32 4, %ptr
6653
6654%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6655%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6656 <i>; yields {i32}:result1 = 4</i>
6657%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6658%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6659
6660%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6661%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6662 <i>; yields {i32}:result2 = 8</i>
6663%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6664
6665%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6666</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6667
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6668</div>
6669
6670<!-- _______________________________________________________________________ -->
6671<div class="doc_subsubsection">
6672 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6673</div>
6674<div class="doc_text">
6675<h5>Syntax:</h5>
6676
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6677<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6678 integer bit width. Not all targets support all bit widths however.</p>
6679
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6680<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6681 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6682 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6683 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6684 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]6685</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6686
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6687<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6688<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6689 the value from memory. It then stores the value in <tt>val</tt> in the memory
6690 at <tt>ptr</tt>.</p>
6691
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6692<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6693<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6694 the <tt>val</tt> argument and the result must be integers of the same bit
6695 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6696 integer type. The targets may only lower integer representations they
6697 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6698
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6699<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6700<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6701 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6702 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6703
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6704<h5>Examples:</h5>
6705<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6706%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6707%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6708 store i32 4, %ptr
6709
6710%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6711%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6712 <i>; yields {i32}:result1 = 4</i>
6713%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6714%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6715
6716%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6717%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6718 <i>; yields {i32}:result2 = 8</i>
6719
6720%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6721%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6722</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6723
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6724</div>
6725
6726<!-- _______________________________________________________________________ -->
6727<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6728 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6729
6730</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6731
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6732<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6733
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6734<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6735<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6736 any integer bit width. Not all targets support all bit widths however.</p>
6737
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6738<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6739 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6740 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6741 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6742 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]6743</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6744
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6745<h5>Overview:</h5>
6746<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6747 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6748
6749<h5>Arguments:</h5>
6750<p>The intrinsic takes two arguments, the first a pointer to an integer value
6751 and the second an integer value. The result is also an integer value. These
6752 integer types can have any bit width, but they must all have the same bit
6753 width. The targets may only lower integer representations they support.</p>
6754
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6755<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6756<p>This intrinsic does a series of operations atomically. It first loads the
6757 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6758 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]6759
6760<h5>Examples:</h5>
6761<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6762%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6763%ptr = bitcast i8* %mallocP to i32*
6764 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6765%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6766 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6767%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6768 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6769%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6770 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6771%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6772</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6773
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6774</div>
6775
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6776<!-- _______________________________________________________________________ -->
6777<div class="doc_subsubsection">
6778 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6779
6780</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6781
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6782<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6783
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6784<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6785<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6786 any integer bit width and for different address spaces. Not all targets
6787 support all bit widths however.</p>
6788
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6789<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6790 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6791 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6792 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6793 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]6794</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6795
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6796<h5>Overview:</h5>
6797<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6798 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6799
6800<h5>Arguments:</h5>
6801<p>The intrinsic takes two arguments, the first a pointer to an integer value
6802 and the second an integer value. The result is also an integer value. These
6803 integer types can have any bit width, but they must all have the same bit
6804 width. The targets may only lower integer representations they support.</p>
6805
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6806<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6807<p>This intrinsic does a series of operations atomically. It first loads the
6808 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6809 result to <tt>ptr</tt>. It yields the original value stored
6810 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6811
6812<h5>Examples:</h5>
6813<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6814%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6815%ptr = bitcast i8* %mallocP to i32*
6816 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6817%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6818 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6819%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6820 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6821%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6822 <i>; yields {i32}:result3 = 2</i>
6823%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6824</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6825
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6826</div>
6827
6828<!-- _______________________________________________________________________ -->
6829<div class="doc_subsubsection">
6830 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6831 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6832 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6833 <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]6834</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6835
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6836<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6837
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6838<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6839<p>These are overloaded intrinsics. You can
6840 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6841 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6842 bit width and for different address spaces. Not all targets support all bit
6843 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6844
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6845<pre>
6846 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6847 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6848 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6849 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]6850</pre>
6851
6852<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6853 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6854 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6855 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6856 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]6857</pre>
6858
6859<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6860 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6861 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6862 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6863 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]6864</pre>
6865
6866<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6867 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6868 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6869 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6870 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]6871</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6872
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6873<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6874<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6875 the value stored in memory at <tt>ptr</tt>. It yields the original value
6876 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6877
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6878<h5>Arguments:</h5>
6879<p>These intrinsics take two arguments, the first a pointer to an integer value
6880 and the second an integer value. The result is also an integer value. These
6881 integer types can have any bit width, but they must all have the same bit
6882 width. The targets may only lower integer representations they support.</p>
6883
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6884<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6885<p>These intrinsics does a series of operations atomically. They first load the
6886 value stored at <tt>ptr</tt>. They then do the bitwise
6887 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6888 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6889
6890<h5>Examples:</h5>
6891<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6892%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6893%ptr = bitcast i8* %mallocP to i32*
6894 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6895%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6896 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6897%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6898 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6899%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6900 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6901%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6902 <i>; yields {i32}:result3 = FF</i>
6903%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6904</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6905
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6906</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6907
6908<!-- _______________________________________________________________________ -->
6909<div class="doc_subsubsection">
6910 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6911 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6912 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6913 <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]6914</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6915
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6916<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6917
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6918<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6919<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6920 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6921 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6922 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6923
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6924<pre>
6925 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6926 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6927 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6928 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]6929</pre>
6930
6931<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6932 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6933 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6934 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6935 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]6936</pre>
6937
6938<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6939 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6940 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6941 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6942 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]6943</pre>
6944
6945<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6946 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6947 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6948 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6949 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]6950</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6951
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6952<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6953<p>These intrinsics takes the signed or unsigned minimum or maximum of
6954 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6955 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6956
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6957<h5>Arguments:</h5>
6958<p>These intrinsics take two arguments, the first a pointer to an integer value
6959 and the second an integer value. The result is also an integer value. These
6960 integer types can have any bit width, but they must all have the same bit
6961 width. The targets may only lower integer representations they support.</p>
6962
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6963<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6964<p>These intrinsics does a series of operations atomically. They first load the
6965 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6966 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6967 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6968
6969<h5>Examples:</h5>
6970<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6971%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6972%ptr = bitcast i8* %mallocP to i32*
6973 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6974%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6975 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6976%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6977 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6978%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6979 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6980%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6981 <i>; yields {i32}:result3 = 8</i>
6982%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6983</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6984
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6985</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6986
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]6987
6988<!-- ======================================================================= -->
6989<div class="doc_subsection">
6990 <a name="int_memorymarkers">Memory Use Markers</a>
6991</div>
6992
6993<div class="doc_text">
6994
6995<p>This class of intrinsics exists to information about the lifetime of memory
6996 objects and ranges where variables are immutable.</p>
6997
6998</div>
6999
7000<!-- _______________________________________________________________________ -->
7001<div class="doc_subsubsection">
7002 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7003</div>
7004
7005<div class="doc_text">
7006
7007<h5>Syntax:</h5>
7008<pre>
7009 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7010</pre>
7011
7012<h5>Overview:</h5>
7013<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7014 object's lifetime.</p>
7015
7016<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7017<p>The first argument is a constant integer representing the size of the
7018 object, or -1 if it is variable sized. The second argument is a pointer to
7019 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7020
7021<h5>Semantics:</h5>
7022<p>This intrinsic indicates that before this point in the code, the value of the
7023 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]7024 never be used and has an undefined value. A load from the pointer that
7025 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7026 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7027
7028</div>
7029
7030<!-- _______________________________________________________________________ -->
7031<div class="doc_subsubsection">
7032 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7033</div>
7034
7035<div class="doc_text">
7036
7037<h5>Syntax:</h5>
7038<pre>
7039 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7040</pre>
7041
7042<h5>Overview:</h5>
7043<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7044 object's lifetime.</p>
7045
7046<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7047<p>The first argument is a constant integer representing the size of the
7048 object, or -1 if it is variable sized. The second argument is a pointer to
7049 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7050
7051<h5>Semantics:</h5>
7052<p>This intrinsic indicates that after this point in the code, the value of the
7053 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7054 never be used and has an undefined value. Any stores into the memory object
7055 following this intrinsic may be removed as dead.
7056
7057</div>
7058
7059<!-- _______________________________________________________________________ -->
7060<div class="doc_subsubsection">
7061 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7062</div>
7063
7064<div class="doc_text">
7065
7066<h5>Syntax:</h5>
7067<pre>
7068 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7069</pre>
7070
7071<h5>Overview:</h5>
7072<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7073 a memory object will not change.</p>
7074
7075<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7076<p>The first argument is a constant integer representing the size of the
7077 object, or -1 if it is variable sized. The second argument is a pointer to
7078 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7079
7080<h5>Semantics:</h5>
7081<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7082 the return value, the referenced memory location is constant and
7083 unchanging.</p>
7084
7085</div>
7086
7087<!-- _______________________________________________________________________ -->
7088<div class="doc_subsubsection">
7089 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7090</div>
7091
7092<div class="doc_text">
7093
7094<h5>Syntax:</h5>
7095<pre>
7096 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7097</pre>
7098
7099<h5>Overview:</h5>
7100<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7101 a memory object are mutable.</p>
7102
7103<h5>Arguments:</h5>
7104<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7105 The second argument is a constant integer representing the size of the
7106 object, or -1 if it is variable sized and the third argument is a pointer
7107 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7108
7109<h5>Semantics:</h5>
7110<p>This intrinsic indicates that the memory is mutable again.</p>
7111
7112</div>
7113
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7114<!-- ======================================================================= -->
7115<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7116 <a name="int_general">General Intrinsics</a>
7117</div>
7118
7119<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7120
7121<p>This class of intrinsics is designed to be generic and has no specific
7122 purpose.</p>
7123
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7124</div>
7125
7126<!-- _______________________________________________________________________ -->
7127<div class="doc_subsubsection">
7128 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7129</div>
7130
7131<div class="doc_text">
7132
7133<h5>Syntax:</h5>
7134<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]7135 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]7136</pre>
7137
7138<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7139<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7140
7141<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7142<p>The first argument is a pointer to a value, the second is a pointer to a
7143 global string, the third is a pointer to a global string which is the source
7144 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7145
7146<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7147<p>This intrinsic allows annotation of local variables with arbitrary strings.
7148 This can be useful for special purpose optimizations that want to look for
7149 these annotations. These have no other defined use, they are ignored by code
7150 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7151
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7152</div>
7153
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7154<!-- _______________________________________________________________________ -->
7155<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7156 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7157</div>
7158
7159<div class="doc_text">
7160
7161<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7162<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7163 any integer bit width.</p>
7164
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7165<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]7166 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7167 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7168 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7169 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7170 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]7171</pre>
7172
7173<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7174<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7175
7176<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7177<p>The first argument is an integer value (result of some expression), the
7178 second is a pointer to a global string, the third is a pointer to a global
7179 string which is the source file name, and the last argument is the line
7180 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7181
7182<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7183<p>This intrinsic allows annotations to be put on arbitrary expressions with
7184 arbitrary strings. This can be useful for special purpose optimizations that
7185 want to look for these annotations. These have no other defined use, they
7186 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7187
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7188</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7189
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7190<!-- _______________________________________________________________________ -->
7191<div class="doc_subsubsection">
7192 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7193</div>
7194
7195<div class="doc_text">
7196
7197<h5>Syntax:</h5>
7198<pre>
7199 declare void @llvm.trap()
7200</pre>
7201
7202<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7203<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7204
7205<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7206<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7207
7208<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7209<p>This intrinsics is lowered to the target dependent trap instruction. If the
7210 target does not have a trap instruction, this intrinsic will be lowered to
7211 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7212
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7213</div>
7214
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7215<!-- _______________________________________________________________________ -->
7216<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7217 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7218</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7219
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7220<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7221
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7222<h5>Syntax:</h5>
7223<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7224 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7225</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7226
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7227<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7228<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7229 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7230 ensure that it is placed on the stack before local variables.</p>
7231
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7232<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7233<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7234 arguments. The first argument is the value loaded from the stack
7235 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7236 that has enough space to hold the value of the guard.</p>
7237
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7238<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7239<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7240 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7241 stack. This is to ensure that if a local variable on the stack is
7242 overwritten, it will destroy the value of the guard. When the function exits,
7243 the guard on the stack is checked against the original guard. If they're
7244 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7245 function.</p>
7246
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7247</div>
7248
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7249<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7250<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7251<address>
7252 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7253 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7254 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7255 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]7256
7257 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]7258 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7259 Last modified: $Date$
7260</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]7261
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]7262</body>
7263</html>