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gerrit-public.fairphone.software / toolchain / llvm-project / c2f8f16162469096a32332d829f7971409c91210 / . / llvm / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner80d73c72009-10-10 18:26:06 +0000[diff] [blame]34 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]46 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]47 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]48 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]49 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]50 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]51 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]52 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]53 </ol>
54 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]55 <li><a href="#typesystem">Type System</a>
56 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]57 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]58 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]59 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]60 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_floating">Floating Point Types</a></li>
62 <li><a href="#t_void">Void Type</a></li>
63 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]64 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]65 </ol>
66 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#t_derived">Derived Types</a>
68 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]69 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]70 <li><a href="#t_function">Function Type</a></li>
71 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]72 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]73 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]74 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]75 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]76 </ol>
77 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]78 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]79 </ol>
80 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]81 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]82 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]83 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]84 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]85 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
86 <li><a href="#undefvalues">Undefined Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]87 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]88 <li><a href="#constantexprs">Constant Expressions</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>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]94 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]95 </ol>
96 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]97 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
98 <ol>
99 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]100 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
101 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]102 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
103 Global Variable</a></li>
104 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
105 Global Variable</a></li>
106 </ol>
107 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]108 <li><a href="#instref">Instruction Reference</a>
109 <ol>
110 <li><a href="#terminators">Terminator Instructions</a>
111 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]112 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
113 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]114 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]115 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]116 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]117 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]118 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]119 </ol>
120 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]121 <li><a href="#binaryops">Binary Operations</a>
122 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]123 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]124 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]126 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]127 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]128 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]129 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
130 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
131 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]132 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
133 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
134 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]135 </ol>
136 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]137 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
138 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]139 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
140 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
141 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]142 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]143 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]144 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]145 </ol>
146 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]147 <li><a href="#vectorops">Vector Operations</a>
148 <ol>
149 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
150 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
151 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]152 </ol>
153 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]154 <li><a href="#aggregateops">Aggregate Operations</a>
155 <ol>
156 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
157 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
158 </ol>
159 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]160 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]161 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]162 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]163 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
164 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
165 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]166 </ol>
167 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]168 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]169 <ol>
170 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
171 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
174 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]175 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
176 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
177 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
178 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]179 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
180 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]181 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]182 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]183 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]184 <li><a href="#otherops">Other Operations</a>
185 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]186 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
187 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]188 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]189 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]190 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]191 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]192 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]193 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]194 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]195 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]196 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]197 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]198 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
199 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]200 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
202 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]203 </ol>
204 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]205 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
206 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]207 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
209 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]210 </ol>
211 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]212 <li><a href="#int_codegen">Code Generator Intrinsics</a>
213 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]214 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
216 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
217 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
218 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
219 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
220 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]221 </ol>
222 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]223 <li><a href="#int_libc">Standard C Library Intrinsics</a>
224 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]225 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
229 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]230 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
232 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]233 </ol>
234 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]235 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]236 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]237 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]238 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
240 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]241 </ol>
242 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]243 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
244 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]245 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
248 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
249 <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]250 <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]251 </ol>
252 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]253 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]254 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]255 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]256 <ol>
257 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]258 </ol>
259 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]260 <li><a href="#int_atomics">Atomic intrinsics</a>
261 <ol>
262 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
263 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
264 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
265 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
266 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
267 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
268 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
269 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
270 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
271 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
272 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
273 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
274 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
275 </ol>
276 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]277 <li><a href="#int_memorymarkers">Memory Use Markers</a>
278 <ol>
279 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
280 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
281 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
282 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
283 </ol>
284 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]285 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]286 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]287 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]288 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]289 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]290 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]291 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]292 '<tt>llvm.trap</tt>' Intrinsic</a></li>
293 <li><a href="#int_stackprotector">
294 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]295 <li><a href="#int_objectsize">
296 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]297 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]298 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]299 </ol>
300 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]301</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]302
303<div class="doc_author">
304 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
305 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]306</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]307
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]308<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]309<div class="doc_section"> <a name="abstract">Abstract </a></div>
310<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]311
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]312<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]313
314<p>This document is a reference manual for the LLVM assembly language. LLVM is
315 a Static Single Assignment (SSA) based representation that provides type
316 safety, low-level operations, flexibility, and the capability of representing
317 'all' high-level languages cleanly. It is the common code representation
318 used throughout all phases of the LLVM compilation strategy.</p>
319
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]320</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]322<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]323<div class="doc_section"> <a name="introduction">Introduction</a> </div>
324<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]325
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]326<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]327
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]328<p>The LLVM code representation is designed to be used in three different forms:
329 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
330 for fast loading by a Just-In-Time compiler), and as a human readable
331 assembly language representation. This allows LLVM to provide a powerful
332 intermediate representation for efficient compiler transformations and
333 analysis, while providing a natural means to debug and visualize the
334 transformations. The three different forms of LLVM are all equivalent. This
335 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]336
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]337<p>The LLVM representation aims to be light-weight and low-level while being
338 expressive, typed, and extensible at the same time. It aims to be a
339 "universal IR" of sorts, by being at a low enough level that high-level ideas
340 may be cleanly mapped to it (similar to how microprocessors are "universal
341 IR's", allowing many source languages to be mapped to them). By providing
342 type information, LLVM can be used as the target of optimizations: for
343 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]344 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]345 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]346
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]347</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]348
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]349<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]350<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]351
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]352<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]354<p>It is important to note that this document describes 'well formed' LLVM
355 assembly language. There is a difference between what the parser accepts and
356 what is considered 'well formed'. For example, the following instruction is
357 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]358
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]359<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]360<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]361%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]362</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]363</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]364
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]365<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
366 LLVM infrastructure provides a verification pass that may be used to verify
367 that an LLVM module is well formed. This pass is automatically run by the
368 parser after parsing input assembly and by the optimizer before it outputs
369 bitcode. The violations pointed out by the verifier pass indicate bugs in
370 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]371
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]372</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]373
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]374<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]376<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]377<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]378<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]379
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]380<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]381
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]382<p>LLVM identifiers come in two basic types: global and local. Global
383 identifiers (functions, global variables) begin with the <tt>'@'</tt>
384 character. Local identifiers (register names, types) begin with
385 the <tt>'%'</tt> character. Additionally, there are three different formats
386 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]387
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]388<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]389 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]390 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
391 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
392 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
393 other characters in their names can be surrounded with quotes. Special
394 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
395 ASCII code for the character in hexadecimal. In this way, any character
396 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]397
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]398 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]399 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]400
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]401 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]402 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]403</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]404
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]405<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]406 don't need to worry about name clashes with reserved words, and the set of
407 reserved words may be expanded in the future without penalty. Additionally,
408 unnamed identifiers allow a compiler to quickly come up with a temporary
409 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]410
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]411<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]412 languages. There are keywords for different opcodes
413 ('<tt><a href="#i_add">add</a></tt>',
414 '<tt><a href="#i_bitcast">bitcast</a></tt>',
415 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
416 ('<tt><a href="#t_void">void</a></tt>',
417 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
418 reserved words cannot conflict with variable names, because none of them
419 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]420
421<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]422 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]423
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]424<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]425
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]426<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]427<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]428%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]429</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]430</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]431
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]432<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]433
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]434<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]435<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]436%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]437</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]438</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]439
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]440<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]441
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]442<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]443<pre>
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]444%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
445%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]446%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]447</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]448</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]449
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]450<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
451 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]452
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]453<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]454 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]455 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456
457 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]458 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]460 <li>Unnamed temporaries are numbered sequentially</li>
461</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]462
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]463<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]464 demonstrating instructions, we will follow an instruction with a comment that
465 defines the type and name of value produced. Comments are shown in italic
466 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]468</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]469
470<!-- *********************************************************************** -->
471<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
472<!-- *********************************************************************** -->
473
474<!-- ======================================================================= -->
475<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
476</div>
477
478<div class="doc_text">
479
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]480<p>LLVM programs are composed of "Module"s, each of which is a translation unit
481 of the input programs. Each module consists of functions, global variables,
482 and symbol table entries. Modules may be combined together with the LLVM
483 linker, which merges function (and global variable) definitions, resolves
484 forward declarations, and merges symbol table entries. Here is an example of
485 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]486
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]487<div class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]488<pre>
489<i>; Declare the string constant as a global constant.</i>
490<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]491
492<i>; External declaration of the puts function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]493<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]494
495<i>; Definition of main function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]496define i32 @main() { <i>; i32()* </i>
497 <i>; Convert [13 x i8]* to i8 *...</i>
498 %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]499
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]500 <i>; Call puts function to write out the string to stdout.</i>
501 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]502 <a href="#i_ret">ret</a> i32 0<br>}
503
504<i>; Named metadata</i>
505!1 = metadata !{i32 41}
506!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]507</pre>
508</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]509
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]510<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]511 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]512 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]513 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
514 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]515
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]516<p>In general, a module is made up of a list of global values, where both
517 functions and global variables are global values. Global values are
518 represented by a pointer to a memory location (in this case, a pointer to an
519 array of char, and a pointer to a function), and have one of the
520 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]521
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]522</div>
523
524<!-- ======================================================================= -->
525<div class="doc_subsection">
526 <a name="linkage">Linkage Types</a>
527</div>
528
529<div class="doc_text">
530
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]531<p>All Global Variables and Functions have one of the following types of
532 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]533
534<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]535 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]536 <dd>Global values with private linkage are only directly accessible by objects
537 in the current module. In particular, linking code into a module with an
538 private global value may cause the private to be renamed as necessary to
539 avoid collisions. Because the symbol is private to the module, all
540 references can be updated. This doesn't show up in any symbol table in the
541 object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]542
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]543 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]544 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere7f064e2009-08-24 04:32:16 +0000[diff] [blame]545 removed by the linker after evaluation. Note that (unlike private
546 symbols) linker_private symbols are subject to coalescing by the linker:
547 weak symbols get merged and redefinitions are rejected. However, unlike
548 normal strong symbols, they are removed by the linker from the final
549 linked image (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]550
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]551 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]552 <dd>Similar to private, but the value shows as a local symbol
553 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
554 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]555
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]556 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]557 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]558 into the object file corresponding to the LLVM module. They exist to
559 allow inlining and other optimizations to take place given knowledge of
560 the definition of the global, which is known to be somewhere outside the
561 module. Globals with <tt>available_externally</tt> linkage are allowed to
562 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
563 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]564
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]565 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]566 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]567 the same name when linkage occurs. This can be used to implement
568 some forms of inline functions, templates, or other code which must be
569 generated in each translation unit that uses it, but where the body may
570 be overridden with a more definitive definition later. Unreferenced
571 <tt>linkonce</tt> globals are allowed to be discarded. Note that
572 <tt>linkonce</tt> linkage does not actually allow the optimizer to
573 inline the body of this function into callers because it doesn't know if
574 this definition of the function is the definitive definition within the
575 program or whether it will be overridden by a stronger definition.
576 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
577 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]578
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]579 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]580 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
581 <tt>linkonce</tt> linkage, except that unreferenced globals with
582 <tt>weak</tt> linkage may not be discarded. This is used for globals that
583 are declared "weak" in C source code.</dd>
584
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]585 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]586 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
587 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
588 global scope.
589 Symbols with "<tt>common</tt>" linkage are merged in the same way as
590 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]591 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]592 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]593 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
594 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]595
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]596
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]597 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]598 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]599 pointer to array type. When two global variables with appending linkage
600 are linked together, the two global arrays are appended together. This is
601 the LLVM, typesafe, equivalent of having the system linker append together
602 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]603
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]604 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]605 <dd>The semantics of this linkage follow the ELF object file model: the symbol
606 is weak until linked, if not linked, the symbol becomes null instead of
607 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]608
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
610 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]611 <dd>Some languages allow differing globals to be merged, such as two functions
612 with different semantics. Other languages, such as <tt>C++</tt>, ensure
613 that only equivalent globals are ever merged (the "one definition rule" -
614 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
615 and <tt>weak_odr</tt> linkage types to indicate that the global will only
616 be merged with equivalent globals. These linkage types are otherwise the
617 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]618
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]619 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]620 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]621 visible, meaning that it participates in linkage and can be used to
622 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]623</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]624
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]625<p>The next two types of linkage are targeted for Microsoft Windows platform
626 only. They are designed to support importing (exporting) symbols from (to)
627 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]628
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]629<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]630 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]631 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]632 or variable via a global pointer to a pointer that is set up by the DLL
633 exporting the symbol. On Microsoft Windows targets, the pointer name is
634 formed by combining <code>__imp_</code> and the function or variable
635 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]636
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]637 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]638 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]639 pointer to a pointer in a DLL, so that it can be referenced with the
640 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
641 name is formed by combining <code>__imp_</code> and the function or
642 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]643</dl>
644
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]645<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
646 another module defined a "<tt>.LC0</tt>" variable and was linked with this
647 one, one of the two would be renamed, preventing a collision. Since
648 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
649 declarations), they are accessible outside of the current module.</p>
650
651<p>It is illegal for a function <i>declaration</i> to have any linkage type
652 other than "externally visible", <tt>dllimport</tt>
653 or <tt>extern_weak</tt>.</p>
654
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]655<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]656 or <tt>weak_odr</tt> linkages.</p>
657
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]658</div>
659
660<!-- ======================================================================= -->
661<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]662 <a name="callingconv">Calling Conventions</a>
663</div>
664
665<div class="doc_text">
666
667<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]668 and <a href="#i_invoke">invokes</a> can all have an optional calling
669 convention specified for the call. The calling convention of any pair of
670 dynamic caller/callee must match, or the behavior of the program is
671 undefined. The following calling conventions are supported by LLVM, and more
672 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]673
674<dl>
675 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]676 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]677 specified) matches the target C calling conventions. This calling
678 convention supports varargs function calls and tolerates some mismatch in
679 the declared prototype and implemented declaration of the function (as
680 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]681
682 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]683 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]684 (e.g. by passing things in registers). This calling convention allows the
685 target to use whatever tricks it wants to produce fast code for the
686 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]687 (Application Binary Interface).
688 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
689 when this convention is used.</a> This calling convention does not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]690 support varargs and requires the prototype of all callees to exactly match
691 the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]692
693 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]694 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]695 as possible under the assumption that the call is not commonly executed.
696 As such, these calls often preserve all registers so that the call does
697 not break any live ranges in the caller side. This calling convention
698 does not support varargs and requires the prototype of all callees to
699 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]700
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]701 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]702 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]703 target-specific calling conventions to be used. Target specific calling
704 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]705</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]706
707<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]708 support Pascal conventions or any other well-known target-independent
709 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]710
711</div>
712
713<!-- ======================================================================= -->
714<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]715 <a name="visibility">Visibility Styles</a>
716</div>
717
718<div class="doc_text">
719
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]720<p>All Global Variables and Functions have one of the following visibility
721 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]722
723<dl>
724 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]725 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]726 that the declaration is visible to other modules and, in shared libraries,
727 means that the declared entity may be overridden. On Darwin, default
728 visibility means that the declaration is visible to other modules. Default
729 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]730
731 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]732 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]733 object if they are in the same shared object. Usually, hidden visibility
734 indicates that the symbol will not be placed into the dynamic symbol
735 table, so no other module (executable or shared library) can reference it
736 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]737
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]738 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]739 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]740 the dynamic symbol table, but that references within the defining module
741 will bind to the local symbol. That is, the symbol cannot be overridden by
742 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]743</dl>
744
745</div>
746
747<!-- ======================================================================= -->
748<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]749 <a name="namedtypes">Named Types</a>
750</div>
751
752<div class="doc_text">
753
754<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]755 it easier to read the IR and make the IR more condensed (particularly when
756 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]757
758<div class="doc_code">
759<pre>
760%mytype = type { %mytype*, i32 }
761</pre>
762</div>
763
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]764<p>You may give a name to any <a href="#typesystem">type</a> except
765 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
766 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]767
768<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]769 and that you can therefore specify multiple names for the same type. This
770 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
771 uses structural typing, the name is not part of the type. When printing out
772 LLVM IR, the printer will pick <em>one name</em> to render all types of a
773 particular shape. This means that if you have code where two different
774 source types end up having the same LLVM type, that the dumper will sometimes
775 print the "wrong" or unexpected type. This is an important design point and
776 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]777
778</div>
779
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]780<!-- ======================================================================= -->
781<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]782 <a name="globalvars">Global Variables</a>
783</div>
784
785<div class="doc_text">
786
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]787<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]788 instead of run-time. Global variables may optionally be initialized, may
789 have an explicit section to be placed in, and may have an optional explicit
790 alignment specified. A variable may be defined as "thread_local", which
791 means that it will not be shared by threads (each thread will have a
792 separated copy of the variable). A variable may be defined as a global
793 "constant," which indicates that the contents of the variable
794 will <b>never</b> be modified (enabling better optimization, allowing the
795 global data to be placed in the read-only section of an executable, etc).
796 Note that variables that need runtime initialization cannot be marked
797 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]798
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]799<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
800 constant, even if the final definition of the global is not. This capability
801 can be used to enable slightly better optimization of the program, but
802 requires the language definition to guarantee that optimizations based on the
803 'constantness' are valid for the translation units that do not include the
804 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]805
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]806<p>As SSA values, global variables define pointer values that are in scope
807 (i.e. they dominate) all basic blocks in the program. Global variables
808 always define a pointer to their "content" type because they describe a
809 region of memory, and all memory objects in LLVM are accessed through
810 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]811
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]812<p>A global variable may be declared to reside in a target-specific numbered
813 address space. For targets that support them, address spaces may affect how
814 optimizations are performed and/or what target instructions are used to
815 access the variable. The default address space is zero. The address space
816 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]817
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]818<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]819 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]820
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]821<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]822 the alignment is set to zero, the alignment of the global is set by the
823 target to whatever it feels convenient. If an explicit alignment is
824 specified, the global is forced to have at least that much alignment. All
825 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]826
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]827<p>For example, the following defines a global in a numbered address space with
828 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]829
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]830<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]831<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]832@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]833</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]834</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]835
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]836</div>
837
838
839<!-- ======================================================================= -->
840<div class="doc_subsection">
841 <a name="functionstructure">Functions</a>
842</div>
843
844<div class="doc_text">
845
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]846<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
847 optional <a href="#linkage">linkage type</a>, an optional
848 <a href="#visibility">visibility style</a>, an optional
849 <a href="#callingconv">calling convention</a>, a return type, an optional
850 <a href="#paramattrs">parameter attribute</a> for the return type, a function
851 name, a (possibly empty) argument list (each with optional
852 <a href="#paramattrs">parameter attributes</a>), optional
853 <a href="#fnattrs">function attributes</a>, an optional section, an optional
854 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
855 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]856
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]857<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
858 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]859 <a href="#visibility">visibility style</a>, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]860 <a href="#callingconv">calling convention</a>, a return type, an optional
861 <a href="#paramattrs">parameter attribute</a> for the return type, a function
862 name, a possibly empty list of arguments, an optional alignment, and an
863 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]864
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]865<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]866 (Control Flow Graph) for the function. Each basic block may optionally start
867 with a label (giving the basic block a symbol table entry), contains a list
868 of instructions, and ends with a <a href="#terminators">terminator</a>
869 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]870
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]871<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]872 executed on entrance to the function, and it is not allowed to have
873 predecessor basic blocks (i.e. there can not be any branches to the entry
874 block of a function). Because the block can have no predecessors, it also
875 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]876
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]877<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]878 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]879
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]880<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]881 the alignment is set to zero, the alignment of the function is set by the
882 target to whatever it feels convenient. If an explicit alignment is
883 specified, the function is forced to have at least that much alignment. All
884 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]885
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]886<h5>Syntax:</h5>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]887<div class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]888<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]889define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]890 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
891 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
892 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
893 [<a href="#gc">gc</a>] { ... }
894</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]895</div>
896
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]897</div>
898
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]899<!-- ======================================================================= -->
900<div class="doc_subsection">
901 <a name="aliasstructure">Aliases</a>
902</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]903
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]904<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]905
906<p>Aliases act as "second name" for the aliasee value (which can be either
907 function, global variable, another alias or bitcast of global value). Aliases
908 may have an optional <a href="#linkage">linkage type</a>, and an
909 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]910
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]911<h5>Syntax:</h5>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]912<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]913<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]914@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]915</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]916</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]917
918</div>
919
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]920<!-- ======================================================================= -->
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]921<div class="doc_subsection">
922 <a name="namedmetadatastructure">Named Metadata</a>
923</div>
924
925<div class="doc_text">
926
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame^]927<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
928 nodes</a> (but not metadata strings) and null are the only valid operands for
929 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]930
931<h5>Syntax:</h5>
932<div class="doc_code">
933<pre>
934!1 = metadata !{metadata !"one"}
935!name = !{null, !1}
936</pre>
937</div>
938
939</div>
940
941<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]942<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]943
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]944<div class="doc_text">
945
946<p>The return type and each parameter of a function type may have a set of
947 <i>parameter attributes</i> associated with them. Parameter attributes are
948 used to communicate additional information about the result or parameters of
949 a function. Parameter attributes are considered to be part of the function,
950 not of the function type, so functions with different parameter attributes
951 can have the same function type.</p>
952
953<p>Parameter attributes are simple keywords that follow the type specified. If
954 multiple parameter attributes are needed, they are space separated. For
955 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]956
957<div class="doc_code">
958<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]959declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]960declare i32 @atoi(i8 zeroext)
961declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]962</pre>
963</div>
964
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]965<p>Note that any attributes for the function result (<tt>nounwind</tt>,
966 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]967
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]968<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]969
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]970<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]971 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]972 <dd>This indicates to the code generator that the parameter or return value
973 should be zero-extended to a 32-bit value by the caller (for a parameter)
974 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]975
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]976 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]977 <dd>This indicates to the code generator that the parameter or return value
978 should be sign-extended to a 32-bit value by the caller (for a parameter)
979 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]980
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]981 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]982 <dd>This indicates that this parameter or return value should be treated in a
983 special target-dependent fashion during while emitting code for a function
984 call or return (usually, by putting it in a register as opposed to memory,
985 though some targets use it to distinguish between two different kinds of
986 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]987
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]988 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]989 <dd>This indicates that the pointer parameter should really be passed by value
990 to the function. The attribute implies that a hidden copy of the pointee
991 is made between the caller and the callee, so the callee is unable to
992 modify the value in the callee. This attribute is only valid on LLVM
993 pointer arguments. It is generally used to pass structs and arrays by
994 value, but is also valid on pointers to scalars. The copy is considered
995 to belong to the caller not the callee (for example,
996 <tt><a href="#readonly">readonly</a></tt> functions should not write to
997 <tt>byval</tt> parameters). This is not a valid attribute for return
998 values. The byval attribute also supports specifying an alignment with
999 the align attribute. This has a target-specific effect on the code
1000 generator that usually indicates a desired alignment for the synthesized
1001 stack slot.</dd>
1002
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1003 <dt><tt><b>sret</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1004 <dd>This indicates that the pointer parameter specifies the address of a
1005 structure that is the return value of the function in the source program.
1006 This pointer must be guaranteed by the caller to be valid: loads and
1007 stores to the structure may be assumed by the callee to not to trap. This
1008 may only be applied to the first parameter. This is not a valid attribute
1009 for return values. </dd>
1010
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1011 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1012 <dd>This indicates that the pointer does not alias any global or any other
1013 parameter. The caller is responsible for ensuring that this is the
1014 case. On a function return value, <tt>noalias</tt> additionally indicates
1015 that the pointer does not alias any other pointers visible to the
1016 caller. For further details, please see the discussion of the NoAlias
1017 response in
1018 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1019 analysis</a>.</dd>
1020
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1021 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1022 <dd>This indicates that the callee does not make any copies of the pointer
1023 that outlive the callee itself. This is not a valid attribute for return
1024 values.</dd>
1025
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1026 <dt><tt><b>nest</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1027 <dd>This indicates that the pointer parameter can be excised using the
1028 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1029 attribute for return values.</dd>
1030</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1031
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1032</div>
1033
1034<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1035<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1036 <a name="gc">Garbage Collector Names</a>
1037</div>
1038
1039<div class="doc_text">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1040
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1041<p>Each function may specify a garbage collector name, which is simply a
1042 string:</p>
1043
1044<div class="doc_code">
1045<pre>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1046define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1047</pre>
1048</div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1049
1050<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1051 collector which will cause the compiler to alter its output in order to
1052 support the named garbage collection algorithm.</p>
1053
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1054</div>
1055
1056<!-- ======================================================================= -->
1057<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1058 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1059</div>
1060
1061<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1062
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1063<p>Function attributes are set to communicate additional information about a
1064 function. Function attributes are considered to be part of the function, not
1065 of the function type, so functions with different parameter attributes can
1066 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1067
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1068<p>Function attributes are simple keywords that follow the type specified. If
1069 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1070
1071<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1072<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1073define void @f() noinline { ... }
1074define void @f() alwaysinline { ... }
1075define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1076define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1077</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1078</div>
1079
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1080<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1081 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1082 <dd>This attribute indicates that the inliner should attempt to inline this
1083 function into callers whenever possible, ignoring any active inlining size
1084 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1085
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1086 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1087 <dd>This attribute indicates that the inliner should never inline this
1088 function in any situation. This attribute may not be used together with
1089 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1090
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1091 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1092 <dd>This attribute suggests that optimization passes and code generator passes
1093 make choices that keep the code size of this function low, and otherwise
1094 do optimizations specifically to reduce code size.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1095
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1096 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1097 <dd>This function attribute indicates that the function never returns
1098 normally. This produces undefined behavior at runtime if the function
1099 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1100
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1101 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1102 <dd>This function attribute indicates that the function never returns with an
1103 unwind or exceptional control flow. If the function does unwind, its
1104 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1105
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1106 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1107 <dd>This attribute indicates that the function computes its result (or decides
1108 to unwind an exception) based strictly on its arguments, without
1109 dereferencing any pointer arguments or otherwise accessing any mutable
1110 state (e.g. memory, control registers, etc) visible to caller functions.
1111 It does not write through any pointer arguments
1112 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1113 changes any state visible to callers. This means that it cannot unwind
1114 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1115 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1116
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1117 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1118 <dd>This attribute indicates that the function does not write through any
1119 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1120 arguments) or otherwise modify any state (e.g. memory, control registers,
1121 etc) visible to caller functions. It may dereference pointer arguments
1122 and read state that may be set in the caller. A readonly function always
1123 returns the same value (or unwinds an exception identically) when called
1124 with the same set of arguments and global state. It cannot unwind an
1125 exception by calling the <tt>C++</tt> exception throwing methods, but may
1126 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1127
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1128 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1129 <dd>This attribute indicates that the function should emit a stack smashing
1130 protector. It is in the form of a "canary"&mdash;a random value placed on
1131 the stack before the local variables that's checked upon return from the
1132 function to see if it has been overwritten. A heuristic is used to
1133 determine if a function needs stack protectors or not.<br>
1134<br>
1135 If a function that has an <tt>ssp</tt> attribute is inlined into a
1136 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1137 function will have an <tt>ssp</tt> attribute.</dd>
1138
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1139 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1140 <dd>This attribute indicates that the function should <em>always</em> emit a
1141 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1142 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1143<br>
1144 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1145 function that doesn't have an <tt>sspreq</tt> attribute or which has
1146 an <tt>ssp</tt> attribute, then the resulting function will have
1147 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1148
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1149 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1150 <dd>This attribute indicates that the code generator should not use a red
1151 zone, even if the target-specific ABI normally permits it.</dd>
1152
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1153 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1154 <dd>This attributes disables implicit floating point instructions.</dd>
1155
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1156 <dt><tt><b>naked</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1157 <dd>This attribute disables prologue / epilogue emission for the function.
1158 This can have very system-specific consequences.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1159</dl>
1160
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1161</div>
1162
1163<!-- ======================================================================= -->
1164<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1165 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1166</div>
1167
1168<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1169
1170<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1171 the GCC "file scope inline asm" blocks. These blocks are internally
1172 concatenated by LLVM and treated as a single unit, but may be separated in
1173 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1174
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1175<div class="doc_code">
1176<pre>
1177module asm "inline asm code goes here"
1178module asm "more can go here"
1179</pre>
1180</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1181
1182<p>The strings can contain any character by escaping non-printable characters.
1183 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]1184 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1185
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1186<p>The inline asm code is simply printed to the machine code .s file when
1187 assembly code is generated.</p>
1188
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1189</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1190
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1191<!-- ======================================================================= -->
1192<div class="doc_subsection">
1193 <a name="datalayout">Data Layout</a>
1194</div>
1195
1196<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1197
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1198<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 data is to be laid out in memory. The syntax for the data layout is
1200 simply:</p>
1201
1202<div class="doc_code">
1203<pre>
1204target datalayout = "<i>layout specification</i>"
1205</pre>
1206</div>
1207
1208<p>The <i>layout specification</i> consists of a list of specifications
1209 separated by the minus sign character ('-'). Each specification starts with
1210 a letter and may include other information after the letter to define some
1211 aspect of the data layout. The specifications accepted are as follows:</p>
1212
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1213<dl>
1214 <dt><tt>E</tt></dt>
1215 <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]1216 bits with the most significance have the lowest address location.</dd>
1217
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1218 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1219 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1220 the bits with the least significance have the lowest address
1221 location.</dd>
1222
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1223 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1224 <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]1225 <i>preferred</i> alignments. All sizes are in bits. Specifying
1226 the <i>pref</i> alignment is optional. If omitted, the
1227 preceding <tt>:</tt> should be omitted too.</dd>
1228
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1229 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1230 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1231 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1232
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1233 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1234 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1235 <i>size</i>.</dd>
1236
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1237 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1238 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1239 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1240 (double).</dd>
1241
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1242 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1243 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1244 <i>size</i>.</dd>
1245
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1246 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1247 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1248 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1249
1250 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1251 <dd>This specifies a set of native integer widths for the target CPU
1252 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1253 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1254 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1255 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1256</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1257
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1258<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1259 default set of specifications which are then (possibly) overriden by the
1260 specifications in the <tt>datalayout</tt> keyword. The default specifications
1261 are given in this list:</p>
1262
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1263<ul>
1264 <li><tt>E</tt> - big endian</li>
1265 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1266 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1267 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1268 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1269 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1270 <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]1271 alignment of 64-bits</li>
1272 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1273 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1274 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1275 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1276 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1277 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1278</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1279
1280<p>When LLVM is determining the alignment for a given type, it uses the
1281 following rules:</p>
1282
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1283<ol>
1284 <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]1285 specification is used.</li>
1286
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1287 <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]1288 smallest integer type that is larger than the bitwidth of the sought type
1289 is used. If none of the specifications are larger than the bitwidth then
1290 the the largest integer type is used. For example, given the default
1291 specifications above, the i7 type will use the alignment of i8 (next
1292 largest) while both i65 and i256 will use the alignment of i64 (largest
1293 specified).</li>
1294
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1295 <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]1296 largest vector type that is smaller than the sought vector type will be
1297 used as a fall back. This happens because &lt;128 x double&gt; can be
1298 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1299</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1300
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1301</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1302
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1303<!-- ======================================================================= -->
1304<div class="doc_subsection">
1305 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1306</div>
1307
1308<div class="doc_text">
1309
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1310<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1311with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1312is undefined. Pointer values are associated with address ranges
1313according to the following rules:</p>
1314
1315<ul>
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1316 <li>A pointer value formed from a
1317 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1318 is associated with the addresses associated with the first operand
1319 of the <tt>getelementptr</tt>.</li>
1320 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1321 range of the variable's storage.</li>
1322 <li>The result value of an allocation instruction is associated with
1323 the address range of the allocated storage.</li>
1324 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1325 no address.</li>
1326 <li>A pointer value formed by an
1327 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1328 address ranges of all pointer values that contribute (directly or
1329 indirectly) to the computation of the pointer's value.</li>
1330 <li>The result value of a
1331 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1332 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1333 <li>An integer constant other than zero or a pointer value returned
1334 from a function not defined within LLVM may be associated with address
1335 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1336 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1337 allocated by mechanisms provided by LLVM.</li>
1338 </ul>
1339
1340<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1341<tt><a href="#i_load">load</a></tt> merely indicates the size and
1342alignment of the memory from which to load, as well as the
1343interpretation of the value. The first operand of a
1344<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1345and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1346
1347<p>Consequently, type-based alias analysis, aka TBAA, aka
1348<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1349LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1350additional information which specialized optimization passes may use
1351to implement type-based alias analysis.</p>
1352
1353</div>
1354
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1355<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1356<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1357<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1358
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1359<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1360
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1361<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1362 intermediate representation. Being typed enables a number of optimizations
1363 to be performed on the intermediate representation directly, without having
1364 to do extra analyses on the side before the transformation. A strong type
1365 system makes it easier to read the generated code and enables novel analyses
1366 and transformations that are not feasible to perform on normal three address
1367 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1368
1369</div>
1370
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1371<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1372<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1373Classifications</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1374
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1375<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1376
1377<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1378
1379<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1380 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1381 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1382 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1383 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1384 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1385 </tr>
1386 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1387 <td><a href="#t_floating">floating point</a></td>
1388 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1389 </tr>
1390 <tr>
1391 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1392 <td><a href="#t_integer">integer</a>,
1393 <a href="#t_floating">floating point</a>,
1394 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1395 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1396 <a href="#t_struct">structure</a>,
1397 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1398 <a href="#t_label">label</a>,
1399 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1400 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1401 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1402 <tr>
1403 <td><a href="#t_primitive">primitive</a></td>
1404 <td><a href="#t_label">label</a>,
1405 <a href="#t_void">void</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1406 <a href="#t_floating">floating point</a>,
1407 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1408 </tr>
1409 <tr>
1410 <td><a href="#t_derived">derived</a></td>
1411 <td><a href="#t_integer">integer</a>,
1412 <a href="#t_array">array</a>,
1413 <a href="#t_function">function</a>,
1414 <a href="#t_pointer">pointer</a>,
1415 <a href="#t_struct">structure</a>,
1416 <a href="#t_pstruct">packed structure</a>,
1417 <a href="#t_vector">vector</a>,
1418 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1419 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1420 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1421 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1422</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1423
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1424<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1425 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1426 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1427
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1428</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1429
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1430<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1431<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1432
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1433<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1434
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1435<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1436 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1437
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1438</div>
1439
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1440<!-- _______________________________________________________________________ -->
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1441<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1442
1443<div class="doc_text">
1444
1445<h5>Overview:</h5>
1446<p>The integer type is a very simple type that simply specifies an arbitrary
1447 bit width for the integer type desired. Any bit width from 1 bit to
1448 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1449
1450<h5>Syntax:</h5>
1451<pre>
1452 iN
1453</pre>
1454
1455<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1456 value.</p>
1457
1458<h5>Examples:</h5>
1459<table class="layout">
1460 <tr class="layout">
1461 <td class="left"><tt>i1</tt></td>
1462 <td class="left">a single-bit integer.</td>
1463 </tr>
1464 <tr class="layout">
1465 <td class="left"><tt>i32</tt></td>
1466 <td class="left">a 32-bit integer.</td>
1467 </tr>
1468 <tr class="layout">
1469 <td class="left"><tt>i1942652</tt></td>
1470 <td class="left">a really big integer of over 1 million bits.</td>
1471 </tr>
1472</table>
1473
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1474</div>
1475
1476<!-- _______________________________________________________________________ -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1477<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1478
1479<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1480
1481<table>
1482 <tbody>
1483 <tr><th>Type</th><th>Description</th></tr>
1484 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1485 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1486 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1487 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1488 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1489 </tbody>
1490</table>
1491
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1492</div>
1493
1494<!-- _______________________________________________________________________ -->
1495<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1496
1497<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1498
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1499<h5>Overview:</h5>
1500<p>The void type does not represent any value and has no size.</p>
1501
1502<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1503<pre>
1504 void
1505</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1506
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1507</div>
1508
1509<!-- _______________________________________________________________________ -->
1510<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1511
1512<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1513
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1514<h5>Overview:</h5>
1515<p>The label type represents code labels.</p>
1516
1517<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1518<pre>
1519 label
1520</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1521
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1522</div>
1523
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1524<!-- _______________________________________________________________________ -->
1525<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1526
1527<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1528
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1529<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1530<p>The metadata type represents embedded metadata. No derived types may be
1531 created from metadata except for <a href="#t_function">function</a>
1532 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1533
1534<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1535<pre>
1536 metadata
1537</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1538
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1539</div>
1540
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1541
1542<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1543<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1544
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1545<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1546
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1547<p>The real power in LLVM comes from the derived types in the system. This is
1548 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1549 useful types. Each of these types contain one or more element types which
1550 may be a primitive type, or another derived type. For example, it is
1551 possible to have a two dimensional array, using an array as the element type
1552 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1553
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1554</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1555
1556<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1557<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1558
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1559<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1560
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1561<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1562<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1563 sequentially in memory. The array type requires a size (number of elements)
1564 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1565
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1566<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1567<pre>
1568 [&lt;# elements&gt; x &lt;elementtype&gt;]
1569</pre>
1570
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1571<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1572 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1573
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1574<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1575<table class="layout">
1576 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1577 <td class="left"><tt>[40 x i32]</tt></td>
1578 <td class="left">Array of 40 32-bit integer values.</td>
1579 </tr>
1580 <tr class="layout">
1581 <td class="left"><tt>[41 x i32]</tt></td>
1582 <td class="left">Array of 41 32-bit integer values.</td>
1583 </tr>
1584 <tr class="layout">
1585 <td class="left"><tt>[4 x i8]</tt></td>
1586 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1587 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1588</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1589<p>Here are some examples of multidimensional arrays:</p>
1590<table class="layout">
1591 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1592 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1593 <td class="left">3x4 array of 32-bit integer values.</td>
1594 </tr>
1595 <tr class="layout">
1596 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1597 <td class="left">12x10 array of single precision floating point values.</td>
1598 </tr>
1599 <tr class="layout">
1600 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1601 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1602 </tr>
1603</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1604
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1605<p>There is no restriction on indexing beyond the end of the array implied by
1606 a static type (though there are restrictions on indexing beyond the bounds
1607 of an allocated object in some cases). This means that single-dimension
1608 'variable sized array' addressing can be implemented in LLVM with a zero
1609 length array type. An implementation of 'pascal style arrays' in LLVM could
1610 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1611
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1612</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1613
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1614<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1615<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1616
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1617<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1618
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1619<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1620<p>The function type can be thought of as a function signature. It consists of
1621 a return type and a list of formal parameter types. The return type of a
1622 function type is a scalar type, a void type, or a struct type. If the return
1623 type is a struct type then all struct elements must be of first class types,
1624 and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1625
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1626<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1627<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1628 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1629</pre>
1630
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1631<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]1632 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1633 which indicates that the function takes a variable number of arguments.
1634 Variable argument functions can access their arguments with
1635 the <a href="#int_varargs">variable argument handling intrinsic</a>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1636 functions. '<tt>&lt;returntype&gt;</tt>' is a any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1637 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1638
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1639<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1640<table class="layout">
1641 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1642 <td class="left"><tt>i32 (i32)</tt></td>
1643 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1644 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1645 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1646 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1647 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1648 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1649 an <tt>i16</tt> that should be sign extended and a
1650 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1651 <tt>float</tt>.
1652 </td>
1653 </tr><tr class="layout">
1654 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1655 <td class="left">A vararg function that takes at least one
1656 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1657 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1658 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1659 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1660 </tr><tr class="layout">
1661 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1662 <td class="left">A function taking an <tt>i32</tt>, returning a
1663 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1664 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1665 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1666</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1667
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1668</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1669
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1670<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1671<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1672
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1673<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1674
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1675<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1676<p>The structure type is used to represent a collection of data members together
1677 in memory. The packing of the field types is defined to match the ABI of the
1678 underlying processor. The elements of a structure may be any type that has a
1679 size.</p>
1680
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1681<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1682 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1683 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1684 Structures in registers are accessed using the
1685 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1686 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1687<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1688<pre>
1689 { &lt;type list&gt; }
1690</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1691
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1692<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1693<table class="layout">
1694 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1695 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1696 <td class="left">A triple of three <tt>i32</tt> values</td>
1697 </tr><tr class="layout">
1698 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1699 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1700 second element is a <a href="#t_pointer">pointer</a> to a
1701 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1702 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1703 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1704</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1705
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1706</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1707
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1708<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1709<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1710</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1711
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1712<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1713
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1714<h5>Overview:</h5>
1715<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1716 together in memory. There is no padding between fields. Further, the
1717 alignment of a packed structure is 1 byte. The elements of a packed
1718 structure may be any type that has a size.</p>
1719
1720<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1721 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1722 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1723
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1724<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1725<pre>
1726 &lt; { &lt;type list&gt; } &gt;
1727</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1728
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1729<h5>Examples:</h5>
1730<table class="layout">
1731 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1732 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1733 <td class="left">A triple of three <tt>i32</tt> values</td>
1734 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1735 <td class="left">
1736<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1737 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1738 second element is a <a href="#t_pointer">pointer</a> to a
1739 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1740 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1741 </tr>
1742</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1743
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1744</div>
1745
1746<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1747<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1748
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1749<div class="doc_text">
1750
1751<h5>Overview:</h5>
1752<p>As in many languages, the pointer type represents a pointer or reference to
1753 another object, which must live in memory. Pointer types may have an optional
1754 address space attribute defining the target-specific numbered address space
1755 where the pointed-to object resides. The default address space is zero.</p>
1756
1757<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1758 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1759
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1760<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1761<pre>
1762 &lt;type&gt; *
1763</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1764
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1765<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1766<table class="layout">
1767 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1768 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1769 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1770 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1771 </tr>
1772 <tr class="layout">
1773 <td class="left"><tt>i32 (i32 *) *</tt></td>
1774 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1775 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1776 <tt>i32</tt>.</td>
1777 </tr>
1778 <tr class="layout">
1779 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1780 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1781 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1782 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1783</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1784
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1785</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1786
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1787<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1788<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1789
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1790<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1791
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1792<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1793<p>A vector type is a simple derived type that represents a vector of elements.
1794 Vector types are used when multiple primitive data are operated in parallel
1795 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1796 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1797 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1798
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1799<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1800<pre>
1801 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1802</pre>
1803
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1804<p>The number of elements is a constant integer value; elementtype may be any
1805 integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1806
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1807<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +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>&lt;4 x i32&gt;</tt></td>
1811 <td class="left">Vector of 4 32-bit integer values.</td>
1812 </tr>
1813 <tr class="layout">
1814 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1815 <td class="left">Vector of 8 32-bit floating-point values.</td>
1816 </tr>
1817 <tr class="layout">
1818 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1819 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1820 </tr>
1821</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1822
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1823</div>
1824
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1825<!-- _______________________________________________________________________ -->
1826<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1827<div class="doc_text">
1828
1829<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1830<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1831 corresponds (for example) to the C notion of a forward declared structure
1832 type. In LLVM, opaque types can eventually be resolved to any type (not just
1833 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1834
1835<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1836<pre>
1837 opaque
1838</pre>
1839
1840<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1841<table class="layout">
1842 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1843 <td class="left"><tt>opaque</tt></td>
1844 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1845 </tr>
1846</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1847
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1848</div>
1849
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1850<!-- ======================================================================= -->
1851<div class="doc_subsection">
1852 <a name="t_uprefs">Type Up-references</a>
1853</div>
1854
1855<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1856
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1857<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1858<p>An "up reference" allows you to refer to a lexically enclosing type without
1859 requiring it to have a name. For instance, a structure declaration may
1860 contain a pointer to any of the types it is lexically a member of. Example
1861 of up references (with their equivalent as named type declarations)
1862 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1863
1864<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1865 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1866 { \2 }* %y = type { %y }*
1867 \1* %z = type %z*
1868</pre>
1869
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1870<p>An up reference is needed by the asmprinter for printing out cyclic types
1871 when there is no declared name for a type in the cycle. Because the
1872 asmprinter does not want to print out an infinite type string, it needs a
1873 syntax to handle recursive types that have no names (all names are optional
1874 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1875
1876<h5>Syntax:</h5>
1877<pre>
1878 \&lt;level&gt;
1879</pre>
1880
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1881<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]1882
1883<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1884<table class="layout">
1885 <tr class="layout">
1886 <td class="left"><tt>\1*</tt></td>
1887 <td class="left">Self-referential pointer.</td>
1888 </tr>
1889 <tr class="layout">
1890 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1891 <td class="left">Recursive structure where the upref refers to the out-most
1892 structure.</td>
1893 </tr>
1894</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1895
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1896</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1897
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1898<!-- *********************************************************************** -->
1899<div class="doc_section"> <a name="constants">Constants</a> </div>
1900<!-- *********************************************************************** -->
1901
1902<div class="doc_text">
1903
1904<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1905 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1906
1907</div>
1908
1909<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1910<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1911
1912<div class="doc_text">
1913
1914<dl>
1915 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1916 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1917 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1918
1919 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1920 <dd>Standard integers (such as '4') are constants of
1921 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1922 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1923
1924 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1925 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1926 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1927 notation (see below). The assembler requires the exact decimal value of a
1928 floating-point constant. For example, the assembler accepts 1.25 but
1929 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1930 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1931
1932 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1933 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1934 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1935</dl>
1936
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1937<p>The one non-intuitive notation for constants is the hexadecimal form of
1938 floating point constants. For example, the form '<tt>double
1939 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1940 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1941 constants are required (and the only time that they are generated by the
1942 disassembler) is when a floating point constant must be emitted but it cannot
1943 be represented as a decimal floating point number in a reasonable number of
1944 digits. For example, NaN's, infinities, and other special values are
1945 represented in their IEEE hexadecimal format so that assembly and disassembly
1946 do not cause any bits to change in the constants.</p>
1947
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]1948<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1949 represented using the 16-digit form shown above (which matches the IEEE754
1950 representation for double); float values must, however, be exactly
1951 representable as IEE754 single precision. Hexadecimal format is always used
1952 for long double, and there are three forms of long double. The 80-bit format
1953 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1954 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1955 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1956 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1957 currently supported target uses this format. Long doubles will only work if
1958 they match the long double format on your target. All hexadecimal formats
1959 are big-endian (sign bit at the left).</p>
1960
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1961</div>
1962
1963<!-- ======================================================================= -->
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1964<div class="doc_subsection">
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]1965<a name="aggregateconstants"></a> <!-- old anchor -->
1966<a name="complexconstants">Complex Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1967</div>
1968
1969<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1970
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1971<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1972 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1973
1974<dl>
1975 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1976 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1977 type definitions (a comma separated list of elements, surrounded by braces
1978 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1979 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1980 Structure constants must have <a href="#t_struct">structure type</a>, and
1981 the number and types of elements must match those specified by the
1982 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1983
1984 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1985 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1986 definitions (a comma separated list of elements, surrounded by square
1987 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1988 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1989 the number and types of elements must match those specified by the
1990 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1991
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1992 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1993 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1994 definitions (a comma separated list of elements, surrounded by
1995 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1996 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1997 have <a href="#t_vector">vector type</a>, and the number and types of
1998 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1999
2000 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2001 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2002 value to zero of <em>any</em> type, including scalar and aggregate types.
2003 This is often used to avoid having to print large zero initializers
2004 (e.g. for large arrays) and is always exactly equivalent to using explicit
2005 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2006
2007 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2008 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2009 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2010 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2011 be interpreted as part of the instruction stream, metadata is a place to
2012 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2013</dl>
2014
2015</div>
2016
2017<!-- ======================================================================= -->
2018<div class="doc_subsection">
2019 <a name="globalconstants">Global Variable and Function Addresses</a>
2020</div>
2021
2022<div class="doc_text">
2023
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2024<p>The addresses of <a href="#globalvars">global variables</a>
2025 and <a href="#functionstructure">functions</a> are always implicitly valid
2026 (link-time) constants. These constants are explicitly referenced when
2027 the <a href="#identifiers">identifier for the global</a> is used and always
2028 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2029 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2030
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2031<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2032<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2033@X = global i32 17
2034@Y = global i32 42
2035@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2036</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2037</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2038
2039</div>
2040
2041<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]2042<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2043<div class="doc_text">
2044
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2045<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]2046 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2047 Undefined values may be of any type (other than label or void) and be used
2048 anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2049
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2050<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2051 program is well defined no matter what value is used. This gives the
2052 compiler more freedom to optimize. Here are some examples of (potentially
2053 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2054
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2055
2056<div class="doc_code">
2057<pre>
2058 %A = add %X, undef
2059 %B = sub %X, undef
2060 %C = xor %X, undef
2061Safe:
2062 %A = undef
2063 %B = undef
2064 %C = undef
2065</pre>
2066</div>
2067
2068<p>This is safe because all of the output bits are affected by the undef bits.
2069Any output bit can have a zero or one depending on the input bits.</p>
2070
2071<div class="doc_code">
2072<pre>
2073 %A = or %X, undef
2074 %B = and %X, undef
2075Safe:
2076 %A = -1
2077 %B = 0
2078Unsafe:
2079 %A = undef
2080 %B = undef
2081</pre>
2082</div>
2083
2084<p>These logical operations have bits that are not always affected by the input.
2085For example, if "%X" has a zero bit, then the output of the 'and' operation will
2086always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2087such, it is unsafe to optimize or assume that the result of the and is undef.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2088However, it is safe to assume that all bits of the undef could be 0, and
2089optimize the and to 0. Likewise, it is safe to assume that all the bits of
2090the undef operand to the or could be set, allowing the or to be folded to
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2091-1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2092
2093<div class="doc_code">
2094<pre>
2095 %A = select undef, %X, %Y
2096 %B = select undef, 42, %Y
2097 %C = select %X, %Y, undef
2098Safe:
2099 %A = %X (or %Y)
2100 %B = 42 (or %Y)
2101 %C = %Y
2102Unsafe:
2103 %A = undef
2104 %B = undef
2105 %C = undef
2106</pre>
2107</div>
2108
2109<p>This set of examples show that undefined select (and conditional branch)
2110conditions can go "either way" but they have to come from one of the two
2111operands. In the %A example, if %X and %Y were both known to have a clear low
2112bit, then %A would have to have a cleared low bit. However, in the %C example,
2113the optimizer is allowed to assume that the undef operand could be the same as
2114%Y, allowing the whole select to be eliminated.</p>
2115
2116
2117<div class="doc_code">
2118<pre>
2119 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2120
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2121 %B = undef
2122 %C = xor %B, %B
2123
2124 %D = undef
2125 %E = icmp lt %D, 4
2126 %F = icmp gte %D, 4
2127
2128Safe:
2129 %A = undef
2130 %B = undef
2131 %C = undef
2132 %D = undef
2133 %E = undef
2134 %F = undef
2135</pre>
2136</div>
2137
2138<p>This example points out that two undef operands are not necessarily the same.
2139This can be surprising to people (and also matches C semantics) where they
2140assume that "X^X" is always zero, even if X is undef. This isn't true for a
2141number of reasons, but the short answer is that an undef "variable" can
2142arbitrarily change its value over its "live range". This is true because the
2143"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2144logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2145so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner6760e542009-09-08 15:13:16 +0000[diff] [blame]2146to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2147would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2148
2149<div class="doc_code">
2150<pre>
2151 %A = fdiv undef, %X
2152 %B = fdiv %X, undef
2153Safe:
2154 %A = undef
2155b: unreachable
2156</pre>
2157</div>
2158
2159<p>These examples show the crucial difference between an <em>undefined
2160value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2161allowed to have an arbitrary bit-pattern. This means that the %A operation
2162can be constant folded to undef because the undef could be an SNaN, and fdiv is
2163not (currently) defined on SNaN's. However, in the second example, we can make
2164a more aggressive assumption: because the undef is allowed to be an arbitrary
2165value, 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]2166has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2167does not execute at all. This allows us to delete the divide and all code after
2168it: since the undefined operation "can't happen", the optimizer can assume that
2169it occurs in dead code.
2170</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2171
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2172<div class="doc_code">
2173<pre>
2174a: store undef -> %X
2175b: store %X -> undef
2176Safe:
2177a: &lt;deleted&gt;
2178b: unreachable
2179</pre>
2180</div>
2181
2182<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2183can be assumed to not have any effect: we can assume that the value is
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2184overwritten with bits that happen to match what was already there. However, a
2185store "to" an undefined location could clobber arbitrary memory, therefore, it
2186has undefined behavior.</p>
2187
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2188</div>
2189
2190<!-- ======================================================================= -->
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2191<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2192 Blocks</a></div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2193<div class="doc_text">
2194
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2195<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2196
2197<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2198 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2199 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2200
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2201<p>This value only has defined behavior when used as an operand to the
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2202 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2203 against null. Pointer equality tests between labels addresses is undefined
2204 behavior - though, again, comparison against null is ok, and no label is
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2205 equal to the null pointer. This may also be passed around as an opaque
2206 pointer sized value as long as the bits are not inspected. This allows
Chris Lattnerda37b302009-10-27 21:44:20 +0000[diff] [blame]2207 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2208 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2209
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2210<p>Finally, some targets may provide defined semantics when
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2211 using the value as the operand to an inline assembly, but that is target
2212 specific.
2213 </p>
2214
2215</div>
2216
2217
2218<!-- ======================================================================= -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2219<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2220</div>
2221
2222<div class="doc_text">
2223
2224<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2225 to be used as constants. Constant expressions may be of
2226 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2227 operation that does not have side effects (e.g. load and call are not
2228 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2229
2230<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2231 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2232 <dd>Truncate a constant to another type. The bit size of CST must be larger
2233 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2234
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2235 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2236 <dd>Zero extend a constant to another type. The bit size of CST must be
2237 smaller or equal to the bit size of TYPE. Both types must be
2238 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2239
2240 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2241 <dd>Sign extend a constant to another type. The bit size of CST must be
2242 smaller or equal to the bit size of TYPE. Both types must be
2243 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2244
2245 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2246 <dd>Truncate a floating point constant to another floating point type. The
2247 size of CST must be larger than the size of TYPE. Both types must be
2248 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2249
2250 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2251 <dd>Floating point extend a constant to another type. The size of CST must be
2252 smaller or equal to the size of TYPE. Both types must be floating
2253 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2254
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]2255 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2256 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2257 constant. TYPE must be a scalar or vector integer type. CST must be of
2258 scalar or vector floating point type. Both CST and TYPE must be scalars,
2259 or vectors of the same number of elements. If the value won't fit in the
2260 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2261
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2262 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2263 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2264 constant. TYPE must be a scalar or vector integer type. CST must be of
2265 scalar or vector floating point type. Both CST and TYPE must be scalars,
2266 or vectors of the same number of elements. If the value won't fit in the
2267 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2268
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2269 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2270 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2271 constant. TYPE must be a scalar or vector floating point type. CST must be
2272 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2273 vectors of the same number of elements. If the value won't fit in the
2274 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2275
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2276 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2277 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2278 constant. TYPE must be a scalar or vector floating point type. CST must be
2279 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2280 vectors of the same number of elements. If the value won't fit in the
2281 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2282
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2283 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2284 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2285 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2286 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2287 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2288
2289 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2290 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2291 type. CST must be of integer type. The CST value is zero extended,
2292 truncated, or unchanged to make it fit in a pointer size. This one is
2293 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2294
2295 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2296 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2297 are the same as those for the <a href="#i_bitcast">bitcast
2298 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2299
2300 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]2301 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2302 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2303 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2304 instruction, the index list may have zero or more indexes, which are
2305 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2306
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2307 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2308 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2309
2310 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2311 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2312
2313 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2314 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2315
2316 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2317 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2318 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2319
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]2320 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2321 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2322 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2323
2324 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2325 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2326 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2327
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2328 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2329 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2330 be any of the <a href="#binaryops">binary</a>
2331 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2332 on operands are the same as those for the corresponding instruction
2333 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2334</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2335
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2336</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2338<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2339<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2340<!-- *********************************************************************** -->
2341
2342<!-- ======================================================================= -->
2343<div class="doc_subsection">
2344<a name="inlineasm">Inline Assembler Expressions</a>
2345</div>
2346
2347<div class="doc_text">
2348
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2349<p>LLVM supports inline assembler expressions (as opposed
2350 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2351 a special value. This value represents the inline assembler as a string
2352 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2353 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2354 expression has side effects, and a flag indicating whether the function
2355 containing the asm needs to align its stack conservatively. An example
2356 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2357
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2358<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2359<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2360i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2361</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2362</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2363
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2364<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2365 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2366 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2367
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2368<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2369<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2370%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]2371</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2372</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2373
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2374<p>Inline asms with side effects not visible in the constraint list must be
2375 marked as having side effects. This is done through the use of the
2376 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2377
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2378<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2379<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2380call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2381</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2382</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2383
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2384<p>In some cases inline asms will contain code that will not work unless the
2385 stack is aligned in some way, such as calls or SSE instructions on x86,
2386 yet will not contain code that does that alignment within the asm.
2387 The compiler should make conservative assumptions about what the asm might
2388 contain and should generate its usual stack alignment code in the prologue
2389 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2390
2391<div class="doc_code">
2392<pre>
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2393call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2394</pre>
2395</div>
2396
2397<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2398 first.</p>
2399
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2400<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2401 documented here. Constraints on what can be done (e.g. duplication, moving,
2402 etc need to be documented). This is probably best done by reference to
2403 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2404
2405</div>
2406
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame^]2407<!-- ======================================================================= -->
2408<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2409 Strings</a>
2410</div>
2411
2412<div class="doc_text">
2413
2414<p>LLVM IR allows metadata to be attached to instructions in the program that
2415 can convey extra information about the code to the optimizers and code
2416 generator. One example application of metadata is source-level debug
2417 information. There are two metadata primitives: strings and nodes. All
2418 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2419 preceding exclamation point ('<tt>!</tt>').</p>
2420
2421<p>A metadata string is a string surrounded by double quotes. It can contain
2422 any character by escaping non-printable characters with "\xx" where "xx" is
2423 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2424
2425<p>Metadata nodes are represented with notation similar to structure constants
2426 (a comma separated list of elements, surrounded by braces and preceded by an
2427 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2428 10}</tt>". Metadata nodes can have any values as their operand.</p>
2429
2430<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2431 metadata nodes, which can be looked up in the module symbol table. For
2432 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2433
2434</div>
2435
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2436
2437<!-- *********************************************************************** -->
2438<div class="doc_section">
2439 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2440</div>
2441<!-- *********************************************************************** -->
2442
2443<p>LLVM has a number of "magic" global variables that contain data that affect
2444code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2445of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2446section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2447by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2448
2449<!-- ======================================================================= -->
2450<div class="doc_subsection">
2451<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2452</div>
2453
2454<div class="doc_text">
2455
2456<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2457href="#linkage_appending">appending linkage</a>. This array contains a list of
2458pointers to global variables and functions which may optionally have a pointer
2459cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2460
2461<pre>
2462 @X = global i8 4
2463 @Y = global i32 123
2464
2465 @llvm.used = appending global [2 x i8*] [
2466 i8* @X,
2467 i8* bitcast (i32* @Y to i8*)
2468 ], section "llvm.metadata"
2469</pre>
2470
2471<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2472compiler, assembler, and linker are required to treat the symbol as if there is
2473a reference to the global that it cannot see. For example, if a variable has
2474internal linkage and no references other than that from the <tt>@llvm.used</tt>
2475list, it cannot be deleted. This is commonly used to represent references from
2476inline asms and other things the compiler cannot "see", and corresponds to
2477"attribute((used))" in GNU C.</p>
2478
2479<p>On some targets, the code generator must emit a directive to the assembler or
2480object file to prevent the assembler and linker from molesting the symbol.</p>
2481
2482</div>
2483
2484<!-- ======================================================================= -->
2485<div class="doc_subsection">
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2486<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2487</div>
2488
2489<div class="doc_text">
2490
2491<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2492<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2493touching the symbol. On targets that support it, this allows an intelligent
2494linker to optimize references to the symbol without being impeded as it would be
2495by <tt>@llvm.used</tt>.</p>
2496
2497<p>This is a rare construct that should only be used in rare circumstances, and
2498should not be exposed to source languages.</p>
2499
2500</div>
2501
2502<!-- ======================================================================= -->
2503<div class="doc_subsection">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2504<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2505</div>
2506
2507<div class="doc_text">
2508
2509<p>TODO: Describe this.</p>
2510
2511</div>
2512
2513<!-- ======================================================================= -->
2514<div class="doc_subsection">
2515<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2516</div>
2517
2518<div class="doc_text">
2519
2520<p>TODO: Describe this.</p>
2521
2522</div>
2523
2524
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2525<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2526<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2527<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2528
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2529<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2530
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2531<p>The LLVM instruction set consists of several different classifications of
2532 instructions: <a href="#terminators">terminator
2533 instructions</a>, <a href="#binaryops">binary instructions</a>,
2534 <a href="#bitwiseops">bitwise binary instructions</a>,
2535 <a href="#memoryops">memory instructions</a>, and
2536 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2537
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2538</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2539
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2540<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2541<div class="doc_subsection"> <a name="terminators">Terminator
2542Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2543
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2544<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2545
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2546<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2547 in a program ends with a "Terminator" instruction, which indicates which
2548 block should be executed after the current block is finished. These
2549 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2550 control flow, not values (the one exception being the
2551 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2552
2553<p>There are six different terminator instructions: the
2554 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2555 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2556 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2557 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2558 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2559 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2560 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2561
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2562</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2563
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2564<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2565<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2566Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2567
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2568<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2569
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2570<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2571<pre>
2572 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]2573 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2574</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2575
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2576<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2577<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2578 a value) from a function back to the caller.</p>
2579
2580<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2581 value and then causes control flow, and one that just causes control flow to
2582 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2583
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2584<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2585<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2586 return value. The type of the return value must be a
2587 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2588
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2589<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2590 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2591 value or a return value with a type that does not match its type, or if it
2592 has a void return type and contains a '<tt>ret</tt>' instruction with a
2593 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2594
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2595<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2596<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2597 the calling function's context. If the caller is a
2598 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2599 instruction after the call. If the caller was an
2600 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2601 the beginning of the "normal" destination block. If the instruction returns
2602 a value, that value shall set the call or invoke instruction's return
2603 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2604
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2605<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2606<pre>
2607 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2608 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2609 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]2610</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2611
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2612</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2613<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2614<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2615
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2616<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2617
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2618<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2619<pre>
2620 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]2621</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2622
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2623<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2624<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2625 different basic block in the current function. There are two forms of this
2626 instruction, corresponding to a conditional branch and an unconditional
2627 branch.</p>
2628
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2629<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2630<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2631 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2632 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2633 target.</p>
2634
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2635<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2636<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2637 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2638 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2639 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2640
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2641<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2642<pre>
2643Test:
2644 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2645 br i1 %cond, label %IfEqual, label %IfUnequal
2646IfEqual:
2647 <a href="#i_ret">ret</a> i32 1
2648IfUnequal:
2649 <a href="#i_ret">ret</a> i32 0
2650</pre>
2651
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2652</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2653
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2654<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2655<div class="doc_subsubsection">
2656 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2657</div>
2658
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2659<div class="doc_text">
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2660
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2661<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2662<pre>
2663 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2664</pre>
2665
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2666<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2667<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]2668 several different places. It is a generalization of the '<tt>br</tt>'
2669 instruction, allowing a branch to occur to one of many possible
2670 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2671
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2672<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2673<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2674 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2675 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2676 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2677
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2678<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2679<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2680 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2681 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2682 transferred to the corresponding destination; otherwise, control flow is
2683 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2684
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2685<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2686<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2687 <tt>switch</tt> instruction, this instruction may be code generated in
2688 different ways. For example, it could be generated as a series of chained
2689 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2690
2691<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2692<pre>
2693 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2694 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2695 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2696
2697 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2698 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2699
2700 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2701 switch i32 %val, label %otherwise [ i32 0, label %onzero
2702 i32 1, label %onone
2703 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2704</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2705
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2706</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2707
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2708
2709<!-- _______________________________________________________________________ -->
2710<div class="doc_subsubsection">
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2711 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2712</div>
2713
2714<div class="doc_text">
2715
2716<h5>Syntax:</h5>
2717<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2718 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]2719</pre>
2720
2721<h5>Overview:</h5>
2722
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2723<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2724 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2725 "<tt>address</tt>". Address must be derived from a <a
2726 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2727
2728<h5>Arguments:</h5>
2729
2730<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2731 rest of the arguments indicate the full set of possible destinations that the
2732 address may point to. Blocks are allowed to occur multiple times in the
2733 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2734
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2735<p>This destination list is required so that dataflow analysis has an accurate
2736 understanding of the CFG.</p>
2737
2738<h5>Semantics:</h5>
2739
2740<p>Control transfers to the block specified in the address argument. All
2741 possible destination blocks must be listed in the label list, otherwise this
2742 instruction has undefined behavior. This implies that jumps to labels
2743 defined in other functions have undefined behavior as well.</p>
2744
2745<h5>Implementation:</h5>
2746
2747<p>This is typically implemented with a jump through a register.</p>
2748
2749<h5>Example:</h5>
2750<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2751 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2752</pre>
2753
2754</div>
2755
2756
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2757<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2758<div class="doc_subsubsection">
2759 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2760</div>
2761
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2762<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2763
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2764<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2765<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2766 &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]2767 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2768</pre>
2769
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2770<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2771<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2772 function, with the possibility of control flow transfer to either the
2773 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2774 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2775 control flow will return to the "normal" label. If the callee (or any
2776 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2777 instruction, control is interrupted and continued at the dynamically nearest
2778 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2779
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2780<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2781<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2782
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2783<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2784 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2785 convention</a> the call should use. If none is specified, the call
2786 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2787
2788 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2789 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2790 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2791
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2792 <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]2793 function value being invoked. In most cases, this is a direct function
2794 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2795 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2796
2797 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2798 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2799
2800 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2801 signature argument types. If the function signature indicates the
2802 function accepts a variable number of arguments, the extra arguments can
2803 be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2804
2805 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2806 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2807
2808 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2809 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2810
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2811 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2812 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2813 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2814</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2815
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2816<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2817<p>This instruction is designed to operate as a standard
2818 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2819 primary difference is that it establishes an association with a label, which
2820 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2821
2822<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2823 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2824 exception. Additionally, this is important for implementation of
2825 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2826
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2827<p>For the purposes of the SSA form, the definition of the value returned by the
2828 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2829 block to the "normal" label. If the callee unwinds then no return value is
2830 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]2831
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]2832<p>Note that the code generator does not yet completely support unwind, and
2833that the invoke/unwind semantics are likely to change in future versions.</p>
2834
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2835<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2836<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2837 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2838 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2839 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2840 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2841</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2842
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2843</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2844
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2845<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2846
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2847<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2848Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2849
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2850<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2851
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2852<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2853<pre>
2854 unwind
2855</pre>
2856
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2857<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2858<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2859 at the first callee in the dynamic call stack which used
2860 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2861 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2862
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2863<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2864<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2865 immediately halt. The dynamic call stack is then searched for the
2866 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2867 Once found, execution continues at the "exceptional" destination block
2868 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2869 instruction in the dynamic call chain, undefined behavior results.</p>
2870
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]2871<p>Note that the code generator does not yet completely support unwind, and
2872that the invoke/unwind semantics are likely to change in future versions.</p>
2873
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2874</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2875
2876<!-- _______________________________________________________________________ -->
2877
2878<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2879Instruction</a> </div>
2880
2881<div class="doc_text">
2882
2883<h5>Syntax:</h5>
2884<pre>
2885 unreachable
2886</pre>
2887
2888<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2889<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2890 instruction is used to inform the optimizer that a particular portion of the
2891 code is not reachable. This can be used to indicate that the code after a
2892 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2893
2894<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2895<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2896
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2897</div>
2898
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2899<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2900<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2901
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2902<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2903
2904<p>Binary operators are used to do most of the computation in a program. They
2905 require two operands of the same type, execute an operation on them, and
2906 produce a single value. The operands might represent multiple data, as is
2907 the case with the <a href="#t_vector">vector</a> data type. The result value
2908 has the same type as its operands.</p>
2909
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2910<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2911
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2912</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2913
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2914<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2915<div class="doc_subsubsection">
2916 <a name="i_add">'<tt>add</tt>' Instruction</a>
2917</div>
2918
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2919<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2920
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2921<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2922<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2923 &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]2924 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2925 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2926 &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]2927</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2928
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2929<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2930<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2931
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2932<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2933<p>The two arguments to the '<tt>add</tt>' instruction must
2934 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2935 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2936
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2937<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2938<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2939
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2940<p>If the sum has unsigned overflow, the result returned is the mathematical
2941 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]2942
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2943<p>Because LLVM integers use a two's complement representation, this instruction
2944 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2945
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2946<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2947 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2948 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2949 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2950
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2951<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2952<pre>
2953 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2954</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2955
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2956</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2957
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2958<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2959<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2960 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2961</div>
2962
2963<div class="doc_text">
2964
2965<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2966<pre>
2967 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2968</pre>
2969
2970<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2971<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2972
2973<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2974<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2975 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2976 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2977
2978<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2979<p>The value produced is the floating point sum of the two operands.</p>
2980
2981<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2982<pre>
2983 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2984</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2985
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2986</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2987
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2988<!-- _______________________________________________________________________ -->
2989<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2990 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2991</div>
2992
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2993<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2994
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2995<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2996<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2997 &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]2998 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2999 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3000 &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]3001</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3002
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3003<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3004<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3005 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3006
3007<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3008 '<tt>neg</tt>' instruction present in most other intermediate
3009 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3010
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3011<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3012<p>The two arguments to the '<tt>sub</tt>' instruction must
3013 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3014 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3015
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3016<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3017<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3018
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3019<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3020 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3021 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3022
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3023<p>Because LLVM integers use a two's complement representation, this instruction
3024 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3025
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3026<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3027 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3028 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
3029 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3030
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3031<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3032<pre>
3033 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3034 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3035</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3036
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3037</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3038
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3039<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3040<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3041 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3042</div>
3043
3044<div class="doc_text">
3045
3046<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3047<pre>
3048 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3049</pre>
3050
3051<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3052<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3053 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3054
3055<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3056 '<tt>fneg</tt>' instruction present in most other intermediate
3057 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3058
3059<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3060<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3061 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3062 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3063
3064<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3065<p>The value produced is the floating point difference of the two operands.</p>
3066
3067<h5>Example:</h5>
3068<pre>
3069 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3070 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3071</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3072
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3073</div>
3074
3075<!-- _______________________________________________________________________ -->
3076<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3077 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3078</div>
3079
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3080<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3081
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3082<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3083<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3084 &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]3085 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3086 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3087 &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]3088</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3089
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3090<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3091<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3092
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3093<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3094<p>The two arguments to the '<tt>mul</tt>' instruction must
3095 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3096 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3097
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3098<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3099<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3100
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3101<p>If the result of the multiplication has unsigned overflow, the result
3102 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3103 width of the result.</p>
3104
3105<p>Because LLVM integers use a two's complement representation, and the result
3106 is the same width as the operands, this instruction returns the correct
3107 result for both signed and unsigned integers. If a full product
3108 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3109 be sign-extended or zero-extended as appropriate to the width of the full
3110 product.</p>
3111
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3112<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3113 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3114 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
3115 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3116
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3117<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3118<pre>
3119 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3120</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3121
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3122</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3123
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3124<!-- _______________________________________________________________________ -->
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3125<div class="doc_subsubsection">
3126 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3127</div>
3128
3129<div class="doc_text">
3130
3131<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3132<pre>
3133 &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]3134</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3135
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3136<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3137<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3138
3139<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3140<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3141 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3142 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3143
3144<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3145<p>The value produced is the floating point product of the two operands.</p>
3146
3147<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3148<pre>
3149 &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]3150</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3151
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3152</div>
3153
3154<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3155<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3156</a></div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3157
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3158<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3159
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3160<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3161<pre>
3162 &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]3163</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3164
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3165<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3166<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3167
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3168<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3169<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3170 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3171 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3172
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3173<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3174<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3175
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3176<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3177 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3178
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3179<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3180
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3181<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3182<pre>
3183 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3184</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3185
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3186</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3187
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3188<!-- _______________________________________________________________________ -->
3189<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3190</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3191
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3192<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3193
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3194<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3195<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3196 &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]3197 &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]3198</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3199
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3200<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3201<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3202
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3203<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3204<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3205 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3206 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3207
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3208<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3209<p>The value produced is the signed integer quotient of the two operands rounded
3210 towards zero.</p>
3211
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3212<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3213 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3214
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3215<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3216 undefined behavior; this is a rare case, but can occur, for example, by doing
3217 a 32-bit division of -2147483648 by -1.</p>
3218
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3219<p>If the <tt>exact</tt> keyword is present, the result value of the
3220 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
3221 would occur.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3222
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3223<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3224<pre>
3225 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3226</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3227
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3228</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3229
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3230<!-- _______________________________________________________________________ -->
3231<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3232Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3233
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3234<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3235
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3236<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3237<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3238 &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]3239</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3240
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3241<h5>Overview:</h5>
3242<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3243
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3244<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3245<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3246 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3247 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3248
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3249<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3250<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3251
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3252<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3253<pre>
3254 &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]3255</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3256
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3257</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3258
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3259<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3260<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3261</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3262
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3263<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3264
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3265<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3266<pre>
3267 &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]3268</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3269
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3270<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3271<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3272 division of its two arguments.</p>
3273
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3274<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3275<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3276 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3277 values. Both arguments must have identical types.</p>
3278
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3279<h5>Semantics:</h5>
3280<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3281 This instruction always performs an unsigned division to get the
3282 remainder.</p>
3283
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3284<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3285 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3286
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3287<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3288
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3289<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3290<pre>
3291 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3292</pre>
3293
3294</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3295
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3296<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3297<div class="doc_subsubsection">
3298 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3299</div>
3300
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3301<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3302
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3303<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3304<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3305 &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]3306</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3307
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3308<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3309<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3310 division of its two operands. This instruction can also take
3311 <a href="#t_vector">vector</a> versions of the values in which case the
3312 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3313
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3314<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3315<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3316 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3317 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3318
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3319<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3320<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3321 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3322 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3323 a value. For more information about the difference,
3324 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3325 Math Forum</a>. For a table of how this is implemented in various languages,
3326 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3327 Wikipedia: modulo operation</a>.</p>
3328
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3329<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3330 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3331
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3332<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3333 Overflow also leads to undefined behavior; this is a rare case, but can
3334 occur, for example, by taking the remainder of a 32-bit division of
3335 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3336 lets srem be implemented using instructions that return both the result of
3337 the division and the remainder.)</p>
3338
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3339<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3340<pre>
3341 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3342</pre>
3343
3344</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3345
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3346<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3347<div class="doc_subsubsection">
3348 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3349
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3350<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3351
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3352<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3353<pre>
3354 &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]3355</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3356
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3357<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3358<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3359 its two operands.</p>
3360
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3361<h5>Arguments:</h5>
3362<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3363 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3364 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3365
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3366<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3367<p>This instruction returns the <i>remainder</i> of a division. The remainder
3368 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3369
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3370<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3371<pre>
3372 &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]3373</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3374
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3375</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3376
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3377<!-- ======================================================================= -->
3378<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3379Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3380
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3381<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3382
3383<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3384 program. They are generally very efficient instructions and can commonly be
3385 strength reduced from other instructions. They require two operands of the
3386 same type, execute an operation on them, and produce a single value. The
3387 resulting value is the same type as its operands.</p>
3388
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3389</div>
3390
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3391<!-- _______________________________________________________________________ -->
3392<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3393Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3394
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3395<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3396
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3397<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3398<pre>
3399 &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]3400</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3401
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3402<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3403<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3404 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3405
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3406<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3407<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3408 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3409 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3410
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3411<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3412<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3413 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3414 is (statically or dynamically) negative or equal to or larger than the number
3415 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3416 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3417 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3418
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3419<h5>Example:</h5>
3420<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3421 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3422 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3423 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3424 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3425 &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]3426</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3427
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3428</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3429
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3430<!-- _______________________________________________________________________ -->
3431<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3432Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3433
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3434<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3435
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3436<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3437<pre>
3438 &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]3439</pre>
3440
3441<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3442<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3443 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3444
3445<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3446<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3447 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3448 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3449
3450<h5>Semantics:</h5>
3451<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3452 significant bits of the result will be filled with zero bits after the shift.
3453 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3454 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3455 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3456 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3457
3458<h5>Example:</h5>
3459<pre>
3460 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3461 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3462 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3463 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3464 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3465 &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]3466</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3467
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3468</div>
3469
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3470<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3471<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3472Instruction</a> </div>
3473<div class="doc_text">
3474
3475<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3476<pre>
3477 &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]3478</pre>
3479
3480<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3481<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3482 operand shifted to the right a specified number of bits with sign
3483 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3484
3485<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3486<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3487 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3488 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3489
3490<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3491<p>This instruction always performs an arithmetic shift right operation, The
3492 most significant bits of the result will be filled with the sign bit
3493 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3494 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3495 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3496 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3497
3498<h5>Example:</h5>
3499<pre>
3500 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3501 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3502 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3503 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3504 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3505 &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]3506</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3507
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3508</div>
3509
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3510<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3511<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3512Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3513
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3514<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3515
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3516<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3517<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3518 &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]3519</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3520
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3521<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3522<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3523 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3524
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3525<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3526<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3527 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3528 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3529
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3530<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3531<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3532
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3533<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3534 <tbody>
3535 <tr>
3536 <td>In0</td>
3537 <td>In1</td>
3538 <td>Out</td>
3539 </tr>
3540 <tr>
3541 <td>0</td>
3542 <td>0</td>
3543 <td>0</td>
3544 </tr>
3545 <tr>
3546 <td>0</td>
3547 <td>1</td>
3548 <td>0</td>
3549 </tr>
3550 <tr>
3551 <td>1</td>
3552 <td>0</td>
3553 <td>0</td>
3554 </tr>
3555 <tr>
3556 <td>1</td>
3557 <td>1</td>
3558 <td>1</td>
3559 </tr>
3560 </tbody>
3561</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3562
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3563<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3564<pre>
3565 &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]3566 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3567 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3568</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3569</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3570<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3571<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3572
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3573<div class="doc_text">
3574
3575<h5>Syntax:</h5>
3576<pre>
3577 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3578</pre>
3579
3580<h5>Overview:</h5>
3581<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3582 two operands.</p>
3583
3584<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3585<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3586 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3587 values. Both arguments must have identical types.</p>
3588
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3589<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3590<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3591
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3592<table border="1" cellspacing="0" cellpadding="4">
3593 <tbody>
3594 <tr>
3595 <td>In0</td>
3596 <td>In1</td>
3597 <td>Out</td>
3598 </tr>
3599 <tr>
3600 <td>0</td>
3601 <td>0</td>
3602 <td>0</td>
3603 </tr>
3604 <tr>
3605 <td>0</td>
3606 <td>1</td>
3607 <td>1</td>
3608 </tr>
3609 <tr>
3610 <td>1</td>
3611 <td>0</td>
3612 <td>1</td>
3613 </tr>
3614 <tr>
3615 <td>1</td>
3616 <td>1</td>
3617 <td>1</td>
3618 </tr>
3619 </tbody>
3620</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3621
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3622<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3623<pre>
3624 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3625 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3626 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3627</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3628
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3629</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3630
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3631<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3632<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3633Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3634
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3635<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3636
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3637<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3638<pre>
3639 &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]3640</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3641
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3642<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3643<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3644 its two operands. The <tt>xor</tt> is used to implement the "one's
3645 complement" operation, which is the "~" operator in C.</p>
3646
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3647<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3648<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3649 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3650 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3651
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3652<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3653<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3654
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3655<table border="1" cellspacing="0" cellpadding="4">
3656 <tbody>
3657 <tr>
3658 <td>In0</td>
3659 <td>In1</td>
3660 <td>Out</td>
3661 </tr>
3662 <tr>
3663 <td>0</td>
3664 <td>0</td>
3665 <td>0</td>
3666 </tr>
3667 <tr>
3668 <td>0</td>
3669 <td>1</td>
3670 <td>1</td>
3671 </tr>
3672 <tr>
3673 <td>1</td>
3674 <td>0</td>
3675 <td>1</td>
3676 </tr>
3677 <tr>
3678 <td>1</td>
3679 <td>1</td>
3680 <td>0</td>
3681 </tr>
3682 </tbody>
3683</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3684
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3685<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3686<pre>
3687 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3688 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3689 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3690 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3691</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3692
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3693</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3694
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3695<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3696<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3697 <a name="vectorops">Vector Operations</a>
3698</div>
3699
3700<div class="doc_text">
3701
3702<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3703 target-independent manner. These instructions cover the element-access and
3704 vector-specific operations needed to process vectors effectively. While LLVM
3705 does directly support these vector operations, many sophisticated algorithms
3706 will want to use target-specific intrinsics to take full advantage of a
3707 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3708
3709</div>
3710
3711<!-- _______________________________________________________________________ -->
3712<div class="doc_subsubsection">
3713 <a name="i_extractelement">'<tt>extractelement</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>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3720 &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]3721</pre>
3722
3723<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3724<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3725 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3726
3727
3728<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3729<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3730 of <a href="#t_vector">vector</a> type. The second operand is an index
3731 indicating the position from which to extract the element. The index may be
3732 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 scalar of the same type as the element type of
3736 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3737 <tt>val</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; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3743</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3744
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3745</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3746
3747<!-- _______________________________________________________________________ -->
3748<div class="doc_subsubsection">
3749 <a name="i_insertelement">'<tt>insertelement</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>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3756 &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]3757</pre>
3758
3759<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3760<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3761 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3762
3763<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3764<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3765 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3766 whose type must equal the element type of the first operand. The third
3767 operand is an index indicating the position at which to insert the value.
3768 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3769
3770<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3771<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3772 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3773 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3774 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3775
3776<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3777<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3778 &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]3779</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3780
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3781</div>
3782
3783<!-- _______________________________________________________________________ -->
3784<div class="doc_subsubsection">
3785 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3786</div>
3787
3788<div class="doc_text">
3789
3790<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3791<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3792 &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]3793</pre>
3794
3795<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3796<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3797 from two input vectors, returning a vector with the same element type as the
3798 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3799
3800<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3801<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3802 with types that match each other. The third argument is a shuffle mask whose
3803 element type is always 'i32'. The result of the instruction is a vector
3804 whose length is the same as the shuffle mask and whose element type is the
3805 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3806
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3807<p>The shuffle mask operand is required to be a constant vector with either
3808 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3809
3810<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3811<p>The elements of the two input vectors are numbered from left to right across
3812 both of the vectors. The shuffle mask operand specifies, for each element of
3813 the result vector, which element of the two input vectors the result element
3814 gets. The element selector may be undef (meaning "don't care") and the
3815 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3816
3817<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3818<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3819 &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]3820 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3821 &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]3822 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3823 &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]3824 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3825 &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]3826 &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]3827</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3828
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3829</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3830
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3831<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3832<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3833 <a name="aggregateops">Aggregate Operations</a>
3834</div>
3835
3836<div class="doc_text">
3837
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3838<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3839
3840</div>
3841
3842<!-- _______________________________________________________________________ -->
3843<div class="doc_subsubsection">
3844 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3845</div>
3846
3847<div class="doc_text">
3848
3849<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3850<pre>
3851 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3852</pre>
3853
3854<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3855<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3856 or array element from an aggregate value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3857
3858<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3859<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3860 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3861 operands are constant indices to specify which value to extract in a similar
3862 manner as indices in a
3863 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3864
3865<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3866<p>The result is the value at the position in the aggregate specified by the
3867 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3868
3869<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3870<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3871 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3872</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3873
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3874</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3875
3876<!-- _______________________________________________________________________ -->
3877<div class="doc_subsubsection">
3878 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3879</div>
3880
3881<div class="doc_text">
3882
3883<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3884<pre>
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]3885 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt; <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3886</pre>
3887
3888<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3889<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3890 array element in an aggregate.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3891
3892
3893<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3894<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3895 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3896 second operand is a first-class value to insert. The following operands are
3897 constant indices indicating the position at which to insert the value in a
3898 similar manner as indices in a
3899 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3900 value to insert must have the same type as the value identified by the
3901 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3902
3903<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3904<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3905 that of <tt>val</tt> except that the value at the position specified by the
3906 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3907
3908<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3909<pre>
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]3910 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
3911 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3912</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3913
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3914</div>
3915
3916
3917<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3918<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3919 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3920</div>
3921
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3922<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3923
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3924<p>A key design point of an SSA-based representation is how it represents
3925 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]3926 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3927 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3928
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3929</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3930
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3931<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3932<div class="doc_subsubsection">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3933 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3934</div>
3935
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3936<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3937
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3938<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3939<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3940 &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]3941</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3942
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3943<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3944<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3945 currently executing function, to be automatically released when this function
3946 returns to its caller. The object is always allocated in the generic address
3947 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3948
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3949<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3950<p>The '<tt>alloca</tt>' instruction
3951 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3952 runtime stack, returning a pointer of the appropriate type to the program.
3953 If "NumElements" is specified, it is the number of elements allocated,
3954 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3955 specified, the value result of the allocation is guaranteed to be aligned to
3956 at least that boundary. If not specified, or if zero, the target can choose
3957 to align the allocation on any convenient boundary compatible with the
3958 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3959
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3960<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3961
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3962<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]3963<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3964 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3965 memory is automatically released when the function returns. The
3966 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3967 variables that must have an address available. When the function returns
3968 (either with the <tt><a href="#i_ret">ret</a></tt>
3969 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3970 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3971
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3972<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3973<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3974 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3975 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3976 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3977 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3978</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3979
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3980</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3981
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3982<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3983<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3984Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3985
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3986<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3987
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3988<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3989<pre>
3990 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3991 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3992</pre>
3993
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3994<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3995<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3996
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3997<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3998<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3999 from which to load. The pointer must point to
4000 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4001 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
4002 number or order of execution of this <tt>load</tt> with other
4003 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4004 instructions. </p>
4005
4006<p>The optional constant "align" argument specifies the alignment of the
4007 operation (that is, the alignment of the memory address). A value of 0 or an
4008 omitted "align" argument means that the operation has the preferential
4009 alignment for the target. It is the responsibility of the code emitter to
4010 ensure that the alignment information is correct. Overestimating the
4011 alignment results in an undefined behavior. Underestimating the alignment may
4012 produce less efficient code. An alignment of 1 is always safe.</p>
4013
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4014<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4015<p>The location of memory pointed to is loaded. If the value being loaded is of
4016 scalar type then the number of bytes read does not exceed the minimum number
4017 of bytes needed to hold all bits of the type. For example, loading an
4018 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4019 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4020 is undefined if the value was not originally written using a store of the
4021 same type.</p>
4022
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4023<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4024<pre>
4025 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4026 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4027 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4028</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4029
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4030</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4031
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4032<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4033<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4034Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4035
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]4036<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4037
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4038<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4039<pre>
4040 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]4041 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]4042</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4043
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4044<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4045<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4046
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4047<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4048<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4049 and an address at which to store it. The type of the
4050 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4051 the <a href="#t_firstclass">first class</a> type of the
4052 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
4053 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
4054 or order of execution of this <tt>store</tt> with other
4055 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4056 instructions.</p>
4057
4058<p>The optional constant "align" argument specifies the alignment of the
4059 operation (that is, the alignment of the memory address). A value of 0 or an
4060 omitted "align" argument means that the operation has the preferential
4061 alignment for the target. It is the responsibility of the code emitter to
4062 ensure that the alignment information is correct. Overestimating the
4063 alignment results in an undefined behavior. Underestimating the alignment may
4064 produce less efficient code. An alignment of 1 is always safe.</p>
4065
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4066<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4067<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4068 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4069 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4070 does not exceed the minimum number of bytes needed to hold all bits of the
4071 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4072 writing a value of a type like <tt>i20</tt> with a size that is not an
4073 integral number of bytes, it is unspecified what happens to the extra bits
4074 that do not belong to the type, but they will typically be overwritten.</p>
4075
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4076<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4077<pre>
4078 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4079 store i32 3, i32* %ptr <i>; yields {void}</i>
4080 %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]4081</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4082
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4083</div>
4084
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4085<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4086<div class="doc_subsubsection">
4087 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4088</div>
4089
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4090<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4091
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4092<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4093<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4094 &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]4095 &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]4096</pre>
4097
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4098<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4099<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
4100 subelement of an aggregate data structure. It performs address calculation
4101 only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4102
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4103<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4104<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4105 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4106 elements of the aggregate object are indexed. The interpretation of each
4107 index is dependent on the type being indexed into. The first index always
4108 indexes the pointer value given as the first argument, the second index
4109 indexes a value of the type pointed to (not necessarily the value directly
4110 pointed to, since the first index can be non-zero), etc. The first type
4111 indexed into must be a pointer value, subsequent types can be arrays, vectors
4112 and structs. Note that subsequent types being indexed into can never be
4113 pointers, since that would require loading the pointer before continuing
4114 calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4115
4116<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]4117 When indexing into a (optionally packed) structure, only <tt>i32</tt> integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4118 <b>constants</b> are allowed. When indexing into an array, pointer or
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4119 vector, integers of any width are allowed, and they are not required to be
4120 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4121
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4122<p>For example, let's consider a C code fragment and how it gets compiled to
4123 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4124
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4125<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4126<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4127struct RT {
4128 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4129 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4130 char C;
4131};
4132struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4133 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4134 double Y;
4135 struct RT Z;
4136};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4137
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4138int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4139 return &amp;s[1].Z.B[5][13];
4140}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4141</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4142</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4143
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4144<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4145
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4146<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4147<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4148%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4149%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4150
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4151define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4152entry:
4153 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4154 ret i32* %reg
4155}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4156</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4157</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4158
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4159<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4160<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]4161 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4162 }</tt>' type, a structure. The second index indexes into the third element
4163 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4164 i8 }</tt>' type, another structure. The third index indexes into the second
4165 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4166 array. The two dimensions of the array are subscripted into, yielding an
4167 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4168 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4169
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4170<p>Note that it is perfectly legal to index partially through a structure,
4171 returning a pointer to an inner element. Because of this, the LLVM code for
4172 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4173
4174<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4175 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4176 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4177 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4178 %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]4179 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4180 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4181 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4182 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4183</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4184
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4185<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4186 <tt>getelementptr</tt> is undefined if the base pointer is not an
4187 <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]4188 that would be formed by successive addition of the offsets implied by the
4189 indices to the base address with infinitely precise arithmetic are not an
4190 <i>in bounds</i> address of that allocated object.
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4191 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame]4192 that point into the object, plus the address one byte past the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4193
4194<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4195 the base address with silently-wrapping two's complement arithmetic, and
4196 the result value of the <tt>getelementptr</tt> may be outside the object
4197 pointed to by the base pointer. The result value may not necessarily be
4198 used to access memory though, even if it happens to point into allocated
4199 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4200 section for more information.</p>
4201
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4202<p>The getelementptr instruction is often confusing. For some more insight into
4203 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4204
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4205<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4206<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4207 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4208 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4209 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4210 %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]4211 <i>; yields i8*:eptr</i>
4212 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4213 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4214 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4215</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4216
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4217</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4218
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4219<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4220<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4221</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4222
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4223<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4224
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4225<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4226 which all take a single operand and a type. They perform various bit
4227 conversions on the operand.</p>
4228
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4229</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4230
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4231<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4232<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4233 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4234</div>
4235<div class="doc_text">
4236
4237<h5>Syntax:</h5>
4238<pre>
4239 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4240</pre>
4241
4242<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4243<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4244 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4245
4246<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4247<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4248 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4249 size and type of the result, which must be
4250 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4251 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4252 allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4253
4254<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4255<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4256 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4257 source size must be larger than the destination size, <tt>trunc</tt> cannot
4258 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4259
4260<h5>Example:</h5>
4261<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4262 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4263 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4264 %Z = trunc i32 122 to i1 <i>; yields i1:false</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_zext">'<tt>zext .. to</tt>' Instruction</a>
4272</div>
4273<div class="doc_text">
4274
4275<h5>Syntax:</h5>
4276<pre>
4277 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4278</pre>
4279
4280<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4281<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4282 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4283
4284
4285<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4286<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]4287 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4288 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4289 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4290 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4291
4292<h5>Semantics:</h5>
4293<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]4294 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4295
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4296<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]4297
4298<h5>Example:</h5>
4299<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4300 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4301 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4302</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4303
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4304</div>
4305
4306<!-- _______________________________________________________________________ -->
4307<div class="doc_subsubsection">
4308 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4309</div>
4310<div class="doc_text">
4311
4312<h5>Syntax:</h5>
4313<pre>
4314 &lt;result&gt; = sext &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>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4319
4320<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4321<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4322 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4323 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4324 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4325 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4326
4327<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4328<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4329 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4330 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4331
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4332<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]4333
4334<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4335<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4336 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4337 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4338</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4339
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4340</div>
4341
4342<!-- _______________________________________________________________________ -->
4343<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4344 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4345</div>
4346
4347<div class="doc_text">
4348
4349<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4350<pre>
4351 &lt;result&gt; = fptrunc &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>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4356 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4357
4358<h5>Arguments:</h5>
4359<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4360 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4361 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4362 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4363 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4364
4365<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4366<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4367 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4368 <a href="#t_floating">floating point</a> type. If the value cannot fit
4369 within the destination type, <tt>ty2</tt>, then the results are
4370 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4371
4372<h5>Example:</h5>
4373<pre>
4374 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4375 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4376</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4377
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4378</div>
4379
4380<!-- _______________________________________________________________________ -->
4381<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4382 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4383</div>
4384<div class="doc_text">
4385
4386<h5>Syntax:</h5>
4387<pre>
4388 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4389</pre>
4390
4391<h5>Overview:</h5>
4392<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]4393 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4394
4395<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4396<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4397 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4398 a <a href="#t_floating">floating point</a> type to cast it to. The source
4399 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4400
4401<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4402<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4403 <a href="#t_floating">floating point</a> type to a larger
4404 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4405 used to make a <i>no-op cast</i> because it always changes bits. Use
4406 <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]4407
4408<h5>Example:</h5>
4409<pre>
4410 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4411 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
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 Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4418 <a name="i_fptoui">'<tt>fptoui .. 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 Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4424 &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]4425</pre>
4426
4427<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4428<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4429 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4430
4431<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4432<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4433 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4434 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4435 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4436 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4437
4438<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4439<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4440 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4441 towards zero) unsigned integer value. If the value cannot fit
4442 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4443
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4444<h5>Example:</h5>
4445<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4446 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4447 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4448 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4449</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4450
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4451</div>
4452
4453<!-- _______________________________________________________________________ -->
4454<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4455 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4456</div>
4457<div class="doc_text">
4458
4459<h5>Syntax:</h5>
4460<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4461 &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]4462</pre>
4463
4464<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4465<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4466 <a href="#t_floating">floating point</a> <tt>value</tt> to
4467 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4468
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4469<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4470<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4471 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4472 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4473 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4474 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4475
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4476<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4477<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4478 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4479 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4480 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4481
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4482<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4483<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4484 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4485 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4486 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4487</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4488
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4489</div>
4490
4491<!-- _______________________________________________________________________ -->
4492<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4493 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4494</div>
4495<div class="doc_text">
4496
4497<h5>Syntax:</h5>
4498<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4499 &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]4500</pre>
4501
4502<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4503<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4504 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4505
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4506<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4507<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]4508 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4509 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4510 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4511 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4512
4513<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4514<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4515 integer quantity and converts it to the corresponding floating point
4516 value. If the value cannot fit in the floating point value, the results are
4517 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4518
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4519<h5>Example:</h5>
4520<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4521 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4522 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4523</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4524
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4525</div>
4526
4527<!-- _______________________________________________________________________ -->
4528<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4529 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4530</div>
4531<div class="doc_text">
4532
4533<h5>Syntax:</h5>
4534<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4535 &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]4536</pre>
4537
4538<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4539<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4540 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4541
4542<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4543<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]4544 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4545 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4546 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4547 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4548
4549<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4550<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4551 quantity and converts it to the corresponding floating point value. If the
4552 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4553
4554<h5>Example:</h5>
4555<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4556 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4557 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4558</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4559
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4560</div>
4561
4562<!-- _______________________________________________________________________ -->
4563<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4564 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4565</div>
4566<div class="doc_text">
4567
4568<h5>Syntax:</h5>
4569<pre>
4570 &lt;result&gt; = ptrtoint &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>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4575 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4576
4577<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4578<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4579 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4580 <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]4581
4582<h5>Semantics:</h5>
4583<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4584 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4585 truncating or zero extending that value to the size of the integer type. If
4586 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4587 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4588 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4589 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4590
4591<h5>Example:</h5>
4592<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4593 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4594 %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]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">
4601 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4602</div>
4603<div class="doc_text">
4604
4605<h5>Syntax:</h5>
4606<pre>
4607 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4608</pre>
4609
4610<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4611<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4612 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4613
4614<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4615<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4616 value to cast, and a type to cast it to, which must be a
4617 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4618
4619<h5>Semantics:</h5>
4620<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4621 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4622 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4623 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4624 than the size of a pointer then a zero extension is done. If they are the
4625 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4626
4627<h5>Example:</h5>
4628<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4629 %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]4630 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4631 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4632</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4633
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4634</div>
4635
4636<!-- _______________________________________________________________________ -->
4637<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4638 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4639</div>
4640<div class="doc_text">
4641
4642<h5>Syntax:</h5>
4643<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4644 &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]4645</pre>
4646
4647<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4648<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4649 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4650
4651<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4652<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4653 non-aggregate first class value, and a type to cast it to, which must also be
4654 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4655 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4656 identical. If the source type is a pointer, the destination type must also be
4657 a pointer. This instruction supports bitwise conversion of vectors to
4658 integers and to vectors of other types (as long as they have the same
4659 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4660
4661<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4662<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4663 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4664 this conversion. The conversion is done as if the <tt>value</tt> had been
4665 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4666 be converted to other pointer types with this instruction. To convert
4667 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4668 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4669
4670<h5>Example:</h5>
4671<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4672 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4673 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4674 %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]4675</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4676
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4677</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4678
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4679<!-- ======================================================================= -->
4680<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4681
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4682<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4683
4684<p>The instructions in this category are the "miscellaneous" instructions, which
4685 defy better classification.</p>
4686
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4687</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4688
4689<!-- _______________________________________________________________________ -->
4690<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4691</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4692
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4693<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4694
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4695<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4696<pre>
4697 &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]4698</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4699
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4700<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4701<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4702 boolean values based on comparison of its two integer, integer vector, or
4703 pointer operands.</p>
4704
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4705<h5>Arguments:</h5>
4706<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4707 the condition code indicating the kind of comparison to perform. It is not a
4708 value, just a keyword. The possible condition code are:</p>
4709
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4710<ol>
4711 <li><tt>eq</tt>: equal</li>
4712 <li><tt>ne</tt>: not equal </li>
4713 <li><tt>ugt</tt>: unsigned greater than</li>
4714 <li><tt>uge</tt>: unsigned greater or equal</li>
4715 <li><tt>ult</tt>: unsigned less than</li>
4716 <li><tt>ule</tt>: unsigned less or equal</li>
4717 <li><tt>sgt</tt>: signed greater than</li>
4718 <li><tt>sge</tt>: signed greater or equal</li>
4719 <li><tt>slt</tt>: signed less than</li>
4720 <li><tt>sle</tt>: signed less or equal</li>
4721</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4722
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4723<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4724 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4725 typed. They must also be identical types.</p>
4726
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4727<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4728<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4729 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4730 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]4731 result, as follows:</p>
4732
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4733<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4734 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4735 <tt>false</tt> otherwise. No sign interpretation is necessary or
4736 performed.</li>
4737
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4738 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4739 <tt>false</tt> otherwise. No sign interpretation is necessary or
4740 performed.</li>
4741
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4742 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4743 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4744
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4745 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4746 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4747 to <tt>op2</tt>.</li>
4748
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4749 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4750 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4751
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4752 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4753 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4754
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4755 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4756 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4757
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4758 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4759 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4760 to <tt>op2</tt>.</li>
4761
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4762 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4763 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4764
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4765 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4766 <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]4767</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4768
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4769<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4770 values are compared as if they were integers.</p>
4771
4772<p>If the operands are integer vectors, then they are compared element by
4773 element. The result is an <tt>i1</tt> vector with the same number of elements
4774 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4775
4776<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4777<pre>
4778 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4779 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4780 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4781 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4782 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4783 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4784</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4785
4786<p>Note that the code generator does not yet support vector types with
4787 the <tt>icmp</tt> instruction.</p>
4788
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4789</div>
4790
4791<!-- _______________________________________________________________________ -->
4792<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4793</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4794
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4795<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4796
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4797<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4798<pre>
4799 &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]4800</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4801
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4802<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4803<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4804 values based on comparison of its operands.</p>
4805
4806<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]4807(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4808
4809<p>If the operands are floating point vectors, then the result type is a vector
4810 of boolean with the same number of elements as the operands being
4811 compared.</p>
4812
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4813<h5>Arguments:</h5>
4814<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4815 the condition code indicating the kind of comparison to perform. It is not a
4816 value, just a keyword. The possible condition code are:</p>
4817
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4818<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4819 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4820 <li><tt>oeq</tt>: ordered and equal</li>
4821 <li><tt>ogt</tt>: ordered and greater than </li>
4822 <li><tt>oge</tt>: ordered and greater than or equal</li>
4823 <li><tt>olt</tt>: ordered and less than </li>
4824 <li><tt>ole</tt>: ordered and less than or equal</li>
4825 <li><tt>one</tt>: ordered and not equal</li>
4826 <li><tt>ord</tt>: ordered (no nans)</li>
4827 <li><tt>ueq</tt>: unordered or equal</li>
4828 <li><tt>ugt</tt>: unordered or greater than </li>
4829 <li><tt>uge</tt>: unordered or greater than or equal</li>
4830 <li><tt>ult</tt>: unordered or less than </li>
4831 <li><tt>ule</tt>: unordered or less than or equal</li>
4832 <li><tt>une</tt>: unordered or not equal</li>
4833 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4834 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4835</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4836
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4837<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4838 <i>unordered</i> means that either operand may be a QNAN.</p>
4839
4840<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4841 a <a href="#t_floating">floating point</a> type or
4842 a <a href="#t_vector">vector</a> of floating point type. They must have
4843 identical types.</p>
4844
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4845<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4846<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4847 according to the condition code given as <tt>cond</tt>. If the operands are
4848 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4849 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4850 follows:</p>
4851
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4852<ol>
4853 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4854
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4855 <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]4856 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4857
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4858 <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]4859 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4860
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4861 <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]4862 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4863
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4864 <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]4865 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4866
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4867 <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]4868 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4869
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4870 <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]4871 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4872
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4873 <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]4874
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4875 <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]4876 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4877
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4878 <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]4879 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4880
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4881 <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]4882 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4883
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4884 <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]4885 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4886
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4887 <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]4888 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4889
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4890 <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]4891 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4892
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4893 <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]4894
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4895 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4896</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4897
4898<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4899<pre>
4900 &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]4901 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4902 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4903 &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]4904</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4905
4906<p>Note that the code generator does not yet support vector types with
4907 the <tt>fcmp</tt> instruction.</p>
4908
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4909</div>
4910
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4911<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4912<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4913 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4914</div>
4915
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4916<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4917
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4918<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4919<pre>
4920 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4921</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4922
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4923<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4924<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4925 SSA graph representing the function.</p>
4926
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4927<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4928<p>The type of the incoming values is specified with the first type field. After
4929 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4930 one pair for each predecessor basic block of the current block. Only values
4931 of <a href="#t_firstclass">first class</a> type may be used as the value
4932 arguments to the PHI node. Only labels may be used as the label
4933 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4934
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4935<p>There must be no non-phi instructions between the start of a basic block and
4936 the PHI instructions: i.e. PHI instructions must be first in a basic
4937 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4938
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4939<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4940 occur on the edge from the corresponding predecessor block to the current
4941 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4942 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]4943
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4944<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4945<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4946 specified by the pair corresponding to the predecessor basic block that
4947 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4948
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4949<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4950<pre>
4951Loop: ; Infinite loop that counts from 0 on up...
4952 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4953 %nextindvar = add i32 %indvar, 1
4954 br label %Loop
4955</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4956
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4957</div>
4958
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4959<!-- _______________________________________________________________________ -->
4960<div class="doc_subsubsection">
4961 <a name="i_select">'<tt>select</tt>' Instruction</a>
4962</div>
4963
4964<div class="doc_text">
4965
4966<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4967<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4968 &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>
4969
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4970 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4971</pre>
4972
4973<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4974<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4975 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4976
4977
4978<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4979<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4980 values indicating the condition, and two values of the
4981 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4982 vectors and the condition is a scalar, then entire vectors are selected, not
4983 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4984
4985<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4986<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4987 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4988
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4989<p>If the condition is a vector of i1, then the value arguments must be vectors
4990 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4991
4992<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4993<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4994 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4995</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4996
4997<p>Note that the code generator does not yet support conditions
4998 with vector type.</p>
4999
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5000</div>
5001
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5002<!-- _______________________________________________________________________ -->
5003<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5004 <a name="i_call">'<tt>call</tt>' Instruction</a>
5005</div>
5006
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5007<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5008
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5009<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5010<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5011 &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]5012</pre>
5013
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5014<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5015<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5016
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5017<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5018<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5019
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5020<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5021 <li>The optional "tail" marker indicates that the callee function does not
5022 access any allocas or varargs in the caller. Note that calls may be
5023 marked "tail" even if they do not occur before
5024 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5025 present, the function call is eligible for tail call optimization,
5026 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
5027 optimized into a jump</a>. As of this writing, the extra requirements for
5028 a call to actually be optimized are:
5029 <ul>
5030 <li>Caller and callee both have the calling
5031 convention <tt>fastcc</tt>.</li>
5032 <li>The call is in tail position (ret immediately follows call and ret
5033 uses value of call or is void).</li>
5034 <li>Option <tt>-tailcallopt</tt> is enabled,
5035 or <code>llvm::PerformTailCallOpt</code> is <code>true</code>.</li>
5036 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5037 constraints are met.</a></li>
5038 </ul>
5039 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5040
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5041 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5042 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5043 defaults to using C calling conventions. The calling convention of the
5044 call must match the calling convention of the target function, or else the
5045 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5046
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5047 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5048 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5049 '<tt>inreg</tt>' attributes are valid here.</li>
5050
5051 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5052 type of the return value. Functions that return no value are marked
5053 <tt><a href="#t_void">void</a></tt>.</li>
5054
5055 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5056 being invoked. The argument types must match the types implied by this
5057 signature. This type can be omitted if the function is not varargs and if
5058 the function type does not return a pointer to a function.</li>
5059
5060 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5061 be invoked. In most cases, this is a direct function invocation, but
5062 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5063 to function value.</li>
5064
5065 <li>'<tt>function args</tt>': argument list whose types match the function
5066 signature argument types. All arguments must be of
5067 <a href="#t_firstclass">first class</a> type. If the function signature
5068 indicates the function accepts a variable number of arguments, the extra
5069 arguments can be specified.</li>
5070
5071 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5072 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5073 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5074</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5075
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5076<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5077<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5078 a specified function, with its incoming arguments bound to the specified
5079 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5080 function, control flow continues with the instruction after the function
5081 call, and the return value of the function is bound to the result
5082 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5083
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5084<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5085<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5086 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5087 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5088 %X = tail call i32 @foo() <i>; yields i32</i>
5089 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5090 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5091
5092 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5093 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5094 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5095 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5096 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5097 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5098</pre>
5099
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5100<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5101standard C99 library as being the C99 library functions, and may perform
5102optimizations or generate code for them under that assumption. This is
5103something we'd like to change in the future to provide better support for
5104freestanding environments and non-C-based langauges.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5105
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5106</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5107
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5108<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5109<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5110 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5111</div>
5112
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5113<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5114
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5115<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5116<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5117 &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]5118</pre>
5119
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5120<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5121<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5122 the "variable argument" area of a function call. It is used to implement the
5123 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5124
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5125<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5126<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5127 argument. It returns a value of the specified argument type and increments
5128 the <tt>va_list</tt> to point to the next argument. The actual type
5129 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5130
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5131<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5132<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5133 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5134 to the next argument. For more information, see the variable argument
5135 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5136
5137<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]5138 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5139 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5140
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5141<p><tt>va_arg</tt> is an LLVM instruction instead of
5142 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5143 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5144
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5145<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5146<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5147
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5148<p>Note that the code generator does not yet fully support va_arg on many
5149 targets. Also, it does not currently support va_arg with aggregate types on
5150 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5151
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5152</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5153
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5154<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5155<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5156<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5157
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5158<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5159
5160<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5161 well known names and semantics and are required to follow certain
5162 restrictions. Overall, these intrinsics represent an extension mechanism for
5163 the LLVM language that does not require changing all of the transformations
5164 in LLVM when adding to the language (or the bitcode reader/writer, the
5165 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5166
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5167<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5168 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5169 begin with this prefix. Intrinsic functions must always be external
5170 functions: you cannot define the body of intrinsic functions. Intrinsic
5171 functions may only be used in call or invoke instructions: it is illegal to
5172 take the address of an intrinsic function. Additionally, because intrinsic
5173 functions are part of the LLVM language, it is required if any are added that
5174 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5175
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5176<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5177 family of functions that perform the same operation but on different data
5178 types. Because LLVM can represent over 8 million different integer types,
5179 overloading is used commonly to allow an intrinsic function to operate on any
5180 integer type. One or more of the argument types or the result type can be
5181 overloaded to accept any integer type. Argument types may also be defined as
5182 exactly matching a previous argument's type or the result type. This allows
5183 an intrinsic function which accepts multiple arguments, but needs all of them
5184 to be of the same type, to only be overloaded with respect to a single
5185 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5186
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5187<p>Overloaded intrinsics will have the names of its overloaded argument types
5188 encoded into its function name, each preceded by a period. Only those types
5189 which are overloaded result in a name suffix. Arguments whose type is matched
5190 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5191 can take an integer of any width and returns an integer of exactly the same
5192 integer width. This leads to a family of functions such as
5193 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5194 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5195 suffix is required. Because the argument's type is matched against the return
5196 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5197
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5198<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5199 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5200
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5201</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5202
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5203<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5204<div class="doc_subsection">
5205 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5206</div>
5207
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5208<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5209
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5210<p>Variable argument support is defined in LLVM with
5211 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5212 intrinsic functions. These functions are related to the similarly named
5213 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5214
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5215<p>All of these functions operate on arguments that use a target-specific value
5216 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5217 not define what this type is, so all transformations should be prepared to
5218 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5219
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5220<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]5221 instruction and the variable argument handling intrinsic functions are
5222 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5223
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5224<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5225<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5226define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5227 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5228 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5229 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5230 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5231
5232 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5233 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5234
5235 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5236 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5237 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5238 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5239 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5240
5241 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5242 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5243 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5244}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5245
5246declare void @llvm.va_start(i8*)
5247declare void @llvm.va_copy(i8*, i8*)
5248declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5249</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5250</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5251
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5252</div>
5253
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5254<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5255<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5256 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5257</div>
5258
5259
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5260<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5261
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5262<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5263<pre>
5264 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5265</pre>
5266
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5267<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5268<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5269 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]5270
5271<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5272<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]5273
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5274<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5275<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]5276 macro available in C. In a target-dependent way, it initializes
5277 the <tt>va_list</tt> element to which the argument points, so that the next
5278 call to <tt>va_arg</tt> will produce the first variable argument passed to
5279 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5280 need to know the last argument of the function as the compiler can figure
5281 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5282
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5283</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5284
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5285<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5286<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5287 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5288</div>
5289
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5290<div class="doc_text">
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5291
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5292<h5>Syntax:</h5>
5293<pre>
5294 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5295</pre>
5296
5297<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5298<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5299 which has been initialized previously
5300 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5301 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5302
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5303<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5304<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]5305
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5306<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5307<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]5308 macro available in C. In a target-dependent way, it destroys
5309 the <tt>va_list</tt> element to which the argument points. Calls
5310 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5311 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5312 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5313
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5314</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5315
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5316<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5317<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5318 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5319</div>
5320
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5321<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5322
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5323<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5324<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5325 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5326</pre>
5327
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5328<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5329<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5330 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5331
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5332<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5333<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]5334 The second argument is a pointer to a <tt>va_list</tt> element to copy
5335 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5336
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5337<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5338<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]5339 macro available in C. In a target-dependent way, it copies the
5340 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5341 element. This intrinsic is necessary because
5342 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5343 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5344
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5345</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5346
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5347<!-- ======================================================================= -->
5348<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5349 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5350</div>
5351
5352<div class="doc_text">
5353
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5354<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5355Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5356intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5357roots on the stack</a>, as well as garbage collector implementations that
5358require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5359barriers. Front-ends for type-safe garbage collected languages should generate
5360these intrinsics to make use of the LLVM garbage collectors. For more details,
5361see <a href="GarbageCollection.html">Accurate Garbage Collection with
5362LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5363
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5364<p>The garbage collection intrinsics only operate on objects in the generic
5365 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5366
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5367</div>
5368
5369<!-- _______________________________________________________________________ -->
5370<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5371 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5372</div>
5373
5374<div class="doc_text">
5375
5376<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5377<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5378 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5379</pre>
5380
5381<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5382<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]5383 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5384
5385<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5386<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5387 root pointer. The second pointer (which must be either a constant or a
5388 global value address) contains the meta-data to be associated with the
5389 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5390
5391<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5392<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]5393 location. At compile-time, the code generator generates information to allow
5394 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5395 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5396 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5397
5398</div>
5399
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5400<!-- _______________________________________________________________________ -->
5401<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5402 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5403</div>
5404
5405<div class="doc_text">
5406
5407<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5408<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5409 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5410</pre>
5411
5412<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5413<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5414 locations, allowing garbage collector implementations that require read
5415 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5416
5417<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5418<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]5419 allocated from the garbage collector. The first object is a pointer to the
5420 start of the referenced object, if needed by the language runtime (otherwise
5421 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5422
5423<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5424<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5425 instruction, but may be replaced with substantially more complex code by the
5426 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5427 may only be used in a function which <a href="#gc">specifies a GC
5428 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5429
5430</div>
5431
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5432<!-- _______________________________________________________________________ -->
5433<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5434 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5435</div>
5436
5437<div class="doc_text">
5438
5439<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5440<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5441 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5442</pre>
5443
5444<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5445<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5446 locations, allowing garbage collector implementations that require write
5447 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5448
5449<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5450<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]5451 object to store it to, and the third is the address of the field of Obj to
5452 store to. If the runtime does not require a pointer to the object, Obj may
5453 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5454
5455<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5456<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5457 instruction, but may be replaced with substantially more complex code by the
5458 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5459 may only be used in a function which <a href="#gc">specifies a GC
5460 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5461
5462</div>
5463
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5464<!-- ======================================================================= -->
5465<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5466 <a name="int_codegen">Code Generator Intrinsics</a>
5467</div>
5468
5469<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5470
5471<p>These intrinsics are provided by LLVM to expose special features that may
5472 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5473
5474</div>
5475
5476<!-- _______________________________________________________________________ -->
5477<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5478 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5479</div>
5480
5481<div class="doc_text">
5482
5483<h5>Syntax:</h5>
5484<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5485 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5486</pre>
5487
5488<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5489<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5490 target-specific value indicating the return address of the current function
5491 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5492
5493<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5494<p>The argument to this intrinsic indicates which function to return the address
5495 for. Zero indicates the calling function, one indicates its caller, etc.
5496 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5497
5498<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5499<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5500 indicating the return address of the specified call frame, or zero if it
5501 cannot be identified. The value returned by this intrinsic is likely to be
5502 incorrect or 0 for arguments other than zero, so it should only be used for
5503 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5504
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5505<p>Note that calling this intrinsic does not prevent function inlining or other
5506 aggressive transformations, so the value returned may not be that of the
5507 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5508
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5509</div>
5510
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5511<!-- _______________________________________________________________________ -->
5512<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5513 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5514</div>
5515
5516<div class="doc_text">
5517
5518<h5>Syntax:</h5>
5519<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5520 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5521</pre>
5522
5523<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5524<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5525 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5526
5527<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5528<p>The argument to this intrinsic indicates which function to return the frame
5529 pointer for. Zero indicates the calling function, one indicates its caller,
5530 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5531
5532<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5533<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5534 indicating the frame address of the specified call frame, or zero if it
5535 cannot be identified. The value returned by this intrinsic is likely to be
5536 incorrect or 0 for arguments other than zero, so it should only be used for
5537 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5538
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5539<p>Note that calling this intrinsic does not prevent function inlining or other
5540 aggressive transformations, so the value returned may not be that of the
5541 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5542
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5543</div>
5544
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5545<!-- _______________________________________________________________________ -->
5546<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5547 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5548</div>
5549
5550<div class="doc_text">
5551
5552<h5>Syntax:</h5>
5553<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5554 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5555</pre>
5556
5557<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5558<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5559 of the function stack, for use
5560 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5561 useful for implementing language features like scoped automatic variable
5562 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5563
5564<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5565<p>This intrinsic returns a opaque pointer value that can be passed
5566 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5567 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5568 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5569 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5570 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5571 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5572
5573</div>
5574
5575<!-- _______________________________________________________________________ -->
5576<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5577 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5578</div>
5579
5580<div class="doc_text">
5581
5582<h5>Syntax:</h5>
5583<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5584 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5585</pre>
5586
5587<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5588<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5589 the function stack to the state it was in when the
5590 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5591 executed. This is useful for implementing language features like scoped
5592 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5593
5594<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5595<p>See the description
5596 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5597
5598</div>
5599
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5600<!-- _______________________________________________________________________ -->
5601<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5602 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5603</div>
5604
5605<div class="doc_text">
5606
5607<h5>Syntax:</h5>
5608<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5609 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]5610</pre>
5611
5612<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5613<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5614 insert a prefetch instruction if supported; otherwise, it is a noop.
5615 Prefetches have no effect on the behavior of the program but can change its
5616 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5617
5618<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5619<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5620 specifier determining if the fetch should be for a read (0) or write (1),
5621 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5622 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5623 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5624
5625<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5626<p>This intrinsic does not modify the behavior of the program. In particular,
5627 prefetches cannot trap and do not produce a value. On targets that support
5628 this intrinsic, the prefetch can provide hints to the processor cache for
5629 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5630
5631</div>
5632
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5633<!-- _______________________________________________________________________ -->
5634<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5635 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5636</div>
5637
5638<div class="doc_text">
5639
5640<h5>Syntax:</h5>
5641<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5642 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5643</pre>
5644
5645<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5646<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5647 Counter (PC) in a region of code to simulators and other tools. The method
5648 is target specific, but it is expected that the marker will use exported
5649 symbols to transmit the PC of the marker. The marker makes no guarantees
5650 that it will remain with any specific instruction after optimizations. It is
5651 possible that the presence of a marker will inhibit optimizations. The
5652 intended use is to be inserted after optimizations to allow correlations of
5653 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5654
5655<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5656<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5657
5658<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5659<p>This intrinsic does not modify the behavior of the program. Backends that do
5660 not support this intrinisic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5661
5662</div>
5663
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5664<!-- _______________________________________________________________________ -->
5665<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5666 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5667</div>
5668
5669<div class="doc_text">
5670
5671<h5>Syntax:</h5>
5672<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5673 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5674</pre>
5675
5676<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5677<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5678 counter register (or similar low latency, high accuracy clocks) on those
5679 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5680 should map to RPCC. As the backing counters overflow quickly (on the order
5681 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5682
5683<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5684<p>When directly supported, reading the cycle counter should not modify any
5685 memory. Implementations are allowed to either return a application specific
5686 value or a system wide value. On backends without support, this is lowered
5687 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5688
5689</div>
5690
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5691<!-- ======================================================================= -->
5692<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5693 <a name="int_libc">Standard C Library Intrinsics</a>
5694</div>
5695
5696<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5697
5698<p>LLVM provides intrinsics for a few important standard C library functions.
5699 These intrinsics allow source-language front-ends to pass information about
5700 the alignment of the pointer arguments to the code generator, providing
5701 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5702
5703</div>
5704
5705<!-- _______________________________________________________________________ -->
5706<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5707 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5708</div>
5709
5710<div class="doc_text">
5711
5712<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5713<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5714 integer bit width. Not all targets support all bit widths however.</p>
5715
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5716<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5717 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5718 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5719 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5720 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5721 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5722 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5723 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5724 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5725</pre>
5726
5727<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5728<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5729 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5730
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5731<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5732 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5733
5734<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5735<p>The first argument is a pointer to the destination, the second is a pointer
5736 to the source. The third argument is an integer argument specifying the
5737 number of bytes to copy, and the fourth argument is the alignment of the
5738 source and destination locations.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5739
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5740<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5741 then the caller guarantees that both the source and destination pointers are
5742 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5743
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5744<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5745<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5746 source location to the destination location, which are not allowed to
5747 overlap. It copies "len" bytes of memory over. If the argument is known to
5748 be aligned to some boundary, this can be specified as the fourth argument,
5749 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5750
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5751</div>
5752
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5753<!-- _______________________________________________________________________ -->
5754<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5755 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5756</div>
5757
5758<div class="doc_text">
5759
5760<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5761<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]5762 width. Not all targets support all bit widths however.</p>
5763
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5764<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5765 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5766 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5767 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5768 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5769 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5770 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5771 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5772 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5773</pre>
5774
5775<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5776<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5777 source location to the destination location. It is similar to the
5778 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5779 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5780
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5781<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5782 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5783
5784<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5785<p>The first argument is a pointer to the destination, the second is a pointer
5786 to the source. The third argument is an integer argument specifying the
5787 number of bytes to copy, and the fourth argument is the alignment of the
5788 source and destination locations.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5789
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5790<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5791 then the caller guarantees that the source and destination pointers are
5792 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5793
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5794<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5795<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5796 source location to the destination location, which may overlap. It copies
5797 "len" bytes of memory over. If the argument is known to be aligned to some
5798 boundary, this can be specified as the fourth argument, otherwise it should
5799 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5800
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5801</div>
5802
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5803<!-- _______________________________________________________________________ -->
5804<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5805 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5806</div>
5807
5808<div class="doc_text">
5809
5810<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5811<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]5812 width. Not all targets support all bit widths however.</p>
5813
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5814<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5815 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5816 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5817 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5818 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5819 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5820 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5821 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5822 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5823</pre>
5824
5825<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5826<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5827 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5828
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5829<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5830 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5831
5832<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5833<p>The first argument is a pointer to the destination to fill, the second is the
5834 byte value to fill it with, the third argument is an integer argument
5835 specifying the number of bytes to fill, and the fourth argument is the known
5836 alignment of destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5837
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5838<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5839 then the caller guarantees that the destination pointer is aligned to that
5840 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5841
5842<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5843<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5844 at the destination location. If the argument is known to be aligned to some
5845 boundary, this can be specified as the fourth argument, otherwise it should
5846 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5847
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5848</div>
5849
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5850<!-- _______________________________________________________________________ -->
5851<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5852 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5853</div>
5854
5855<div class="doc_text">
5856
5857<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5858<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5859 floating point or vector of floating point type. Not all targets support all
5860 types however.</p>
5861
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5862<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5863 declare float @llvm.sqrt.f32(float %Val)
5864 declare double @llvm.sqrt.f64(double %Val)
5865 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5866 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5867 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5868</pre>
5869
5870<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5871<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5872 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5873 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5874 behavior for negative numbers other than -0.0 (which allows for better
5875 optimization, because there is no need to worry about errno being
5876 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]5877
5878<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5879<p>The argument and return value are floating point numbers of the same
5880 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5881
5882<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5883<p>This function returns the sqrt of the specified operand if it is a
5884 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5885
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5886</div>
5887
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5888<!-- _______________________________________________________________________ -->
5889<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5890 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5891</div>
5892
5893<div class="doc_text">
5894
5895<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5896<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5897 floating point or vector of floating point type. Not all targets support all
5898 types however.</p>
5899
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5900<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5901 declare float @llvm.powi.f32(float %Val, i32 %power)
5902 declare double @llvm.powi.f64(double %Val, i32 %power)
5903 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5904 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5905 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5906</pre>
5907
5908<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5909<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5910 specified (positive or negative) power. The order of evaluation of
5911 multiplications is not defined. When a vector of floating point type is
5912 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5913
5914<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5915<p>The second argument is an integer power, and the first is a value to raise to
5916 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5917
5918<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5919<p>This function returns the first value raised to the second power with an
5920 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5921
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5922</div>
5923
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5924<!-- _______________________________________________________________________ -->
5925<div class="doc_subsubsection">
5926 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5927</div>
5928
5929<div class="doc_text">
5930
5931<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5932<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5933 floating point or vector of floating point type. Not all targets support all
5934 types however.</p>
5935
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5936<pre>
5937 declare float @llvm.sin.f32(float %Val)
5938 declare double @llvm.sin.f64(double %Val)
5939 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5940 declare fp128 @llvm.sin.f128(fp128 %Val)
5941 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5942</pre>
5943
5944<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5945<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5946
5947<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5948<p>The argument and return value are floating point numbers of the same
5949 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5950
5951<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5952<p>This function returns the sine of the specified operand, returning the same
5953 values as the libm <tt>sin</tt> functions would, and handles error conditions
5954 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5955
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5956</div>
5957
5958<!-- _______________________________________________________________________ -->
5959<div class="doc_subsubsection">
5960 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5961</div>
5962
5963<div class="doc_text">
5964
5965<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5966<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5967 floating point or vector of floating point type. Not all targets support all
5968 types however.</p>
5969
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5970<pre>
5971 declare float @llvm.cos.f32(float %Val)
5972 declare double @llvm.cos.f64(double %Val)
5973 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5974 declare fp128 @llvm.cos.f128(fp128 %Val)
5975 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5976</pre>
5977
5978<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5979<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5980
5981<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5982<p>The argument and return value are floating point numbers of the same
5983 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5984
5985<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5986<p>This function returns the cosine of the specified operand, returning the same
5987 values as the libm <tt>cos</tt> functions would, and handles error conditions
5988 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5989
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5990</div>
5991
5992<!-- _______________________________________________________________________ -->
5993<div class="doc_subsubsection">
5994 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5995</div>
5996
5997<div class="doc_text">
5998
5999<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6000<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6001 floating point or vector of floating point type. Not all targets support all
6002 types however.</p>
6003
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6004<pre>
6005 declare float @llvm.pow.f32(float %Val, float %Power)
6006 declare double @llvm.pow.f64(double %Val, double %Power)
6007 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6008 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6009 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6010</pre>
6011
6012<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6013<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6014 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6015
6016<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6017<p>The second argument is a floating point power, and the first is a value to
6018 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6019
6020<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6021<p>This function returns the first value raised to the second power, returning
6022 the same values as the libm <tt>pow</tt> functions would, and handles error
6023 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6024
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6025</div>
6026
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6027<!-- ======================================================================= -->
6028<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6029 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6030</div>
6031
6032<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6033
6034<p>LLVM provides intrinsics for a few important bit manipulation operations.
6035 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6036
6037</div>
6038
6039<!-- _______________________________________________________________________ -->
6040<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6041 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6042</div>
6043
6044<div class="doc_text">
6045
6046<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6047<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6048 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6049
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6050<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6051 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6052 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6053 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6054</pre>
6055
6056<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6057<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6058 values with an even number of bytes (positive multiple of 16 bits). These
6059 are useful for performing operations on data that is not in the target's
6060 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6061
6062<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6063<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6064 and low byte of the input i16 swapped. Similarly,
6065 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6066 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6067 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6068 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6069 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6070 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6071
6072</div>
6073
6074<!-- _______________________________________________________________________ -->
6075<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6076 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6077</div>
6078
6079<div class="doc_text">
6080
6081<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6082<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]6083 width. Not all targets support all bit widths however.</p>
6084
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6085<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6086 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6087 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6088 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6089 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6090 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6091</pre>
6092
6093<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6094<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6095 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6096
6097<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6098<p>The only argument is the value to be counted. The argument may be of any
6099 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6100
6101<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6102<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]6103
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6104</div>
6105
6106<!-- _______________________________________________________________________ -->
6107<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6108 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6109</div>
6110
6111<div class="doc_text">
6112
6113<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6114<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6115 integer bit width. Not all targets support all bit widths however.</p>
6116
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6117<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6118 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6119 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6120 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6121 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6122 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6123</pre>
6124
6125<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6126<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6127 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6128
6129<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6130<p>The only argument is the value to be counted. The argument may be of any
6131 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6132
6133<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6134<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6135 zeros in a variable. If the src == 0 then the result is the size in bits of
6136 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6137
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6138</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6139
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6140<!-- _______________________________________________________________________ -->
6141<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6142 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6143</div>
6144
6145<div class="doc_text">
6146
6147<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6148<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6149 integer bit width. Not all targets support all bit widths however.</p>
6150
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6151<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6152 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6153 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6154 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6155 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6156 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6157</pre>
6158
6159<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6160<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6161 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6162
6163<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6164<p>The only argument is the value to be counted. The argument may be of any
6165 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6166
6167<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6168<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6169 zeros in a variable. If the src == 0 then the result is the size in bits of
6170 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6171
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6172</div>
6173
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6174<!-- ======================================================================= -->
6175<div class="doc_subsection">
6176 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6177</div>
6178
6179<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6180
6181<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6182
6183</div>
6184
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6185<!-- _______________________________________________________________________ -->
6186<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6187 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6188</div>
6189
6190<div class="doc_text">
6191
6192<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6193<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]6194 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6195
6196<pre>
6197 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6198 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6199 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6200</pre>
6201
6202<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6203<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6204 a signed addition of the two arguments, and indicate whether an overflow
6205 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6206
6207<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6208<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]6209 be of integer types of any bit width, but they must have the same bit
6210 width. The second element of the result structure must be of
6211 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6212 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6213
6214<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6215<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6216 a signed addition of the two variables. They return a structure &mdash; the
6217 first element of which is the signed summation, and the second element of
6218 which is a bit specifying if the signed summation resulted in an
6219 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6220
6221<h5>Examples:</h5>
6222<pre>
6223 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6224 %sum = extractvalue {i32, i1} %res, 0
6225 %obit = extractvalue {i32, i1} %res, 1
6226 br i1 %obit, label %overflow, label %normal
6227</pre>
6228
6229</div>
6230
6231<!-- _______________________________________________________________________ -->
6232<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6233 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6234</div>
6235
6236<div class="doc_text">
6237
6238<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6239<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]6240 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6241
6242<pre>
6243 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6244 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6245 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6246</pre>
6247
6248<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6249<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6250 an unsigned addition of the two arguments, and indicate whether a carry
6251 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6252
6253<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6254<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]6255 be of integer types of any bit width, but they must have the same bit
6256 width. The second element of the result structure must be of
6257 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6258 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6259
6260<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6261<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6262 an unsigned addition of the two arguments. They return a structure &mdash;
6263 the first element of which is the sum, and the second element of which is a
6264 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6265
6266<h5>Examples:</h5>
6267<pre>
6268 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6269 %sum = extractvalue {i32, i1} %res, 0
6270 %obit = extractvalue {i32, i1} %res, 1
6271 br i1 %obit, label %carry, label %normal
6272</pre>
6273
6274</div>
6275
6276<!-- _______________________________________________________________________ -->
6277<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6278 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6279</div>
6280
6281<div class="doc_text">
6282
6283<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6284<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]6285 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6286
6287<pre>
6288 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6289 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6290 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6291</pre>
6292
6293<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6294<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6295 a signed subtraction of the two arguments, and indicate whether an overflow
6296 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6297
6298<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6299<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]6300 be of integer types of any bit width, but they must have the same bit
6301 width. The second element of the result structure must be of
6302 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6303 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6304
6305<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6306<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6307 a signed subtraction of the two arguments. They return a structure &mdash;
6308 the first element of which is the subtraction, and the second element of
6309 which is a bit specifying if the signed subtraction resulted in an
6310 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6311
6312<h5>Examples:</h5>
6313<pre>
6314 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6315 %sum = extractvalue {i32, i1} %res, 0
6316 %obit = extractvalue {i32, i1} %res, 1
6317 br i1 %obit, label %overflow, label %normal
6318</pre>
6319
6320</div>
6321
6322<!-- _______________________________________________________________________ -->
6323<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6324 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6325</div>
6326
6327<div class="doc_text">
6328
6329<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6330<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]6331 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6332
6333<pre>
6334 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6335 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6336 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6337</pre>
6338
6339<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6340<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6341 an unsigned subtraction of the two arguments, and indicate whether an
6342 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6343
6344<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6345<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]6346 be of integer types of any bit width, but they must have the same bit
6347 width. The second element of the result structure must be of
6348 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6349 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6350
6351<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6352<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6353 an unsigned subtraction of the two arguments. They return a structure &mdash;
6354 the first element of which is the subtraction, and the second element of
6355 which is a bit specifying if the unsigned subtraction resulted in an
6356 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6357
6358<h5>Examples:</h5>
6359<pre>
6360 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6361 %sum = extractvalue {i32, i1} %res, 0
6362 %obit = extractvalue {i32, i1} %res, 1
6363 br i1 %obit, label %overflow, label %normal
6364</pre>
6365
6366</div>
6367
6368<!-- _______________________________________________________________________ -->
6369<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6370 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6371</div>
6372
6373<div class="doc_text">
6374
6375<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6376<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]6377 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6378
6379<pre>
6380 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6381 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6382 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6383</pre>
6384
6385<h5>Overview:</h5>
6386
6387<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6388 a signed multiplication of the two arguments, and indicate whether an
6389 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6390
6391<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6392<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]6393 be of integer types of any bit width, but they must have the same bit
6394 width. The second element of the result structure must be of
6395 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6396 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6397
6398<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6399<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6400 a signed multiplication of the two arguments. They return a structure &mdash;
6401 the first element of which is the multiplication, and the second element of
6402 which is a bit specifying if the signed multiplication resulted in an
6403 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6404
6405<h5>Examples:</h5>
6406<pre>
6407 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6408 %sum = extractvalue {i32, i1} %res, 0
6409 %obit = extractvalue {i32, i1} %res, 1
6410 br i1 %obit, label %overflow, label %normal
6411</pre>
6412
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6413</div>
6414
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6415<!-- _______________________________________________________________________ -->
6416<div class="doc_subsubsection">
6417 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6418</div>
6419
6420<div class="doc_text">
6421
6422<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6423<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]6424 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6425
6426<pre>
6427 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6428 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6429 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6430</pre>
6431
6432<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6433<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6434 a unsigned multiplication of the two arguments, and indicate whether an
6435 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6436
6437<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6438<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]6439 be of integer types of any bit width, but they must have the same bit
6440 width. The second element of the result structure must be of
6441 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6442 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6443
6444<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6445<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6446 an unsigned multiplication of the two arguments. They return a structure
6447 &mdash; the first element of which is the multiplication, and the second
6448 element of which is a bit specifying if the unsigned multiplication resulted
6449 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6450
6451<h5>Examples:</h5>
6452<pre>
6453 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6454 %sum = extractvalue {i32, i1} %res, 0
6455 %obit = extractvalue {i32, i1} %res, 1
6456 br i1 %obit, label %overflow, label %normal
6457</pre>
6458
6459</div>
6460
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6461<!-- ======================================================================= -->
6462<div class="doc_subsection">
6463 <a name="int_debugger">Debugger Intrinsics</a>
6464</div>
6465
6466<div class="doc_text">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6467
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6468<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6469 prefix), are described in
6470 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6471 Level Debugging</a> document.</p>
6472
6473</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6474
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6475<!-- ======================================================================= -->
6476<div class="doc_subsection">
6477 <a name="int_eh">Exception Handling Intrinsics</a>
6478</div>
6479
6480<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6481
6482<p>The LLVM exception handling intrinsics (which all start with
6483 <tt>llvm.eh.</tt> prefix), are described in
6484 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6485 Handling</a> document.</p>
6486
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6487</div>
6488
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6489<!-- ======================================================================= -->
6490<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6491 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6492</div>
6493
6494<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6495
6496<p>This intrinsic makes it possible to excise one parameter, marked with
6497 the <tt>nest</tt> attribute, from a function. The result is a callable
6498 function pointer lacking the nest parameter - the caller does not need to
6499 provide a value for it. Instead, the value to use is stored in advance in a
6500 "trampoline", a block of memory usually allocated on the stack, which also
6501 contains code to splice the nest value into the argument list. This is used
6502 to implement the GCC nested function address extension.</p>
6503
6504<p>For example, if the function is
6505 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6506 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6507 follows:</p>
6508
6509<div class="doc_code">
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6510<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6511 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6512 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6513 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6514 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6515</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6516</div>
6517
6518<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6519 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6520
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6521</div>
6522
6523<!-- _______________________________________________________________________ -->
6524<div class="doc_subsubsection">
6525 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6526</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6527
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6528<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6529
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6530<h5>Syntax:</h5>
6531<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6532 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]6533</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6534
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6535<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6536<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6537 function pointer suitable for executing it.</p>
6538
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6539<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6540<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6541 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6542 sufficiently aligned block of memory; this memory is written to by the
6543 intrinsic. Note that the size and the alignment are target-specific - LLVM
6544 currently provides no portable way of determining them, so a front-end that
6545 generates this intrinsic needs to have some target-specific knowledge.
6546 The <tt>func</tt> argument must hold a function bitcast to
6547 an <tt>i8*</tt>.</p>
6548
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6549<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6550<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6551 dependent code, turning it into a function. A pointer to this function is
6552 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6553 function pointer type</a> before being called. The new function's signature
6554 is the same as that of <tt>func</tt> with any arguments marked with
6555 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6556 is allowed, and it must be of pointer type. Calling the new function is
6557 equivalent to calling <tt>func</tt> with the same argument list, but
6558 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6559 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6560 by <tt>tramp</tt> is modified, then the effect of any later call to the
6561 returned function pointer is undefined.</p>
6562
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6563</div>
6564
6565<!-- ======================================================================= -->
6566<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6567 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6568</div>
6569
6570<div class="doc_text">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6571
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6572<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6573 hardware constructs for atomic operations and memory synchronization. This
6574 provides an interface to the hardware, not an interface to the programmer. It
6575 is aimed at a low enough level to allow any programming models or APIs
6576 (Application Programming Interfaces) which need atomic behaviors to map
6577 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6578 hardware provides a "universal IR" for source languages, it also provides a
6579 starting point for developing a "universal" atomic operation and
6580 synchronization IR.</p>
6581
6582<p>These do <em>not</em> form an API such as high-level threading libraries,
6583 software transaction memory systems, atomic primitives, and intrinsic
6584 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6585 application libraries. The hardware interface provided by LLVM should allow
6586 a clean implementation of all of these APIs and parallel programming models.
6587 No one model or paradigm should be selected above others unless the hardware
6588 itself ubiquitously does so.</p>
6589
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6590</div>
6591
6592<!-- _______________________________________________________________________ -->
6593<div class="doc_subsubsection">
6594 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6595</div>
6596<div class="doc_text">
6597<h5>Syntax:</h5>
6598<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6599 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]6600</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6601
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6602<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6603<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6604 specific pairs of memory access types.</p>
6605
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6606<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6607<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6608 The first four arguments enables a specific barrier as listed below. The
6609 fith argument specifies that the barrier applies to io or device or uncached
6610 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6611
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6612<ul>
6613 <li><tt>ll</tt>: load-load barrier</li>
6614 <li><tt>ls</tt>: load-store barrier</li>
6615 <li><tt>sl</tt>: store-load barrier</li>
6616 <li><tt>ss</tt>: store-store barrier</li>
6617 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6618</ul>
6619
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6620<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6621<p>This intrinsic causes the system to enforce some ordering constraints upon
6622 the loads and stores of the program. This barrier does not
6623 indicate <em>when</em> any events will occur, it only enforces
6624 an <em>order</em> in which they occur. For any of the specified pairs of load
6625 and store operations (f.ex. load-load, or store-load), all of the first
6626 operations preceding the barrier will complete before any of the second
6627 operations succeeding the barrier begin. Specifically the semantics for each
6628 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6629
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6630<ul>
6631 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6632 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6633 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6634 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6635 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6636 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6637 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6638 load after the barrier begins.</li>
6639</ul>
6640
6641<p>These semantics are applied with a logical "and" behavior when more than one
6642 is enabled in a single memory barrier intrinsic.</p>
6643
6644<p>Backends may implement stronger barriers than those requested when they do
6645 not support as fine grained a barrier as requested. Some architectures do
6646 not need all types of barriers and on such architectures, these become
6647 noops.</p>
6648
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6649<h5>Example:</h5>
6650<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6651%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6652%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6653 store i32 4, %ptr
6654
6655%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6656 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6657 <i>; guarantee the above finishes</i>
6658 store i32 8, %ptr <i>; before this begins</i>
6659</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6660
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6661</div>
6662
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6663<!-- _______________________________________________________________________ -->
6664<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6665 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6666</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6667
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6668<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6669
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6670<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6671<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6672 any integer bit width and for different address spaces. Not all targets
6673 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6674
6675<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6676 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6677 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6678 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6679 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]6680</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6681
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6682<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6683<p>This loads a value in memory and compares it to a given value. If they are
6684 equal, it stores a new value into the memory.</p>
6685
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6686<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6687<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6688 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6689 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6690 this integer type. While any bit width integer may be used, targets may only
6691 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6692
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6693<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6694<p>This entire intrinsic must be executed atomically. It first loads the value
6695 in memory pointed to by <tt>ptr</tt> and compares it with the
6696 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6697 memory. The loaded value is yielded in all cases. This provides the
6698 equivalent of an atomic compare-and-swap operation within the SSA
6699 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6700
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6701<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6702<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6703%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6704%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6705 store i32 4, %ptr
6706
6707%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6708%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6709 <i>; yields {i32}:result1 = 4</i>
6710%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6711%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6712
6713%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6714%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6715 <i>; yields {i32}:result2 = 8</i>
6716%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6717
6718%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6719</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6720
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6721</div>
6722
6723<!-- _______________________________________________________________________ -->
6724<div class="doc_subsubsection">
6725 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6726</div>
6727<div class="doc_text">
6728<h5>Syntax:</h5>
6729
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6730<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6731 integer bit width. Not all targets support all bit widths however.</p>
6732
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6733<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6734 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6735 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6736 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6737 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]6738</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6739
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6740<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6741<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6742 the value from memory. It then stores the value in <tt>val</tt> in the memory
6743 at <tt>ptr</tt>.</p>
6744
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6745<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6746<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6747 the <tt>val</tt> argument and the result must be integers of the same bit
6748 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6749 integer type. The targets may only lower integer representations they
6750 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6751
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6752<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6753<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6754 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6755 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6756
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6757<h5>Examples:</h5>
6758<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6759%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6760%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6761 store i32 4, %ptr
6762
6763%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6764%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6765 <i>; yields {i32}:result1 = 4</i>
6766%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6767%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6768
6769%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6770%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6771 <i>; yields {i32}:result2 = 8</i>
6772
6773%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6774%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6775</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6777</div>
6778
6779<!-- _______________________________________________________________________ -->
6780<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6781 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6782
6783</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6784
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6785<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6786
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6787<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6788<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6789 any integer bit width. Not all targets support all bit widths however.</p>
6790
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6791<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6792 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6793 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6794 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6795 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]6796</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6797
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6798<h5>Overview:</h5>
6799<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6800 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6801
6802<h5>Arguments:</h5>
6803<p>The intrinsic takes two arguments, the first a pointer to an integer value
6804 and the second an integer value. The result is also an integer value. These
6805 integer types can have any bit width, but they must all have the same bit
6806 width. The targets may only lower integer representations they support.</p>
6807
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6808<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6809<p>This intrinsic does a series of operations atomically. It first loads the
6810 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6811 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]6812
6813<h5>Examples:</h5>
6814<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6815%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6816%ptr = bitcast i8* %mallocP to i32*
6817 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6818%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6819 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6820%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6821 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6822%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6823 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6824%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6825</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6826
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6827</div>
6828
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6829<!-- _______________________________________________________________________ -->
6830<div class="doc_subsubsection">
6831 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6832
6833</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6834
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6835<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6836
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6837<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6838<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6839 any integer bit width and for different address spaces. Not all targets
6840 support all bit widths however.</p>
6841
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6842<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6843 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6844 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6845 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6846 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]6847</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6848
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6849<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6850<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6851 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6852
6853<h5>Arguments:</h5>
6854<p>The intrinsic takes two arguments, the first a pointer to an integer value
6855 and the second an integer value. The result is also an integer value. These
6856 integer types can have any bit width, but they must all have the same bit
6857 width. The targets may only lower integer representations they support.</p>
6858
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6859<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6860<p>This intrinsic does a series of operations atomically. It first loads the
6861 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6862 result to <tt>ptr</tt>. It yields the original value stored
6863 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6864
6865<h5>Examples:</h5>
6866<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6867%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6868%ptr = bitcast i8* %mallocP to i32*
6869 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6870%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6871 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6872%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6873 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6874%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6875 <i>; yields {i32}:result3 = 2</i>
6876%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6877</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6878
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6879</div>
6880
6881<!-- _______________________________________________________________________ -->
6882<div class="doc_subsubsection">
6883 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6884 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6885 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6886 <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]6887</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6888
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6889<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6890
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6891<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6892<p>These are overloaded intrinsics. You can
6893 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6894 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6895 bit width and for different address spaces. Not all targets support all bit
6896 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6897
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6898<pre>
6899 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6900 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6901 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6902 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]6903</pre>
6904
6905<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6906 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6907 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6908 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6909 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]6910</pre>
6911
6912<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6913 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6914 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6915 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6916 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]6917</pre>
6918
6919<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6920 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6921 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6922 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6923 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]6924</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6925
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6926<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6927<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6928 the value stored in memory at <tt>ptr</tt>. It yields the original value
6929 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6930
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6931<h5>Arguments:</h5>
6932<p>These intrinsics take two arguments, the first a pointer to an integer value
6933 and the second an integer value. The result is also an integer value. These
6934 integer types can have any bit width, but they must all have the same bit
6935 width. The targets may only lower integer representations they support.</p>
6936
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6937<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6938<p>These intrinsics does a series of operations atomically. They first load the
6939 value stored at <tt>ptr</tt>. They then do the bitwise
6940 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6941 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6942
6943<h5>Examples:</h5>
6944<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6945%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6946%ptr = bitcast i8* %mallocP to i32*
6947 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6948%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6949 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6950%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6951 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6952%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6953 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6954%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6955 <i>; yields {i32}:result3 = FF</i>
6956%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6957</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6958
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6959</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6960
6961<!-- _______________________________________________________________________ -->
6962<div class="doc_subsubsection">
6963 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6964 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6965 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6966 <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]6967</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6968
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6969<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6970
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6971<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6972<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6973 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6974 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6975 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6976
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6977<pre>
6978 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6979 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6980 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6981 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]6982</pre>
6983
6984<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6985 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6986 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6987 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6988 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]6989</pre>
6990
6991<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6992 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6993 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6994 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6995 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]6996</pre>
6997
6998<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6999 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7000 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7001 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7002 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]7003</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7004
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7005<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7006<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7007 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7008 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7009
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7010<h5>Arguments:</h5>
7011<p>These intrinsics take two arguments, the first a pointer to an integer value
7012 and the second an integer value. The result is also an integer value. These
7013 integer types can have any bit width, but they must all have the same bit
7014 width. The targets may only lower integer representations they support.</p>
7015
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7016<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7017<p>These intrinsics does a series of operations atomically. They first load the
7018 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7019 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7020 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7021
7022<h5>Examples:</h5>
7023<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7024%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7025%ptr = bitcast i8* %mallocP to i32*
7026 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7027%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7028 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7029%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7030 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7031%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7032 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7033%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7034 <i>; yields {i32}:result3 = 8</i>
7035%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7036</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7037
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7038</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7039
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7040
7041<!-- ======================================================================= -->
7042<div class="doc_subsection">
7043 <a name="int_memorymarkers">Memory Use Markers</a>
7044</div>
7045
7046<div class="doc_text">
7047
7048<p>This class of intrinsics exists to information about the lifetime of memory
7049 objects and ranges where variables are immutable.</p>
7050
7051</div>
7052
7053<!-- _______________________________________________________________________ -->
7054<div class="doc_subsubsection">
7055 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7056</div>
7057
7058<div class="doc_text">
7059
7060<h5>Syntax:</h5>
7061<pre>
7062 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7063</pre>
7064
7065<h5>Overview:</h5>
7066<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7067 object's lifetime.</p>
7068
7069<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7070<p>The first argument is a constant integer representing the size of the
7071 object, or -1 if it is variable sized. The second argument is a pointer to
7072 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7073
7074<h5>Semantics:</h5>
7075<p>This intrinsic indicates that before this point in the code, the value of the
7076 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]7077 never be used and has an undefined value. A load from the pointer that
7078 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7079 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7080
7081</div>
7082
7083<!-- _______________________________________________________________________ -->
7084<div class="doc_subsubsection">
7085 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7086</div>
7087
7088<div class="doc_text">
7089
7090<h5>Syntax:</h5>
7091<pre>
7092 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7093</pre>
7094
7095<h5>Overview:</h5>
7096<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7097 object's lifetime.</p>
7098
7099<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7100<p>The first argument is a constant integer representing the size of the
7101 object, or -1 if it is variable sized. The second argument is a pointer to
7102 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7103
7104<h5>Semantics:</h5>
7105<p>This intrinsic indicates that after this point in the code, the value of the
7106 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7107 never be used and has an undefined value. Any stores into the memory object
7108 following this intrinsic may be removed as dead.
7109
7110</div>
7111
7112<!-- _______________________________________________________________________ -->
7113<div class="doc_subsubsection">
7114 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7115</div>
7116
7117<div class="doc_text">
7118
7119<h5>Syntax:</h5>
7120<pre>
7121 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7122</pre>
7123
7124<h5>Overview:</h5>
7125<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7126 a memory object will not change.</p>
7127
7128<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7129<p>The first argument is a constant integer representing the size of the
7130 object, or -1 if it is variable sized. The second argument is a pointer to
7131 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7132
7133<h5>Semantics:</h5>
7134<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7135 the return value, the referenced memory location is constant and
7136 unchanging.</p>
7137
7138</div>
7139
7140<!-- _______________________________________________________________________ -->
7141<div class="doc_subsubsection">
7142 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7143</div>
7144
7145<div class="doc_text">
7146
7147<h5>Syntax:</h5>
7148<pre>
7149 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7150</pre>
7151
7152<h5>Overview:</h5>
7153<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7154 a memory object are mutable.</p>
7155
7156<h5>Arguments:</h5>
7157<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7158 The second argument is a constant integer representing the size of the
7159 object, or -1 if it is variable sized and the third argument is a pointer
7160 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7161
7162<h5>Semantics:</h5>
7163<p>This intrinsic indicates that the memory is mutable again.</p>
7164
7165</div>
7166
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7167<!-- ======================================================================= -->
7168<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7169 <a name="int_general">General Intrinsics</a>
7170</div>
7171
7172<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7173
7174<p>This class of intrinsics is designed to be generic and has no specific
7175 purpose.</p>
7176
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7177</div>
7178
7179<!-- _______________________________________________________________________ -->
7180<div class="doc_subsubsection">
7181 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7182</div>
7183
7184<div class="doc_text">
7185
7186<h5>Syntax:</h5>
7187<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]7188 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]7189</pre>
7190
7191<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7192<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7193
7194<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7195<p>The first argument is a pointer to a value, the second is a pointer to a
7196 global string, the third is a pointer to a global string which is the source
7197 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7198
7199<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7200<p>This intrinsic allows annotation of local variables with arbitrary strings.
7201 This can be useful for special purpose optimizations that want to look for
7202 these annotations. These have no other defined use, they are ignored by code
7203 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7204
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7205</div>
7206
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7207<!-- _______________________________________________________________________ -->
7208<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7209 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7210</div>
7211
7212<div class="doc_text">
7213
7214<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7215<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7216 any integer bit width.</p>
7217
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7218<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]7219 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7220 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7221 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7222 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7223 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]7224</pre>
7225
7226<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7227<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7228
7229<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7230<p>The first argument is an integer value (result of some expression), the
7231 second is a pointer to a global string, the third is a pointer to a global
7232 string which is the source file name, and the last argument is the line
7233 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7234
7235<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7236<p>This intrinsic allows annotations to be put on arbitrary expressions with
7237 arbitrary strings. This can be useful for special purpose optimizations that
7238 want to look for these annotations. These have no other defined use, they
7239 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7240
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7241</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7242
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7243<!-- _______________________________________________________________________ -->
7244<div class="doc_subsubsection">
7245 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7246</div>
7247
7248<div class="doc_text">
7249
7250<h5>Syntax:</h5>
7251<pre>
7252 declare void @llvm.trap()
7253</pre>
7254
7255<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7256<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7257
7258<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7259<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7260
7261<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7262<p>This intrinsics is lowered to the target dependent trap instruction. If the
7263 target does not have a trap instruction, this intrinsic will be lowered to
7264 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7265
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7266</div>
7267
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7268<!-- _______________________________________________________________________ -->
7269<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7270 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7271</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7272
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7273<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7274
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7275<h5>Syntax:</h5>
7276<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7277 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7278</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7279
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7280<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7281<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7282 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7283 ensure that it is placed on the stack before local variables.</p>
7284
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7285<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7286<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7287 arguments. The first argument is the value loaded from the stack
7288 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7289 that has enough space to hold the value of the guard.</p>
7290
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7291<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7292<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7293 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7294 stack. This is to ensure that if a local variable on the stack is
7295 overwritten, it will destroy the value of the guard. When the function exits,
7296 the guard on the stack is checked against the original guard. If they're
7297 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7298 function.</p>
7299
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7300</div>
7301
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7302<!-- _______________________________________________________________________ -->
7303<div class="doc_subsubsection">
7304 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7305</div>
7306
7307<div class="doc_text">
7308
7309<h5>Syntax:</h5>
7310<pre>
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7311 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7312 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7313</pre>
7314
7315<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7316<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopher3070e162010-01-08 21:42:39 +0000[diff] [blame]7317 to the optimizers to discover at compile time either a) when an
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7318 operation like memcpy will either overflow a buffer that corresponds to
7319 an object, or b) to determine that a runtime check for overflow isn't
7320 necessary. An object in this context means an allocation of a
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7321 specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7322
7323<h5>Arguments:</h5>
7324<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7325 argument is a pointer to or into the <tt>object</tt>. The second argument
7326 is a boolean 0 or 1. This argument determines whether you want the
7327 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7328 1, variables are not allowed.</p>
7329
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7330<h5>Semantics:</h5>
7331<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7332 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7333 (depending on the <tt>type</tt> argument if the size cannot be determined
7334 at compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7335
7336</div>
7337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7338<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7339<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7340<address>
7341 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7342 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7343 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7344 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]7345
7346 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]7347 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7348 Last modified: $Date$
7349</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]7350
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]7351</body>
7352</html>