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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / fbff0ec2c7ffcaebd2ab4029c6684d977f553065 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 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 Lattnerfa730212004-12-09 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 Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]28 <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]29 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
30 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
31 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
32 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
33 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
35 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner5a2d8752009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]56 <li><a href="#memmodel">Memory Model for Concurrent Operations</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]57 </ol>
58 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]59 <li><a href="#typesystem">Type System</a>
60 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]62 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]63 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]64 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]65 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]66 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]67 <li><a href="#t_void">Void Type</a></li>
68 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]69 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]70 </ol>
71 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]72 <li><a href="#t_derived">Derived Types</a>
73 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]74 <li><a href="#t_aggregate">Aggregate Types</a>
75 <ol>
76 <li><a href="#t_array">Array Type</a></li>
77 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]78 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]79 <li><a href="#t_vector">Vector Type</a></li>
80 </ol>
81 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]82 <li><a href="#t_function">Function Type</a></li>
83 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
86 </ol>
87 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]88 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]89 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]90 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]91 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
93 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]94 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]95 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]96 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]97 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]98 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]99 <li><a href="#othervalues">Other Values</a>
100 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]101 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]102 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]103 </ol>
104 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]105 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
106 <ol>
107 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]108 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
109 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]110 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
111 Global Variable</a></li>
112 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
113 Global Variable</a></li>
114 </ol>
115 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]116 <li><a href="#instref">Instruction Reference</a>
117 <ol>
118 <li><a href="#terminators">Terminator Instructions</a>
119 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
121 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]122 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]123 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]124 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]126 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]127 </ol>
128 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]129 <li><a href="#binaryops">Binary Operations</a>
130 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]131 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]132 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]137 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
138 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
139 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]140 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
141 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
142 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]143 </ol>
144 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]145 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
146 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]147 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
148 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
149 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]150 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]151 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 </ol>
154 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]155 <li><a href="#vectorops">Vector Operations</a>
156 <ol>
157 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
158 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
159 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]160 </ol>
161 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]162 <li><a href="#aggregateops">Aggregate Operations</a>
163 <ol>
164 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
165 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
166 </ol>
167 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]168 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]169 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]170 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]171 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
172 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
173 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]174 </ol>
175 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]176 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]177 <ol>
178 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
179 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
180 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]183 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
184 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
185 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
186 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]187 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
188 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]189 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]190 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]191 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]192 <li><a href="#otherops">Other Operations</a>
193 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]194 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
195 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]196 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]197 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]198 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]199 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]200 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]201 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]202 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]203 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]204 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]205 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]206 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
207 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]208 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
209 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
210 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]211 </ol>
212 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]213 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
214 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]215 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
216 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
217 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]218 </ol>
219 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]220 <li><a href="#int_codegen">Code Generator Intrinsics</a>
221 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]222 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
223 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
224 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
225 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
226 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
227 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]228 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]229 </ol>
230 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]231 <li><a href="#int_libc">Standard C Library Intrinsics</a>
232 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]233 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]238 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]241 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]243 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]244 </ol>
245 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]246 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]247 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]248 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]249 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
250 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
251 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]252 </ol>
253 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]254 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
255 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]256 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
257 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
260 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]261 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]262 </ol>
263 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]264 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
265 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]266 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
267 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]268 </ol>
269 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]270 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]271 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]272 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]273 <ol>
274 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]275 </ol>
276 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]277 <li><a href="#int_atomics">Atomic intrinsics</a>
278 <ol>
279 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
280 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
281 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
282 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
283 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
284 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
285 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
286 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
287 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
288 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
289 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
290 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
291 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
292 </ol>
293 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]294 <li><a href="#int_memorymarkers">Memory Use Markers</a>
295 <ol>
296 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
297 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
298 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
299 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
300 </ol>
301 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]302 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]303 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]304 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]306 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]307 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]308 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.trap</tt>' Intrinsic</a></li>
310 <li><a href="#int_stackprotector">
311 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]312 <li><a href="#int_objectsize">
313 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]314 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]315 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]316 </ol>
317 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]318</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]319
320<div class="doc_author">
321 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
322 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]323</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]325<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]326<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]328
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]329<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]330
331<p>This document is a reference manual for the LLVM assembly language. LLVM is
332 a Static Single Assignment (SSA) based representation that provides type
333 safety, low-level operations, flexibility, and the capability of representing
334 'all' high-level languages cleanly. It is the common code representation
335 used throughout all phases of the LLVM compilation strategy.</p>
336
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]337</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]338
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]339<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]340<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]341<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]342
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]343<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]344
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]345<p>The LLVM code representation is designed to be used in three different forms:
346 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
347 for fast loading by a Just-In-Time compiler), and as a human readable
348 assembly language representation. This allows LLVM to provide a powerful
349 intermediate representation for efficient compiler transformations and
350 analysis, while providing a natural means to debug and visualize the
351 transformations. The three different forms of LLVM are all equivalent. This
352 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]354<p>The LLVM representation aims to be light-weight and low-level while being
355 expressive, typed, and extensible at the same time. It aims to be a
356 "universal IR" of sorts, by being at a low enough level that high-level ideas
357 may be cleanly mapped to it (similar to how microprocessors are "universal
358 IR's", allowing many source languages to be mapped to them). By providing
359 type information, LLVM can be used as the target of optimizations: for
360 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]361 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]362 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]364<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]365<h4>
366 <a name="wellformed">Well-Formedness</a>
367</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]368
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]369<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]371<p>It is important to note that this document describes 'well formed' LLVM
372 assembly language. There is a difference between what the parser accepts and
373 what is considered 'well formed'. For example, the following instruction is
374 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]375
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]376<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]377%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]378</pre>
379
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]380<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
381 LLVM infrastructure provides a verification pass that may be used to verify
382 that an LLVM module is well formed. This pass is automatically run by the
383 parser after parsing input assembly and by the optimizer before it outputs
384 bitcode. The violations pointed out by the verifier pass indicate bugs in
385 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]386
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]387</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]388
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]389</div>
390
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]391<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]392
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]393<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]394<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]395<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]396
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]397<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]398
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]399<p>LLVM identifiers come in two basic types: global and local. Global
400 identifiers (functions, global variables) begin with the <tt>'@'</tt>
401 character. Local identifiers (register names, types) begin with
402 the <tt>'%'</tt> character. Additionally, there are three different formats
403 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]404
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]405<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]406 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]407 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
408 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
409 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
410 other characters in their names can be surrounded with quotes. Special
411 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
412 ASCII code for the character in hexadecimal. In this way, any character
413 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]414
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]415 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]416 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]417
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]418 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]419 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]420</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]422<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]423 don't need to worry about name clashes with reserved words, and the set of
424 reserved words may be expanded in the future without penalty. Additionally,
425 unnamed identifiers allow a compiler to quickly come up with a temporary
426 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]427
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]428<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]429 languages. There are keywords for different opcodes
430 ('<tt><a href="#i_add">add</a></tt>',
431 '<tt><a href="#i_bitcast">bitcast</a></tt>',
432 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
433 ('<tt><a href="#t_void">void</a></tt>',
434 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
435 reserved words cannot conflict with variable names, because none of them
436 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]437
438<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]439 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]440
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]441<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]442
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]443<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]444%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]445</pre>
446
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]447<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]449<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]450%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]451</pre>
452
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]453<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]454
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]455<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]456%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
457%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]458%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459</pre>
460
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]461<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
462 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]464<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]466 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
468 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]469 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]470
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]471 <li>Unnamed temporaries are numbered sequentially</li>
472</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]473
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]474<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]475 demonstrating instructions, we will follow an instruction with a comment that
476 defines the type and name of value produced. Comments are shown in italic
477 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]478
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]479</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]480
481<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]482<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]483<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]484<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]485<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]486<h3>
487 <a name="modulestructure">Module Structure</a>
488</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]489
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]490<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]492<p>LLVM programs are composed of "Module"s, each of which is a translation unit
493 of the input programs. Each module consists of functions, global variables,
494 and symbol table entries. Modules may be combined together with the LLVM
495 linker, which merges function (and global variable) definitions, resolves
496 forward declarations, and merges symbol table entries. Here is an example of
497 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]498
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]499<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]500<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]501<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]502
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]503<i>; External declaration of the puts function</i>&nbsp;
504<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]505
506<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]507define i32 @main() { <i>; i32()* </i>&nbsp;
508 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
509 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]510
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]511 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
512 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
513 <a href="#i_ret">ret</a> i32 0&nbsp;
514}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]515
516<i>; Named metadata</i>
517!1 = metadata !{i32 41}
518!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]519</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]521<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]522 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]523 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]524 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
525 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]527<p>In general, a module is made up of a list of global values, where both
528 functions and global variables are global values. Global values are
529 represented by a pointer to a memory location (in this case, a pointer to an
530 array of char, and a pointer to a function), and have one of the
531 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]532
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]533</div>
534
535<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]536<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]537 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]538</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]539
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]540<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]541
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]542<p>All Global Variables and Functions have one of the following types of
543 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]544
545<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]547 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
548 by objects in the current module. In particular, linking code into a
549 module with an private global value may cause the private to be renamed as
550 necessary to avoid collisions. Because the symbol is private to the
551 module, all references can be updated. This doesn't show up in any symbol
552 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]553
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]555 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
556 assembler and evaluated by the linker. Unlike normal strong symbols, they
557 are removed by the linker from the final linked image (executable or
558 dynamic library).</dd>
559
560 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
561 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
562 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
563 linker. The symbols are removed by the linker from the final linked image
564 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]565
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]566 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
567 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
568 of the object is not taken. For instance, functions that had an inline
569 definition, but the compiler decided not to inline it. Note,
570 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
571 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
572 visibility. The symbols are removed by the linker from the final linked
573 image (executable or dynamic library).</dd>
574
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]575 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]576 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]577 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
578 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]579
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]581 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]582 into the object file corresponding to the LLVM module. They exist to
583 allow inlining and other optimizations to take place given knowledge of
584 the definition of the global, which is known to be somewhere outside the
585 module. Globals with <tt>available_externally</tt> linkage are allowed to
586 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
587 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]588
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]589 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]590 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]591 the same name when linkage occurs. This can be used to implement
592 some forms of inline functions, templates, or other code which must be
593 generated in each translation unit that uses it, but where the body may
594 be overridden with a more definitive definition later. Unreferenced
595 <tt>linkonce</tt> globals are allowed to be discarded. Note that
596 <tt>linkonce</tt> linkage does not actually allow the optimizer to
597 inline the body of this function into callers because it doesn't know if
598 this definition of the function is the definitive definition within the
599 program or whether it will be overridden by a stronger definition.
600 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
601 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]602
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]603 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]604 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
605 <tt>linkonce</tt> linkage, except that unreferenced globals with
606 <tt>weak</tt> linkage may not be discarded. This is used for globals that
607 are declared "weak" in C source code.</dd>
608
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]610 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
611 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
612 global scope.
613 Symbols with "<tt>common</tt>" linkage are merged in the same way as
614 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]615 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]616 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]617 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
618 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]619
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]620
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]621 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]622 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]623 pointer to array type. When two global variables with appending linkage
624 are linked together, the two global arrays are appended together. This is
625 the LLVM, typesafe, equivalent of having the system linker append together
626 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]627
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]628 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]629 <dd>The semantics of this linkage follow the ELF object file model: the symbol
630 is weak until linked, if not linked, the symbol becomes null instead of
631 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]632
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]633 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
634 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]635 <dd>Some languages allow differing globals to be merged, such as two functions
636 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]637 that only equivalent globals are ever merged (the "one definition rule"
638 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]639 and <tt>weak_odr</tt> linkage types to indicate that the global will only
640 be merged with equivalent globals. These linkage types are otherwise the
641 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]642
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]643 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]644 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]645 visible, meaning that it participates in linkage and can be used to
646 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]647</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]648
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]649<p>The next two types of linkage are targeted for Microsoft Windows platform
650 only. They are designed to support importing (exporting) symbols from (to)
651 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]653<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]654 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]655 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]656 or variable via a global pointer to a pointer that is set up by the DLL
657 exporting the symbol. On Microsoft Windows targets, the pointer name is
658 formed by combining <code>__imp_</code> and the function or variable
659 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]660
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]661 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]662 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]663 pointer to a pointer in a DLL, so that it can be referenced with the
664 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
665 name is formed by combining <code>__imp_</code> and the function or
666 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]667</dl>
668
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]669<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
670 another module defined a "<tt>.LC0</tt>" variable and was linked with this
671 one, one of the two would be renamed, preventing a collision. Since
672 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
673 declarations), they are accessible outside of the current module.</p>
674
675<p>It is illegal for a function <i>declaration</i> to have any linkage type
676 other than "externally visible", <tt>dllimport</tt>
677 or <tt>extern_weak</tt>.</p>
678
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]679<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]680 or <tt>weak_odr</tt> linkages.</p>
681
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]682</div>
683
684<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]685<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]686 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]687</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]688
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]689<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]690
691<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]692 and <a href="#i_invoke">invokes</a> can all have an optional calling
693 convention specified for the call. The calling convention of any pair of
694 dynamic caller/callee must match, or the behavior of the program is
695 undefined. The following calling conventions are supported by LLVM, and more
696 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]697
698<dl>
699 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]700 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]701 specified) matches the target C calling conventions. This calling
702 convention supports varargs function calls and tolerates some mismatch in
703 the declared prototype and implemented declaration of the function (as
704 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]705
706 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]708 (e.g. by passing things in registers). This calling convention allows the
709 target to use whatever tricks it wants to produce fast code for the
710 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]711 (Application Binary Interface).
712 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]713 when this or the GHC convention is used.</a> This calling convention
714 does not support varargs and requires the prototype of all callees to
715 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]716
717 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]718 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]719 as possible under the assumption that the call is not commonly executed.
720 As such, these calls often preserve all registers so that the call does
721 not break any live ranges in the caller side. This calling convention
722 does not support varargs and requires the prototype of all callees to
723 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]724
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]725 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
726 <dd>This calling convention has been implemented specifically for use by the
727 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
728 It passes everything in registers, going to extremes to achieve this by
729 disabling callee save registers. This calling convention should not be
730 used lightly but only for specific situations such as an alternative to
731 the <em>register pinning</em> performance technique often used when
732 implementing functional programming languages.At the moment only X86
733 supports this convention and it has the following limitations:
734 <ul>
735 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
736 floating point types are supported.</li>
737 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
738 6 floating point parameters.</li>
739 </ul>
740 This calling convention supports
741 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
742 requires both the caller and callee are using it.
743 </dd>
744
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]745 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]746 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]747 target-specific calling conventions to be used. Target specific calling
748 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]749</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]750
751<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]752 support Pascal conventions or any other well-known target-independent
753 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]754
755</div>
756
757<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]758<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]759 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]760</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]761
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]762<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]763
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]764<p>All Global Variables and Functions have one of the following visibility
765 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]766
767<dl>
768 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]769 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]770 that the declaration is visible to other modules and, in shared libraries,
771 means that the declared entity may be overridden. On Darwin, default
772 visibility means that the declaration is visible to other modules. Default
773 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]774
775 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]776 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]777 object if they are in the same shared object. Usually, hidden visibility
778 indicates that the symbol will not be placed into the dynamic symbol
779 table, so no other module (executable or shared library) can reference it
780 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]781
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]782 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]783 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]784 the dynamic symbol table, but that references within the defining module
785 will bind to the local symbol. That is, the symbol cannot be overridden by
786 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]787</dl>
788
789</div>
790
791<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]792<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]793 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]794</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]795
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]796<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]797
798<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]799 it easier to read the IR and make the IR more condensed (particularly when
800 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]801
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]802<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]803%mytype = type { %mytype*, i32 }
804</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]805
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]806<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]807 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]808 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]809
810<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]811 and that you can therefore specify multiple names for the same type. This
812 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
813 uses structural typing, the name is not part of the type. When printing out
814 LLVM IR, the printer will pick <em>one name</em> to render all types of a
815 particular shape. This means that if you have code where two different
816 source types end up having the same LLVM type, that the dumper will sometimes
817 print the "wrong" or unexpected type. This is an important design point and
818 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]819
820</div>
821
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]822<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]823<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]824 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]825</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]826
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]827<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]828
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]829<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]830 instead of run-time. Global variables may optionally be initialized, may
831 have an explicit section to be placed in, and may have an optional explicit
832 alignment specified. A variable may be defined as "thread_local", which
833 means that it will not be shared by threads (each thread will have a
834 separated copy of the variable). A variable may be defined as a global
835 "constant," which indicates that the contents of the variable
836 will <b>never</b> be modified (enabling better optimization, allowing the
837 global data to be placed in the read-only section of an executable, etc).
838 Note that variables that need runtime initialization cannot be marked
839 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]840
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]841<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
842 constant, even if the final definition of the global is not. This capability
843 can be used to enable slightly better optimization of the program, but
844 requires the language definition to guarantee that optimizations based on the
845 'constantness' are valid for the translation units that do not include the
846 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]847
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]848<p>As SSA values, global variables define pointer values that are in scope
849 (i.e. they dominate) all basic blocks in the program. Global variables
850 always define a pointer to their "content" type because they describe a
851 region of memory, and all memory objects in LLVM are accessed through
852 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]853
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]854<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
855 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]856 like this can be merged with other constants if they have the same
857 initializer. Note that a constant with significant address <em>can</em>
858 be merged with a <tt>unnamed_addr</tt> constant, the result being a
859 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]860
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]861<p>A global variable may be declared to reside in a target-specific numbered
862 address space. For targets that support them, address spaces may affect how
863 optimizations are performed and/or what target instructions are used to
864 access the variable. The default address space is zero. The address space
865 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]866
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]867<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]868 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]869
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]870<p>An explicit alignment may be specified for a global, which must be a power
871 of 2. If not present, or if the alignment is set to zero, the alignment of
872 the global is set by the target to whatever it feels convenient. If an
873 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]874 alignment. Targets and optimizers are not allowed to over-align the global
875 if the global has an assigned section. In this case, the extra alignment
876 could be observable: for example, code could assume that the globals are
877 densely packed in their section and try to iterate over them as an array,
878 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]879
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]880<p>For example, the following defines a global in a numbered address space with
881 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]882
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]883<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]884@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]885</pre>
886
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]887</div>
888
889
890<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]891<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]892 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]893</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]894
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]895<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]896
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]897<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]898 optional <a href="#linkage">linkage type</a>, an optional
899 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]900 <a href="#callingconv">calling convention</a>,
901 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]902 <a href="#paramattrs">parameter attribute</a> for the return type, a function
903 name, a (possibly empty) argument list (each with optional
904 <a href="#paramattrs">parameter attributes</a>), optional
905 <a href="#fnattrs">function attributes</a>, an optional section, an optional
906 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
907 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]908
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]909<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
910 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]911 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]912 <a href="#callingconv">calling convention</a>,
913 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]914 <a href="#paramattrs">parameter attribute</a> for the return type, a function
915 name, a possibly empty list of arguments, an optional alignment, and an
916 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]917
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]918<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]919 (Control Flow Graph) for the function. Each basic block may optionally start
920 with a label (giving the basic block a symbol table entry), contains a list
921 of instructions, and ends with a <a href="#terminators">terminator</a>
922 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]923
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]924<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]925 executed on entrance to the function, and it is not allowed to have
926 predecessor basic blocks (i.e. there can not be any branches to the entry
927 block of a function). Because the block can have no predecessors, it also
928 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]929
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]930<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]931 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]932
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]933<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]934 the alignment is set to zero, the alignment of the function is set by the
935 target to whatever it feels convenient. If an explicit alignment is
936 specified, the function is forced to have at least that much alignment. All
937 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]938
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]939<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
940 be significant and two identical functions can be merged</p>.
941
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]942<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]943<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]944define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]945 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
946 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
947 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
948 [<a href="#gc">gc</a>] { ... }
949</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]950
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]951</div>
952
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]953<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]954<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]955 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]956</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]957
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]958<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]959
960<p>Aliases act as "second name" for the aliasee value (which can be either
961 function, global variable, another alias or bitcast of global value). Aliases
962 may have an optional <a href="#linkage">linkage type</a>, and an
963 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]964
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]965<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]966<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]967@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]968</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]969
970</div>
971
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]972<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]973<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]974 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]975</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]976
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]977<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]978
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]979<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]980 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]981 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]982
983<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]984<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]985; Some unnamed metadata nodes, which are referenced by the named metadata.
986!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]987!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]988!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]989; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]990!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]991</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]992
993</div>
994
995<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]996<h3>
997 <a name="paramattrs">Parameter Attributes</a>
998</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]999
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1000<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1001
1002<p>The return type and each parameter of a function type may have a set of
1003 <i>parameter attributes</i> associated with them. Parameter attributes are
1004 used to communicate additional information about the result or parameters of
1005 a function. Parameter attributes are considered to be part of the function,
1006 not of the function type, so functions with different parameter attributes
1007 can have the same function type.</p>
1008
1009<p>Parameter attributes are simple keywords that follow the type specified. If
1010 multiple parameter attributes are needed, they are space separated. For
1011 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1012
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1013<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1014declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1015declare i32 @atoi(i8 zeroext)
1016declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1017</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1018
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1019<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1020 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1021
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1022<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1023
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1024<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1025 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1026 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1027 should be zero-extended to the extent required by the target's ABI (which
1028 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1029 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1030
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1033 should be sign-extended to the extent required by the target's ABI (which
1034 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1035 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1036
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1037 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This indicates that this parameter or return value should be treated in a
1039 special target-dependent fashion during while emitting code for a function
1040 call or return (usually, by putting it in a register as opposed to memory,
1041 though some targets use it to distinguish between two different kinds of
1042 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1043
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1044 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1045 <dd><p>This indicates that the pointer parameter should really be passed by
1046 value to the function. The attribute implies that a hidden copy of the
1047 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1048 is made between the caller and the callee, so the callee is unable to
1049 modify the value in the callee. This attribute is only valid on LLVM
1050 pointer arguments. It is generally used to pass structs and arrays by
1051 value, but is also valid on pointers to scalars. The copy is considered
1052 to belong to the caller not the callee (for example,
1053 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1054 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1055 values.</p>
1056
1057 <p>The byval attribute also supports specifying an alignment with
1058 the align attribute. It indicates the alignment of the stack slot to
1059 form and the known alignment of the pointer specified to the call site. If
1060 the alignment is not specified, then the code generator makes a
1061 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1062
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1063 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1064 <dd>This indicates that the pointer parameter specifies the address of a
1065 structure that is the return value of the function in the source program.
1066 This pointer must be guaranteed by the caller to be valid: loads and
1067 stores to the structure may be assumed by the callee to not to trap. This
1068 may only be applied to the first parameter. This is not a valid attribute
1069 for return values. </dd>
1070
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1071 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1072 <dd>This indicates that pointer values
1073 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1074 value do not alias pointer values which are not <i>based</i> on it,
1075 ignoring certain "irrelevant" dependencies.
1076 For a call to the parent function, dependencies between memory
1077 references from before or after the call and from those during the call
1078 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1079 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1080 The caller shares the responsibility with the callee for ensuring that
1081 these requirements are met.
1082 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1083 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1084<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1085 Note that this definition of <tt>noalias</tt> is intentionally
1086 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1087 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1088<br>
1089 For function return values, C99's <tt>restrict</tt> is not meaningful,
1090 while LLVM's <tt>noalias</tt> is.
1091 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1092
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1093 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1094 <dd>This indicates that the callee does not make any copies of the pointer
1095 that outlive the callee itself. This is not a valid attribute for return
1096 values.</dd>
1097
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1098 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This indicates that the pointer parameter can be excised using the
1100 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1101 attribute for return values.</dd>
1102</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1103
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1104</div>
1105
1106<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1107<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1108 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1109</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1110
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1111<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1112
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1113<p>Each function may specify a garbage collector name, which is simply a
1114 string:</p>
1115
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1116<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1117define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1118</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1119
1120<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1121 collector which will cause the compiler to alter its output in order to
1122 support the named garbage collection algorithm.</p>
1123
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1124</div>
1125
1126<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1127<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1128 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1129</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1130
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1131<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1132
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1133<p>Function attributes are set to communicate additional information about a
1134 function. Function attributes are considered to be part of the function, not
1135 of the function type, so functions with different parameter attributes can
1136 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1137
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1138<p>Function attributes are simple keywords that follow the type specified. If
1139 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1140
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1141<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1142define void @f() noinline { ... }
1143define void @f() alwaysinline { ... }
1144define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1145define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1146</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1147
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1148<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1149 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1150 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1151 the backend should forcibly align the stack pointer. Specify the
1152 desired alignment, which must be a power of two, in parentheses.
1153
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1154 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1155 <dd>This attribute indicates that the inliner should attempt to inline this
1156 function into callers whenever possible, ignoring any active inlining size
1157 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1158
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1159 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis6f12e292010-10-25 16:29:03 +0000[diff] [blame]1160 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis0076d202010-10-25 19:07:39 +0000[diff] [blame]1161 meaning the function can be patched and/or hooked even while it is
1162 loaded into memory. On x86, the function prologue will be preceded
1163 by six bytes of padding and will begin with a two-byte instruction.
1164 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1165 higher were compiled in this fashion.</dd>
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1166
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1167 <dt><tt><b>nonlazybind</b></tt></dt>
1168 <dd>This attribute suppresses lazy symbol binding for the function. This
1169 may make calls to the function faster, at the cost of extra program
1170 startup time if the function is not called during program startup.</dd>
1171
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1172 <dt><tt><b>inlinehint</b></tt></dt>
1173 <dd>This attribute indicates that the source code contained a hint that inlining
1174 this function is desirable (such as the "inline" keyword in C/C++). It
1175 is just a hint; it imposes no requirements on the inliner.</dd>
1176
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1177 <dt><tt><b>naked</b></tt></dt>
1178 <dd>This attribute disables prologue / epilogue emission for the function.
1179 This can have very system-specific consequences.</dd>
1180
1181 <dt><tt><b>noimplicitfloat</b></tt></dt>
1182 <dd>This attributes disables implicit floating point instructions.</dd>
1183
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1184 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1185 <dd>This attribute indicates that the inliner should never inline this
1186 function in any situation. This attribute may not be used together with
1187 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1188
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1189 <dt><tt><b>noredzone</b></tt></dt>
1190 <dd>This attribute indicates that the code generator should not use a red
1191 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1192
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1193 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1194 <dd>This function attribute indicates that the function never returns
1195 normally. This produces undefined behavior at runtime if the function
1196 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1197
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This function attribute indicates that the function never returns with an
1200 unwind or exceptional control flow. If the function does unwind, its
1201 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1202
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1203 <dt><tt><b>optsize</b></tt></dt>
1204 <dd>This attribute suggests that optimization passes and code generator passes
1205 make choices that keep the code size of this function low, and otherwise
1206 do optimizations specifically to reduce code size.</dd>
1207
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1208 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1209 <dd>This attribute indicates that the function computes its result (or decides
1210 to unwind an exception) based strictly on its arguments, without
1211 dereferencing any pointer arguments or otherwise accessing any mutable
1212 state (e.g. memory, control registers, etc) visible to caller functions.
1213 It does not write through any pointer arguments
1214 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1215 changes any state visible to callers. This means that it cannot unwind
1216 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1217 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1218
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1219 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1220 <dd>This attribute indicates that the function does not write through any
1221 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1222 arguments) or otherwise modify any state (e.g. memory, control registers,
1223 etc) visible to caller functions. It may dereference pointer arguments
1224 and read state that may be set in the caller. A readonly function always
1225 returns the same value (or unwinds an exception identically) when called
1226 with the same set of arguments and global state. It cannot unwind an
1227 exception by calling the <tt>C++</tt> exception throwing methods, but may
1228 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1229
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1230 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1231 <dd>This attribute indicates that the function should emit a stack smashing
1232 protector. It is in the form of a "canary"&mdash;a random value placed on
1233 the stack before the local variables that's checked upon return from the
1234 function to see if it has been overwritten. A heuristic is used to
1235 determine if a function needs stack protectors or not.<br>
1236<br>
1237 If a function that has an <tt>ssp</tt> attribute is inlined into a
1238 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1239 function will have an <tt>ssp</tt> attribute.</dd>
1240
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1241 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1242 <dd>This attribute indicates that the function should <em>always</em> emit a
1243 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1244 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1245<br>
1246 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1247 function that doesn't have an <tt>sspreq</tt> attribute or which has
1248 an <tt>ssp</tt> attribute, then the resulting function will have
1249 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindolafbff0ec2011-07-25 15:27:59 +0000[diff] [blame^]1250
1251 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1252 <dd>This attribute indicates that the ABI being targeted requires that
1253 an unwind table entry be produce for this function even if we can
1254 show that no exceptions passes by it. This is normally the case for
1255 the ELF x86-64 abi, but it can be disabled for some compilation
1256 units.</dd>
1257
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1258</dl>
1259
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1260</div>
1261
1262<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1263<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1264 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1265</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1266
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1267<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1268
1269<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1270 the GCC "file scope inline asm" blocks. These blocks are internally
1271 concatenated by LLVM and treated as a single unit, but may be separated in
1272 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1273
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1274<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1275module asm "inline asm code goes here"
1276module asm "more can go here"
1277</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1278
1279<p>The strings can contain any character by escaping non-printable characters.
1280 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1281 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1282
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1283<p>The inline asm code is simply printed to the machine code .s file when
1284 assembly code is generated.</p>
1285
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1286</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1287
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1288<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1289<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1290 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1291</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1292
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1293<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1294
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1295<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1296 data is to be laid out in memory. The syntax for the data layout is
1297 simply:</p>
1298
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1299<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1300target datalayout = "<i>layout specification</i>"
1301</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1302
1303<p>The <i>layout specification</i> consists of a list of specifications
1304 separated by the minus sign character ('-'). Each specification starts with
1305 a letter and may include other information after the letter to define some
1306 aspect of the data layout. The specifications accepted are as follows:</p>
1307
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1308<dl>
1309 <dt><tt>E</tt></dt>
1310 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1311 bits with the most significance have the lowest address location.</dd>
1312
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1313 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1314 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1315 the bits with the least significance have the lowest address
1316 location.</dd>
1317
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1318 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1319 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1320 <i>preferred</i> alignments. All sizes are in bits. Specifying
1321 the <i>pref</i> alignment is optional. If omitted, the
1322 preceding <tt>:</tt> should be omitted too.</dd>
1323
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1324 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1325 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1326 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1327
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1328 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1329 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1330 <i>size</i>.</dd>
1331
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1332 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1333 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1334 <i>size</i>. Only values of <i>size</i> that are supported by the target
1335 will work. 32 (float) and 64 (double) are supported on all targets;
1336 80 or 128 (different flavors of long double) are also supported on some
1337 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1338
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1339 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1340 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1341 <i>size</i>.</dd>
1342
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1343 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1344 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1345 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1346
1347 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1348 <dd>This specifies a set of native integer widths for the target CPU
1349 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1350 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1351 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1352 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1353</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1354
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1355<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1356 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1357 specifications in the <tt>datalayout</tt> keyword. The default specifications
1358 are given in this list:</p>
1359
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1360<ul>
1361 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1362 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1363 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1364 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1365 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1366 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1367 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1368 alignment of 64-bits</li>
1369 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1370 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1371 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1372 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1373 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1374 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1375</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1376
1377<p>When LLVM is determining the alignment for a given type, it uses the
1378 following rules:</p>
1379
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1380<ol>
1381 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1382 specification is used.</li>
1383
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1384 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1385 smallest integer type that is larger than the bitwidth of the sought type
1386 is used. If none of the specifications are larger than the bitwidth then
1387 the the largest integer type is used. For example, given the default
1388 specifications above, the i7 type will use the alignment of i8 (next
1389 largest) while both i65 and i256 will use the alignment of i64 (largest
1390 specified).</li>
1391
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1392 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1393 largest vector type that is smaller than the sought vector type will be
1394 used as a fall back. This happens because &lt;128 x double&gt; can be
1395 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1396</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1397
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1398</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1399
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1400<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1401<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1402 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1403</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1404
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1405<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1406
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1407<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1408with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1409is undefined. Pointer values are associated with address ranges
1410according to the following rules:</p>
1411
1412<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1413 <li>A pointer value is associated with the addresses associated with
1414 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1415 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1416 range of the variable's storage.</li>
1417 <li>The result value of an allocation instruction is associated with
1418 the address range of the allocated storage.</li>
1419 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1420 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1421 <li>An integer constant other than zero or a pointer value returned
1422 from a function not defined within LLVM may be associated with address
1423 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1424 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1425 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1426</ul>
1427
1428<p>A pointer value is <i>based</i> on another pointer value according
1429 to the following rules:</p>
1430
1431<ul>
1432 <li>A pointer value formed from a
1433 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1434 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1435 <li>The result value of a
1436 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1437 of the <tt>bitcast</tt>.</li>
1438 <li>A pointer value formed by an
1439 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1440 pointer values that contribute (directly or indirectly) to the
1441 computation of the pointer's value.</li>
1442 <li>The "<i>based</i> on" relationship is transitive.</li>
1443</ul>
1444
1445<p>Note that this definition of <i>"based"</i> is intentionally
1446 similar to the definition of <i>"based"</i> in C99, though it is
1447 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1448
1449<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1450<tt><a href="#i_load">load</a></tt> merely indicates the size and
1451alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1452interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1453<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1454and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1455
1456<p>Consequently, type-based alias analysis, aka TBAA, aka
1457<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1458LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1459additional information which specialized optimization passes may use
1460to implement type-based alias analysis.</p>
1461
1462</div>
1463
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1464<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1465<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1466 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1467</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1468
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1469<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1470
1471<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1472href="#i_store"><tt>store</tt></a>s, and <a
1473href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1474The optimizers must not change the number of volatile operations or change their
1475order of execution relative to other volatile operations. The optimizers
1476<i>may</i> change the order of volatile operations relative to non-volatile
1477operations. This is not Java's "volatile" and has no cross-thread
1478synchronization behavior.</p>
1479
1480</div>
1481
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1482<!-- ======================================================================= -->
1483<h3>
1484 <a name="memmodel">Memory Model for Concurrent Operations</a>
1485</h3>
1486
1487<div>
1488
1489<p>The LLVM IR does not define any way to start parallel threads of execution
1490or to register signal handlers. Nonetheless, there are platform-specific
1491ways to create them, and we define LLVM IR's behavior in their presence. This
1492model is inspired by the C++0x memory model.</p>
1493
1494<p>We define a <i>happens-before</i> partial order as the least partial order
1495that</p>
1496<ul>
1497 <li>Is a superset of single-thread program order, and</li>
1498 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1499 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1500 by platform-specific techniques, like pthread locks, thread
1501 creation, thread joining, etc., and by the atomic operations described
1502 in the <a href="#int_atomics">Atomic intrinsics</a> section.</li>
1503</ul>
1504
1505<p>Note that program order does not introduce <i>happens-before</i> edges
1506between a thread and signals executing inside that thread.</p>
1507
1508<p>Every (defined) read operation (load instructions, memcpy, atomic
1509loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1510(defined) write operations (store instructions, atomic
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1511stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1512initialized globals are considered to have a write of the initializer which is
1513atomic and happens before any other read or write of the memory in question.
1514For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1515any write to the same byte, except:</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1516
1517<ul>
1518 <li>If <var>write<sub>1</sub></var> happens before
1519 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1520 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1521 does not see <var>write<sub>1</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1522 <li>If <var>R<sub>byte</sub></var> happens before <var>write<sub>3</var>,
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1523 then <var>R<sub>byte</sub></var> does not see
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1524 <var>write<sub>3</sub></var>.
1525</ul>
1526
1527<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1528<ul>
1529 <li>If there is no write to the same byte that happens before
1530 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1531 <tt>undef</tt> for that byte.
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1532 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1533 <var>R<sub>byte</sub></var> returns the value written by that
1534 write.</li>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1535 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1536 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
1537 values written. See the <a href="#int_atomics">Atomic intrinsics</a>
1538 section for additional guarantees on how the choice is made.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1539 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1540</ul>
1541
1542<p><var>R</var> returns the value composed of the series of bytes it read.
1543This implies that some bytes within the value may be <tt>undef</tt>
1544<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1545defines the semantics of the operation; it doesn't mean that targets will
1546emit more than one instruction to read the series of bytes.</p>
1547
1548<p>Note that in cases where none of the atomic intrinsics are used, this model
1549places only one restriction on IR transformations on top of what is required
1550for single-threaded execution: introducing a store to a byte which might not
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1551otherwise be stored to can introduce undefined behavior. (Specifically, in
1552the case where another thread might write to and read from an address,
1553introducing a store can change a load that may see exactly one write into
1554a load that may see multiple writes.)</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1555
1556<!-- FIXME: This model assumes all targets where concurrency is relevant have
1557a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1558none of the backends currently in the tree fall into this category; however,
1559there might be targets which care. If there are, we want a paragraph
1560like the following:
1561
1562Targets may specify that stores narrower than a certain width are not
1563available; on such a target, for the purposes of this model, treat any
1564non-atomic write with an alignment or width less than the minimum width
1565as if it writes to the relevant surrounding bytes.
1566-->
1567
1568</div>
1569
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1570</div>
1571
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1572<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1573<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1574<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1575
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1576<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1577
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1578<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1579 intermediate representation. Being typed enables a number of optimizations
1580 to be performed on the intermediate representation directly, without having
1581 to do extra analyses on the side before the transformation. A strong type
1582 system makes it easier to read the generated code and enables novel analyses
1583 and transformations that are not feasible to perform on normal three address
1584 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1585
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1586<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1587<h3>
1588 <a name="t_classifications">Type Classifications</a>
1589</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1590
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1591<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1592
1593<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1594
1595<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1596 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1597 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1598 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1599 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1600 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1601 </tr>
1602 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1603 <td><a href="#t_floating">floating point</a></td>
1604 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1605 </tr>
1606 <tr>
1607 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1608 <td><a href="#t_integer">integer</a>,
1609 <a href="#t_floating">floating point</a>,
1610 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1611 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1612 <a href="#t_struct">structure</a>,
1613 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1614 <a href="#t_label">label</a>,
1615 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1616 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1617 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1618 <tr>
1619 <td><a href="#t_primitive">primitive</a></td>
1620 <td><a href="#t_label">label</a>,
1621 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1622 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1623 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1624 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1625 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1626 </tr>
1627 <tr>
1628 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1629 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1630 <a href="#t_function">function</a>,
1631 <a href="#t_pointer">pointer</a>,
1632 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1633 <a href="#t_vector">vector</a>,
1634 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1635 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1636 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1637 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1638</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1639
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1640<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1641 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1642 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1643
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1644</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1645
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1646<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1647<h3>
1648 <a name="t_primitive">Primitive Types</a>
1649</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1650
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1651<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1652
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1653<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1654 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1655
1656<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1657<h4>
1658 <a name="t_integer">Integer Type</a>
1659</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1660
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1661<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1662
1663<h5>Overview:</h5>
1664<p>The integer type is a very simple type that simply specifies an arbitrary
1665 bit width for the integer type desired. Any bit width from 1 bit to
1666 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1667
1668<h5>Syntax:</h5>
1669<pre>
1670 iN
1671</pre>
1672
1673<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1674 value.</p>
1675
1676<h5>Examples:</h5>
1677<table class="layout">
1678 <tr class="layout">
1679 <td class="left"><tt>i1</tt></td>
1680 <td class="left">a single-bit integer.</td>
1681 </tr>
1682 <tr class="layout">
1683 <td class="left"><tt>i32</tt></td>
1684 <td class="left">a 32-bit integer.</td>
1685 </tr>
1686 <tr class="layout">
1687 <td class="left"><tt>i1942652</tt></td>
1688 <td class="left">a really big integer of over 1 million bits.</td>
1689 </tr>
1690</table>
1691
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1692</div>
1693
1694<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1695<h4>
1696 <a name="t_floating">Floating Point Types</a>
1697</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1698
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1699<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1700
1701<table>
1702 <tbody>
1703 <tr><th>Type</th><th>Description</th></tr>
1704 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1705 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1706 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1707 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1708 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1709 </tbody>
1710</table>
1711
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1712</div>
1713
1714<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1715<h4>
1716 <a name="t_x86mmx">X86mmx Type</a>
1717</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1718
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1719<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1720
1721<h5>Overview:</h5>
1722<p>The x86mmx type represents a value held in an MMX register on an x86 machine. The operations allowed on it are quite limited: parameters and return values, load and store, and bitcast. User-specified MMX instructions are represented as intrinsic or asm calls with arguments and/or results of this type. There are no arrays, vectors or constants of this type.</p>
1723
1724<h5>Syntax:</h5>
1725<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1726 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1727</pre>
1728
1729</div>
1730
1731<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1732<h4>
1733 <a name="t_void">Void Type</a>
1734</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1735
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1736<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1737
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1738<h5>Overview:</h5>
1739<p>The void type does not represent any value and has no size.</p>
1740
1741<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1742<pre>
1743 void
1744</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1745
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1746</div>
1747
1748<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1749<h4>
1750 <a name="t_label">Label Type</a>
1751</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1752
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1753<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1754
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1755<h5>Overview:</h5>
1756<p>The label type represents code labels.</p>
1757
1758<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1759<pre>
1760 label
1761</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1762
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1763</div>
1764
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1765<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1766<h4>
1767 <a name="t_metadata">Metadata Type</a>
1768</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1769
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1770<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1771
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1772<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1773<p>The metadata type represents embedded metadata. No derived types may be
1774 created from metadata except for <a href="#t_function">function</a>
1775 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1776
1777<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1778<pre>
1779 metadata
1780</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1781
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1782</div>
1783
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1784</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1785
1786<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1787<h3>
1788 <a name="t_derived">Derived Types</a>
1789</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1790
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1791<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1792
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1793<p>The real power in LLVM comes from the derived types in the system. This is
1794 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1795 useful types. Each of these types contain one or more element types which
1796 may be a primitive type, or another derived type. For example, it is
1797 possible to have a two dimensional array, using an array as the element type
1798 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1799
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1800</div>
1801
1802
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1803<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1804<h4>
1805 <a name="t_aggregate">Aggregate Types</a>
1806</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1807
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1808<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1809
1810<p>Aggregate Types are a subset of derived types that can contain multiple
1811 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1812 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1813 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1814
1815</div>
1816
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1817<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1818<h4>
1819 <a name="t_array">Array Type</a>
1820</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1821
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1822<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1823
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1824<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1825<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1826 sequentially in memory. The array type requires a size (number of elements)
1827 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1828
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1829<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1830<pre>
1831 [&lt;# elements&gt; x &lt;elementtype&gt;]
1832</pre>
1833
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1834<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1835 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1836
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1837<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1838<table class="layout">
1839 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1840 <td class="left"><tt>[40 x i32]</tt></td>
1841 <td class="left">Array of 40 32-bit integer values.</td>
1842 </tr>
1843 <tr class="layout">
1844 <td class="left"><tt>[41 x i32]</tt></td>
1845 <td class="left">Array of 41 32-bit integer values.</td>
1846 </tr>
1847 <tr class="layout">
1848 <td class="left"><tt>[4 x i8]</tt></td>
1849 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1850 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1851</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1852<p>Here are some examples of multidimensional arrays:</p>
1853<table class="layout">
1854 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1855 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1856 <td class="left">3x4 array of 32-bit integer values.</td>
1857 </tr>
1858 <tr class="layout">
1859 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1860 <td class="left">12x10 array of single precision floating point values.</td>
1861 </tr>
1862 <tr class="layout">
1863 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1864 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1865 </tr>
1866</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1867
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1868<p>There is no restriction on indexing beyond the end of the array implied by
1869 a static type (though there are restrictions on indexing beyond the bounds
1870 of an allocated object in some cases). This means that single-dimension
1871 'variable sized array' addressing can be implemented in LLVM with a zero
1872 length array type. An implementation of 'pascal style arrays' in LLVM could
1873 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1874
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1875</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1876
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1877<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1878<h4>
1879 <a name="t_function">Function Type</a>
1880</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1881
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1882<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1883
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1884<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1885<p>The function type can be thought of as a function signature. It consists of
1886 a return type and a list of formal parameter types. The return type of a
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1887 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1888
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1889<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1890<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1891 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1892</pre>
1893
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1894<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1895 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1896 which indicates that the function takes a variable number of arguments.
1897 Variable argument functions can access their arguments with
1898 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1899 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1900 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1901
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1902<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1903<table class="layout">
1904 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1905 <td class="left"><tt>i32 (i32)</tt></td>
1906 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1907 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1908 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1909 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1910 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1911 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1912 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1913 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1914 </td>
1915 </tr><tr class="layout">
1916 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1917 <td class="left">A vararg function that takes at least one
1918 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1919 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1920 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1921 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1922 </tr><tr class="layout">
1923 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1924 <td class="left">A function taking an <tt>i32</tt>, returning a
1925 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1926 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1927 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1928</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1929
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1930</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1931
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1932<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1933<h4>
1934 <a name="t_struct">Structure Type</a>
1935</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1936
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1937<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1938
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1939<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1940<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1941 in memory. The elements of a structure may be any type that has a size.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1942
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1943<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1944 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1945 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1946 Structures in registers are accessed using the
1947 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1948 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1949
1950<p>Structures may optionally be "packed" structures, which indicate that the
1951 alignment of the struct is one byte, and that there is no padding between
1952 the elements. In non-packed structs, padding between field types is defined
1953 by the target data string to match the underlying processor.</p>
1954
1955<p>Structures can either be "anonymous" or "named". An anonymous structure is
1956 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
1957 are always defined at the top level with a name. Anonmyous types are uniqued
1958 by their contents and can never be recursive since there is no way to write
1959 one. Named types can be recursive.
1960</p>
1961
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1962<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1963<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1964 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
1965 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1966</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1967
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1968<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1969<table class="layout">
1970 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1971 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1972 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1973 </tr>
1974 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1975 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1976 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1977 second element is a <a href="#t_pointer">pointer</a> to a
1978 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1979 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1980 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1981 <tr class="layout">
1982 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
1983 <td class="left">A packed struct known to be 5 bytes in size.</td>
1984 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1985</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1986
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1987</div>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1988
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1989<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1990<h4>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]1991 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1992</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1993
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1994<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1995
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1996<h5>Overview:</h5>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]1997<p>Opaque structure types are used to represent named structure types that do
1998 not have a body specified. This corresponds (for example) to the C notion of
1999 a forward declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2000
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2001<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2002<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2003 %X = type opaque
2004 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2005</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2006
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2007<h5>Examples:</h5>
2008<table class="layout">
2009 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2010 <td class="left"><tt>opaque</tt></td>
2011 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2012 </tr>
2013</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2014
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2015</div>
2016
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2017
2018
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2019<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2020<h4>
2021 <a name="t_pointer">Pointer Type</a>
2022</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2023
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2024<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2025
2026<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]2027<p>The pointer type is used to specify memory locations.
2028 Pointers are commonly used to reference objects in memory.</p>
2029
2030<p>Pointer types may have an optional address space attribute defining the
2031 numbered address space where the pointed-to object resides. The default
2032 address space is number zero. The semantics of non-zero address
2033 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2034
2035<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2036 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2037
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2038<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2039<pre>
2040 &lt;type&gt; *
2041</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2042
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2043<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2044<table class="layout">
2045 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2046 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2047 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2048 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2049 </tr>
2050 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]2051 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2052 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2053 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2054 <tt>i32</tt>.</td>
2055 </tr>
2056 <tr class="layout">
2057 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2058 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2059 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2060 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2061</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2062
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2063</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2064
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2065<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2066<h4>
2067 <a name="t_vector">Vector Type</a>
2068</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2069
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2070<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2071
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2072<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2073<p>A vector type is a simple derived type that represents a vector of elements.
2074 Vector types are used when multiple primitive data are operated in parallel
2075 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]2076 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2077 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2078
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2079<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2080<pre>
2081 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2082</pre>
2083
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]2084<p>The number of elements is a constant integer value larger than 0; elementtype
2085 may be any integer or floating point type. Vectors of size zero are not
2086 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2087
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2088<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2089<table class="layout">
2090 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2091 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2092 <td class="left">Vector of 4 32-bit integer values.</td>
2093 </tr>
2094 <tr class="layout">
2095 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2096 <td class="left">Vector of 8 32-bit floating-point values.</td>
2097 </tr>
2098 <tr class="layout">
2099 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2100 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2101 </tr>
2102</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2103
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2104</div>
2105
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2106<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2107<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2108<!-- *********************************************************************** -->
2109
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2110<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2111
2112<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2113 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2114
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2115<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2116<h3>
2117 <a name="simpleconstants">Simple Constants</a>
2118</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2119
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2120<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2121
2122<dl>
2123 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2124 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2125 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2126
2127 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2128 <dd>Standard integers (such as '4') are constants of
2129 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2130 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2131
2132 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2133 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2134 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2135 notation (see below). The assembler requires the exact decimal value of a
2136 floating-point constant. For example, the assembler accepts 1.25 but
2137 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2138 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2139
2140 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2141 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2142 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2143</dl>
2144
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2145<p>The one non-intuitive notation for constants is the hexadecimal form of
2146 floating point constants. For example, the form '<tt>double
2147 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2148 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2149 constants are required (and the only time that they are generated by the
2150 disassembler) is when a floating point constant must be emitted but it cannot
2151 be represented as a decimal floating point number in a reasonable number of
2152 digits. For example, NaN's, infinities, and other special values are
2153 represented in their IEEE hexadecimal format so that assembly and disassembly
2154 do not cause any bits to change in the constants.</p>
2155
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2156<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2157 represented using the 16-digit form shown above (which matches the IEEE754
2158 representation for double); float values must, however, be exactly
2159 representable as IEE754 single precision. Hexadecimal format is always used
2160 for long double, and there are three forms of long double. The 80-bit format
2161 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2162 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2163 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2164 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2165 currently supported target uses this format. Long doubles will only work if
2166 they match the long double format on your target. All hexadecimal formats
2167 are big-endian (sign bit at the left).</p>
2168
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2169<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2170</div>
2171
2172<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2173<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2174<a name="aggregateconstants"></a> <!-- old anchor -->
2175<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2176</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2177
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2178<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2179
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2180<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2181 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2182
2183<dl>
2184 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2185 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2186 type definitions (a comma separated list of elements, surrounded by braces
2187 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2188 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2189 Structure constants must have <a href="#t_struct">structure type</a>, and
2190 the number and types of elements must match those specified by the
2191 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2192
2193 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2194 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2195 definitions (a comma separated list of elements, surrounded by square
2196 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2197 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2198 the number and types of elements must match those specified by the
2199 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2200
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2201 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2202 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2203 definitions (a comma separated list of elements, surrounded by
2204 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2205 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2206 have <a href="#t_vector">vector type</a>, and the number and types of
2207 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2208
2209 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2210 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2211 value to zero of <em>any</em> type, including scalar and
2212 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2213 This is often used to avoid having to print large zero initializers
2214 (e.g. for large arrays) and is always exactly equivalent to using explicit
2215 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2216
2217 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2218 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2219 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2220 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2221 be interpreted as part of the instruction stream, metadata is a place to
2222 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2223</dl>
2224
2225</div>
2226
2227<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2228<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2229 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2230</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2231
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2232<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2233
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2234<p>The addresses of <a href="#globalvars">global variables</a>
2235 and <a href="#functionstructure">functions</a> are always implicitly valid
2236 (link-time) constants. These constants are explicitly referenced when
2237 the <a href="#identifiers">identifier for the global</a> is used and always
2238 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2239 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2240
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2241<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2242@X = global i32 17
2243@Y = global i32 42
2244@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2245</pre>
2246
2247</div>
2248
2249<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2250<h3>
2251 <a name="undefvalues">Undefined Values</a>
2252</h3>
2253
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2254<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2255
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2256<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2257 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2258 Undefined values may be of any type (other than '<tt>label</tt>'
2259 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2260
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2261<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2262 program is well defined no matter what value is used. This gives the
2263 compiler more freedom to optimize. Here are some examples of (potentially
2264 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2265
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2266
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2267<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2268 %A = add %X, undef
2269 %B = sub %X, undef
2270 %C = xor %X, undef
2271Safe:
2272 %A = undef
2273 %B = undef
2274 %C = undef
2275</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2276
2277<p>This is safe because all of the output bits are affected by the undef bits.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2278 Any output bit can have a zero or one depending on the input bits.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2279
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2280<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2281 %A = or %X, undef
2282 %B = and %X, undef
2283Safe:
2284 %A = -1
2285 %B = 0
2286Unsafe:
2287 %A = undef
2288 %B = undef
2289</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2290
2291<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2292 For example, if <tt>%X</tt> has a zero bit, then the output of the
2293 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2294 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2295 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2296 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2297 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2298 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2299 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2300
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2301<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2302 %A = select undef, %X, %Y
2303 %B = select undef, 42, %Y
2304 %C = select %X, %Y, undef
2305Safe:
2306 %A = %X (or %Y)
2307 %B = 42 (or %Y)
2308 %C = %Y
2309Unsafe:
2310 %A = undef
2311 %B = undef
2312 %C = undef
2313</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2314
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2315<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2316 branch) conditions can go <em>either way</em>, but they have to come from one
2317 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2318 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2319 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2320 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2321 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2322 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2323
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2324<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2325 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2326
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2327 %B = undef
2328 %C = xor %B, %B
2329
2330 %D = undef
2331 %E = icmp lt %D, 4
2332 %F = icmp gte %D, 4
2333
2334Safe:
2335 %A = undef
2336 %B = undef
2337 %C = undef
2338 %D = undef
2339 %E = undef
2340 %F = undef
2341</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2342
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2343<p>This example points out that two '<tt>undef</tt>' operands are not
2344 necessarily the same. This can be surprising to people (and also matches C
2345 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2346 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2347 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2348 its value over its "live range". This is true because the variable doesn't
2349 actually <em>have a live range</em>. Instead, the value is logically read
2350 from arbitrary registers that happen to be around when needed, so the value
2351 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2352 need to have the same semantics or the core LLVM "replace all uses with"
2353 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2354
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2355<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2356 %A = fdiv undef, %X
2357 %B = fdiv %X, undef
2358Safe:
2359 %A = undef
2360b: unreachable
2361</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2362
2363<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2364 value</em> and <em>undefined behavior</em>. An undefined value (like
2365 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2366 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2367 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2368 defined on SNaN's. However, in the second example, we can make a more
2369 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2370 arbitrary value, we are allowed to assume that it could be zero. Since a
2371 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2372 the operation does not execute at all. This allows us to delete the divide and
2373 all code after it. Because the undefined operation "can't happen", the
2374 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2375
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2376<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2377a: store undef -> %X
2378b: store %X -> undef
2379Safe:
2380a: &lt;deleted&gt;
2381b: unreachable
2382</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2383
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2384<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2385 undefined value can be assumed to not have any effect; we can assume that the
2386 value is overwritten with bits that happen to match what was already there.
2387 However, a store <em>to</em> an undefined location could clobber arbitrary
2388 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2389
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2390</div>
2391
2392<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2393<h3>
2394 <a name="trapvalues">Trap Values</a>
2395</h3>
2396
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2397<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2398
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2399<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2400 instead of representing an unspecified bit pattern, they represent the
2401 fact that an instruction or constant expression which cannot evoke side
2402 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2403 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2404
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2405<p>There is currently no way of representing a trap value in the IR; they
Dan Gohman855abed2010-05-03 14:51:43 +0000[diff] [blame]2406 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2407 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag.</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2408
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2409<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2410
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2411<ul>
2412<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2413 their operands.</li>
2414
2415<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2416 to their dynamic predecessor basic block.</li>
2417
2418<li>Function arguments depend on the corresponding actual argument values in
2419 the dynamic callers of their functions.</li>
2420
2421<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2422 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2423 control back to them.</li>
2424
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2425<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2426 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2427 or exception-throwing call instructions that dynamically transfer control
2428 back to them.</li>
2429
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2430<li>Non-volatile loads and stores depend on the most recent stores to all of the
2431 referenced memory addresses, following the order in the IR
2432 (including loads and stores implied by intrinsics such as
2433 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2434
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2435<!-- TODO: In the case of multiple threads, this only applies if the store
2436 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2437
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2438<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2439
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2440<li>An instruction with externally visible side effects depends on the most
2441 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2442 the order in the IR. (This includes
2443 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2444
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2445<li>An instruction <i>control-depends</i> on a
2446 <a href="#terminators">terminator instruction</a>
2447 if the terminator instruction has multiple successors and the instruction
2448 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2449 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2450
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2451<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2452 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2453 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2454 successor.</li>
2455
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2456<li>Dependence is transitive.</li>
2457
2458</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2459
2460<p>Whenever a trap value is generated, all values which depend on it evaluate
2461 to trap. If they have side effects, the evoke their side effects as if each
2462 operand with a trap value were undef. If they have externally-visible side
2463 effects, the behavior is undefined.</p>
2464
2465<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2466
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2467<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2468entry:
2469 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2470 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2471 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2472 store i32 0, i32* %trap_yet_again ; undefined behavior
2473
2474 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2475 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2476
2477 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2478
2479 %narrowaddr = bitcast i32* @g to i16*
2480 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2481 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2482 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2483
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2484 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2485 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2486
2487true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2488 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2489 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2490 br label %end
2491
2492end:
2493 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2494 ; Both edges into this PHI are
2495 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2496 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2497
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2498 volatile store i32 0, i32* @g ; This would depend on the store in %true
2499 ; if %cmp is true, or the store in %entry
2500 ; otherwise, so this is undefined behavior.
2501
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2502 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2503 ; The same branch again, but this time the
2504 ; true block doesn't have side effects.
2505
2506second_true:
2507 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2508 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2509
2510second_end:
2511 volatile store i32 0, i32* @g ; This time, the instruction always depends
2512 ; on the store in %end. Also, it is
2513 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2514 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2515 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2516</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2517
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2518</div>
2519
2520<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2521<h3>
2522 <a name="blockaddress">Addresses of Basic Blocks</a>
2523</h3>
2524
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2525<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2526
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2527<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2528
2529<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2530 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2531 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2532
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2533<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2534 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2535 comparisons against null. Pointer equality tests between labels addresses
2536 results in undefined behavior &mdash; though, again, comparison against null
2537 is ok, and no label is equal to the null pointer. This may be passed around
2538 as an opaque pointer sized value as long as the bits are not inspected. This
2539 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2540 long as the original value is reconstituted before the <tt>indirectbr</tt>
2541 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2542
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2543<p>Finally, some targets may provide defined semantics when using the value as
2544 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2545
2546</div>
2547
2548
2549<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2550<h3>
2551 <a name="constantexprs">Constant Expressions</a>
2552</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2553
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2554<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2555
2556<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2557 to be used as constants. Constant expressions may be of
2558 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2559 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2560 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2561
2562<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2563 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2564 <dd>Truncate a constant to another type. The bit size of CST must be larger
2565 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2566
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2567 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2568 <dd>Zero extend a constant to another type. The bit size of CST must be
Duncan Sands28afd432010-07-13 12:06:14 +0000[diff] [blame]2569 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2570
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2571 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2572 <dd>Sign extend a constant to another type. The bit size of CST must be
Duncan Sands28afd432010-07-13 12:06:14 +0000[diff] [blame]2573 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2574
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2575 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2576 <dd>Truncate a floating point constant to another floating point type. The
2577 size of CST must be larger than the size of TYPE. Both types must be
2578 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2579
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2580 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2581 <dd>Floating point extend a constant to another type. The size of CST must be
2582 smaller or equal to the size of TYPE. Both types must be floating
2583 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2584
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2585 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2586 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2587 constant. TYPE must be a scalar or vector integer type. CST must be of
2588 scalar or vector floating point type. Both CST and TYPE must be scalars,
2589 or vectors of the same number of elements. If the value won't fit in the
2590 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2591
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2592 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2593 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2594 constant. TYPE must be a scalar or vector integer type. CST must be of
2595 scalar or vector floating point type. Both CST and TYPE must be scalars,
2596 or vectors of the same number of elements. If the value won't fit in the
2597 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2598
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2599 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2600 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2601 constant. TYPE must be a scalar or vector floating point type. CST must be
2602 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2603 vectors of the same number of elements. If the value won't fit in the
2604 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2605
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2606 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2607 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2608 constant. TYPE must be a scalar or vector floating point type. CST must be
2609 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2610 vectors of the same number of elements. If the value won't fit in the
2611 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2612
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2613 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2614 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2615 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2616 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2617 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2618
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2619 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2620 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2621 type. CST must be of integer type. The CST value is zero extended,
2622 truncated, or unchanged to make it fit in a pointer size. This one is
2623 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2624
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2625 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2626 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2627 are the same as those for the <a href="#i_bitcast">bitcast
2628 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2629
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2630 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2631 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2632 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2633 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2634 instruction, the index list may have zero or more indexes, which are
2635 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2636
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2637 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2638 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2639
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2640 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2641 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2642
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2643 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2644 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2645
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2646 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2647 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2648 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2649
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2650 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2651 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2652 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2653
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2654 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2655 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2656 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2657
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2658 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2659 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2660 constants. The index list is interpreted in a similar manner as indices in
2661 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2662 index value must be specified.</dd>
2663
2664 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2665 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2666 constants. The index list is interpreted in a similar manner as indices in
2667 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2668 index value must be specified.</dd>
2669
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2670 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2671 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2672 be any of the <a href="#binaryops">binary</a>
2673 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2674 on operands are the same as those for the corresponding instruction
2675 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2676</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2677
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2678</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2679
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2680</div>
2681
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2682<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2683<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2684<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2685<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2686<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2687<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2688<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2689</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2690
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2691<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2692
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2693<p>LLVM supports inline assembler expressions (as opposed
2694 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2695 a special value. This value represents the inline assembler as a string
2696 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2697 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2698 expression has side effects, and a flag indicating whether the function
2699 containing the asm needs to align its stack conservatively. An example
2700 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2701
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2702<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2703i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2704</pre>
2705
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2706<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2707 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2708 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2709
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2710<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2711%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2712</pre>
2713
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2714<p>Inline asms with side effects not visible in the constraint list must be
2715 marked as having side effects. This is done through the use of the
2716 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2717
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2718<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2719call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2720</pre>
2721
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2722<p>In some cases inline asms will contain code that will not work unless the
2723 stack is aligned in some way, such as calls or SSE instructions on x86,
2724 yet will not contain code that does that alignment within the asm.
2725 The compiler should make conservative assumptions about what the asm might
2726 contain and should generate its usual stack alignment code in the prologue
2727 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2728
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2729<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2730call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2731</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2732
2733<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2734 first.</p>
2735
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2736<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2737 documented here. Constraints on what can be done (e.g. duplication, moving,
2738 etc need to be documented). This is probably best done by reference to
2739 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2740
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2741<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2742<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2743</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2744
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2745<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2746
2747<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2748 attached to it that contains a list of constant integers. If present, the
2749 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2750 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2751 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2752 source code that produced it. For example:</p>
2753
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2754<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2755call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2756...
2757!42 = !{ i32 1234567 }
2758</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2759
2760<p>It is up to the front-end to make sense of the magic numbers it places in the
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2761 IR. If the MDNode contains multiple constants, the code generator will use
2762 the one that corresponds to the line of the asm that the error occurs on.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2763
2764</div>
2765
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2766</div>
2767
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2768<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2769<h3>
2770 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2771</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2772
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2773<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2774
2775<p>LLVM IR allows metadata to be attached to instructions in the program that
2776 can convey extra information about the code to the optimizers and code
2777 generator. One example application of metadata is source-level debug
2778 information. There are two metadata primitives: strings and nodes. All
2779 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2780 preceding exclamation point ('<tt>!</tt>').</p>
2781
2782<p>A metadata string is a string surrounded by double quotes. It can contain
2783 any character by escaping non-printable characters with "\xx" where "xx" is
2784 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2785
2786<p>Metadata nodes are represented with notation similar to structure constants
2787 (a comma separated list of elements, surrounded by braces and preceded by an
2788 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2789 10}</tt>". Metadata nodes can have any values as their operand.</p>
2790
2791<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2792 metadata nodes, which can be looked up in the module symbol table. For
2793 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2794
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2795<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2796 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2797
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2798<div class="doc_code">
2799<pre>
2800call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2801</pre>
2802</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2803
2804<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2805 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2806
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2807<div class="doc_code">
2808<pre>
2809%indvar.next = add i64 %indvar, 1, !dbg !21
2810</pre>
2811</div>
2812
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2813</div>
2814
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2815</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2816
2817<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2818<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2819 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2820</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2821<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2822<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2823<p>LLVM has a number of "magic" global variables that contain data that affect
2824code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2825of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2826section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2827by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2828
2829<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2830<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2831<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2832</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2833
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2834<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2835
2836<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2837href="#linkage_appending">appending linkage</a>. This array contains a list of
2838pointers to global variables and functions which may optionally have a pointer
2839cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2840
2841<pre>
2842 @X = global i8 4
2843 @Y = global i32 123
2844
2845 @llvm.used = appending global [2 x i8*] [
2846 i8* @X,
2847 i8* bitcast (i32* @Y to i8*)
2848 ], section "llvm.metadata"
2849</pre>
2850
2851<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2852compiler, assembler, and linker are required to treat the symbol as if there is
2853a reference to the global that it cannot see. For example, if a variable has
2854internal linkage and no references other than that from the <tt>@llvm.used</tt>
2855list, it cannot be deleted. This is commonly used to represent references from
2856inline asms and other things the compiler cannot "see", and corresponds to
2857"attribute((used))" in GNU C.</p>
2858
2859<p>On some targets, the code generator must emit a directive to the assembler or
2860object file to prevent the assembler and linker from molesting the symbol.</p>
2861
2862</div>
2863
2864<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2865<h3>
2866 <a name="intg_compiler_used">
2867 The '<tt>llvm.compiler.used</tt>' Global Variable
2868 </a>
2869</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2870
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2871<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2872
2873<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2874<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2875touching the symbol. On targets that support it, this allows an intelligent
2876linker to optimize references to the symbol without being impeded as it would be
2877by <tt>@llvm.used</tt>.</p>
2878
2879<p>This is a rare construct that should only be used in rare circumstances, and
2880should not be exposed to source languages.</p>
2881
2882</div>
2883
2884<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2885<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2886<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2887</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2888
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2889<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2890<pre>
2891%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2892@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2893</pre>
2894<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor functions and associated priorities. The functions referenced by this array will be called in ascending order of priority (i.e. lowest first) when the module is loaded. The order of functions with the same priority is not defined.
2895</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2896
2897</div>
2898
2899<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2900<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2901<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2902</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2903
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2904<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2905<pre>
2906%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2907@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2908</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2909
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2910<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions and associated priorities. The functions referenced by this array will be called in descending order of priority (i.e. highest first) when the module is loaded. The order of functions with the same priority is not defined.
2911</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2912
2913</div>
2914
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2915</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2916
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2917<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2918<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2919<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2920
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2921<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2922
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2923<p>The LLVM instruction set consists of several different classifications of
2924 instructions: <a href="#terminators">terminator
2925 instructions</a>, <a href="#binaryops">binary instructions</a>,
2926 <a href="#bitwiseops">bitwise binary instructions</a>,
2927 <a href="#memoryops">memory instructions</a>, and
2928 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2929
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2930<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2931<h3>
2932 <a name="terminators">Terminator Instructions</a>
2933</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2934
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2935<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2936
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2937<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2938 in a program ends with a "Terminator" instruction, which indicates which
2939 block should be executed after the current block is finished. These
2940 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2941 control flow, not values (the one exception being the
2942 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2943
Duncan Sands83821c82010-04-15 20:35:54 +0000[diff] [blame]2944<p>There are seven different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2945 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2946 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2947 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2948 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2949 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2950 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2951 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2952
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2953<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2954<h4>
2955 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2956</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2957
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2958<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2959
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2960<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2961<pre>
2962 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2963 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2964</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2965
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2966<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2967<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2968 a value) from a function back to the caller.</p>
2969
2970<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2971 value and then causes control flow, and one that just causes control flow to
2972 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2973
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2974<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2975<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2976 return value. The type of the return value must be a
2977 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2978
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2979<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2980 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2981 value or a return value with a type that does not match its type, or if it
2982 has a void return type and contains a '<tt>ret</tt>' instruction with a
2983 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2984
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2985<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2986<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2987 the calling function's context. If the caller is a
2988 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2989 instruction after the call. If the caller was an
2990 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2991 the beginning of the "normal" destination block. If the instruction returns
2992 a value, that value shall set the call or invoke instruction's return
2993 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2994
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2995<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2996<pre>
2997 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2998 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2999 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3000</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3001
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3002</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3003<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3004<h4>
3005 <a name="i_br">'<tt>br</tt>' Instruction</a>
3006</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3007
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3008<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3009
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3010<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3011<pre>
3012 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3013</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3014
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3015<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3016<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3017 different basic block in the current function. There are two forms of this
3018 instruction, corresponding to a conditional branch and an unconditional
3019 branch.</p>
3020
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3021<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3022<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3023 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3024 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3025 target.</p>
3026
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3027<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3028<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3029 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3030 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3031 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3032
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3033<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3034<pre>
3035Test:
3036 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3037 br i1 %cond, label %IfEqual, label %IfUnequal
3038IfEqual:
3039 <a href="#i_ret">ret</a> i32 1
3040IfUnequal:
3041 <a href="#i_ret">ret</a> i32 0
3042</pre>
3043
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3044</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3045
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3046<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3047<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3048 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3049</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3050
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3051<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3052
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3053<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3054<pre>
3055 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3056</pre>
3057
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3058<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3059<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3060 several different places. It is a generalization of the '<tt>br</tt>'
3061 instruction, allowing a branch to occur to one of many possible
3062 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3063
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3064<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3065<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3066 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3067 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3068 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3069
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3070<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3071<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3072 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3073 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3074 transferred to the corresponding destination; otherwise, control flow is
3075 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3076
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3077<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3078<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3079 <tt>switch</tt> instruction, this instruction may be code generated in
3080 different ways. For example, it could be generated as a series of chained
3081 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3082
3083<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3084<pre>
3085 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3086 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3087 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3088
3089 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3090 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3091
3092 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3093 switch i32 %val, label %otherwise [ i32 0, label %onzero
3094 i32 1, label %onone
3095 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3096</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3097
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3098</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3099
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3100
3101<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3102<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3103 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3104</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3105
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3106<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3107
3108<h5>Syntax:</h5>
3109<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3110 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3111</pre>
3112
3113<h5>Overview:</h5>
3114
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3115<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3116 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3117 "<tt>address</tt>". Address must be derived from a <a
3118 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3119
3120<h5>Arguments:</h5>
3121
3122<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3123 rest of the arguments indicate the full set of possible destinations that the
3124 address may point to. Blocks are allowed to occur multiple times in the
3125 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3126
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3127<p>This destination list is required so that dataflow analysis has an accurate
3128 understanding of the CFG.</p>
3129
3130<h5>Semantics:</h5>
3131
3132<p>Control transfers to the block specified in the address argument. All
3133 possible destination blocks must be listed in the label list, otherwise this
3134 instruction has undefined behavior. This implies that jumps to labels
3135 defined in other functions have undefined behavior as well.</p>
3136
3137<h5>Implementation:</h5>
3138
3139<p>This is typically implemented with a jump through a register.</p>
3140
3141<h5>Example:</h5>
3142<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3143 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3144</pre>
3145
3146</div>
3147
3148
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3149<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3150<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3151 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3152</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3153
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3154<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3155
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3156<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3157<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3158 &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 Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]3159 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3160</pre>
3161
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3162<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3163<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3164 function, with the possibility of control flow transfer to either the
3165 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3166 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3167 control flow will return to the "normal" label. If the callee (or any
3168 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3169 instruction, control is interrupted and continued at the dynamically nearest
3170 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3171
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3172<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3173<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3174
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3175<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3176 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3177 convention</a> the call should use. If none is specified, the call
3178 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3179
3180 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3181 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3182 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3183
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3184 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3185 function value being invoked. In most cases, this is a direct function
3186 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3187 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3188
3189 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3190 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3191
3192 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3193 signature argument types and parameter attributes. All arguments must be
3194 of <a href="#t_firstclass">first class</a> type. If the function
3195 signature indicates the function accepts a variable number of arguments,
3196 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3197
3198 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3199 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3200
3201 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3202 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3203
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3204 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3205 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3206 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3207</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3208
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3209<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3210<p>This instruction is designed to operate as a standard
3211 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3212 primary difference is that it establishes an association with a label, which
3213 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3214
3215<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3216 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3217 exception. Additionally, this is important for implementation of
3218 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3219
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3220<p>For the purposes of the SSA form, the definition of the value returned by the
3221 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3222 block to the "normal" label. If the callee unwinds then no return value is
3223 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3224
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3225<p>Note that the code generator does not yet completely support unwind, and
3226that the invoke/unwind semantics are likely to change in future versions.</p>
3227
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3228<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3229<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3230 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3231 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3232 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3233 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3234</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3235
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3236</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3237
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3238<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3239
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3240<h4>
3241 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3242</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3243
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3244<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3245
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3246<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3247<pre>
3248 unwind
3249</pre>
3250
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3251<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3252<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3253 at the first callee in the dynamic call stack which used
3254 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3255 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3256
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3257<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3258<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3259 immediately halt. The dynamic call stack is then searched for the
3260 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3261 Once found, execution continues at the "exceptional" destination block
3262 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3263 instruction in the dynamic call chain, undefined behavior results.</p>
3264
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3265<p>Note that the code generator does not yet completely support unwind, and
3266that the invoke/unwind semantics are likely to change in future versions.</p>
3267
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3268</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3269
3270<!-- _______________________________________________________________________ -->
3271
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3272<h4>
3273 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3274</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3275
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3276<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3277
3278<h5>Syntax:</h5>
3279<pre>
3280 unreachable
3281</pre>
3282
3283<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3284<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3285 instruction is used to inform the optimizer that a particular portion of the
3286 code is not reachable. This can be used to indicate that the code after a
3287 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3288
3289<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3290<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3291
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3292</div>
3293
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3294</div>
3295
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3296<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3297<h3>
3298 <a name="binaryops">Binary Operations</a>
3299</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3300
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3301<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3302
3303<p>Binary operators are used to do most of the computation in a program. They
3304 require two operands of the same type, execute an operation on them, and
3305 produce a single value. The operands might represent multiple data, as is
3306 the case with the <a href="#t_vector">vector</a> data type. The result value
3307 has the same type as its operands.</p>
3308
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3309<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3310
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3311<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3312<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3313 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3314</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3315
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3316<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3317
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3318<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3319<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3320 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3321 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3322 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3323 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3324</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3326<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3327<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3328
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3329<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3330<p>The two arguments to the '<tt>add</tt>' instruction must
3331 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3332 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3333
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3334<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3335<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3336
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3337<p>If the sum has unsigned overflow, the result returned is the mathematical
3338 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3339
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3340<p>Because LLVM integers use a two's complement representation, this instruction
3341 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3342
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3343<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3344 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3345 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3346 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3347 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3348
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3349<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3350<pre>
3351 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3352</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3353
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3354</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3355
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3356<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3357<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3358 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3359</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3360
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3361<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3362
3363<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3364<pre>
3365 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3366</pre>
3367
3368<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3369<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3370
3371<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3372<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3373 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3374 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3375
3376<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3377<p>The value produced is the floating point sum of the two operands.</p>
3378
3379<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3380<pre>
3381 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3382</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3383
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3384</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3385
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3386<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3387<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3388 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3389</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3390
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3391<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3392
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3393<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3394<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3395 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3396 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3397 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3398 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3399</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3400
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3401<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3402<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3403 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3404
3405<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3406 '<tt>neg</tt>' instruction present in most other intermediate
3407 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3408
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3409<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3410<p>The two arguments to the '<tt>sub</tt>' instruction must
3411 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3412 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3413
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3414<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3415<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3416
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3417<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3418 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3419 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3420
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3421<p>Because LLVM integers use a two's complement representation, this instruction
3422 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3423
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3424<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3425 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3426 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3427 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3428 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3429
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3430<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3431<pre>
3432 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3433 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3434</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3435
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3436</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3437
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3438<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3439<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3440 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3441</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3442
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3443<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3444
3445<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3446<pre>
3447 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3448</pre>
3449
3450<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3451<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3452 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3453
3454<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3455 '<tt>fneg</tt>' instruction present in most other intermediate
3456 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3457
3458<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3459<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3460 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3461 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3462
3463<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3464<p>The value produced is the floating point difference of the two operands.</p>
3465
3466<h5>Example:</h5>
3467<pre>
3468 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3469 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3470</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3471
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3472</div>
3473
3474<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3475<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3476 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3477</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3478
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3479<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3480
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3481<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3482<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3483 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3484 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3485 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3486 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3487</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3488
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3489<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3490<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3491
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3492<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3493<p>The two arguments to the '<tt>mul</tt>' instruction must
3494 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3495 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3496
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3497<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3498<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3499
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3500<p>If the result of the multiplication has unsigned overflow, the result
3501 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3502 width of the result.</p>
3503
3504<p>Because LLVM integers use a two's complement representation, and the result
3505 is the same width as the operands, this instruction returns the correct
3506 result for both signed and unsigned integers. If a full product
3507 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3508 be sign-extended or zero-extended as appropriate to the width of the full
3509 product.</p>
3510
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3511<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3512 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3513 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3514 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3515 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3516
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3517<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3518<pre>
3519 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3520</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3521
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3522</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3523
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3524<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3525<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3526 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3527</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3528
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3529<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3530
3531<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3532<pre>
3533 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3534</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3535
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3536<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3537<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3538
3539<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3540<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3541 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3542 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3543
3544<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3545<p>The value produced is the floating point product of the two operands.</p>
3546
3547<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3548<pre>
3549 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3550</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3551
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3552</div>
3553
3554<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3555<h4>
3556 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3557</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3558
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3559<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3560
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3561<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3562<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3563 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3564 &lt;result&gt; = udiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3565</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3566
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3567<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3568<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3569
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3570<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3571<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3572 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3573 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3574
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3575<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3576<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3577
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3578<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3579 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3580
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3581<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3582
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3583<p>If the <tt>exact</tt> keyword is present, the result value of the
3584 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3585 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3586
3587
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3588<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3589<pre>
3590 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3591</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3592
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3593</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3594
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3595<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3596<h4>
3597 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3598</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3599
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3600<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3601
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3602<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3603<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3604 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3605 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3606</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3607
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3608<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3609<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3610
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3611<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3612<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3613 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3614 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3615
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3616<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3617<p>The value produced is the signed integer quotient of the two operands rounded
3618 towards zero.</p>
3619
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3620<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3621 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3622
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3623<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3624 undefined behavior; this is a rare case, but can occur, for example, by doing
3625 a 32-bit division of -2147483648 by -1.</p>
3626
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3627<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3628 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
Dan Gohman38da9272010-07-11 00:08:34 +0000[diff] [blame]3629 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3630
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3631<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3632<pre>
3633 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3634</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3635
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3636</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3637
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3638<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3639<h4>
3640 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3641</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3642
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3643<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3644
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3645<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3646<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3647 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3648</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3649
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3650<h5>Overview:</h5>
3651<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3652
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3653<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3654<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3655 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3656 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3657
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3658<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3659<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3660
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3661<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3662<pre>
3663 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3664</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3665
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3666</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3667
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3668<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3669<h4>
3670 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3671</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3672
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3673<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3674
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3675<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3676<pre>
3677 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3678</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3679
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3680<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3681<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3682 division of its two arguments.</p>
3683
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3684<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3685<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3686 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3687 values. Both arguments must have identical types.</p>
3688
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3689<h5>Semantics:</h5>
3690<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3691 This instruction always performs an unsigned division to get the
3692 remainder.</p>
3693
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3694<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3695 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3696
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3697<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3698
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3699<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3700<pre>
3701 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3702</pre>
3703
3704</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3705
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3706<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3707<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3708 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3709</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3710
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3711<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3712
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3713<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3714<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3715 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3716</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3717
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3718<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3719<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3720 division of its two operands. This instruction can also take
3721 <a href="#t_vector">vector</a> versions of the values in which case the
3722 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3723
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3724<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3725<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3726 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3727 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3728
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3729<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3730<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3731 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3732 <i>modulo</i> operator (where the result is either zero or has the same sign
3733 as the divisor, <tt>op2</tt>) of a value.
3734 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3735 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3736 Math Forum</a>. For a table of how this is implemented in various languages,
3737 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3738 Wikipedia: modulo operation</a>.</p>
3739
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3740<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3741 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3742
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3743<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3744 Overflow also leads to undefined behavior; this is a rare case, but can
3745 occur, for example, by taking the remainder of a 32-bit division of
3746 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3747 lets srem be implemented using instructions that return both the result of
3748 the division and the remainder.)</p>
3749
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3750<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3751<pre>
3752 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3753</pre>
3754
3755</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3756
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3757<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3758<h4>
3759 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3760</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3761
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3762<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3763
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3764<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3765<pre>
3766 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3767</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3768
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3769<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3770<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3771 its two operands.</p>
3772
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3773<h5>Arguments:</h5>
3774<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3775 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3776 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3777
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3778<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3779<p>This instruction returns the <i>remainder</i> of a division. The remainder
3780 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3781
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3782<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3783<pre>
3784 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3785</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3786
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3787</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3788
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3789</div>
3790
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3791<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3792<h3>
3793 <a name="bitwiseops">Bitwise Binary Operations</a>
3794</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3795
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3796<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3797
3798<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3799 program. They are generally very efficient instructions and can commonly be
3800 strength reduced from other instructions. They require two operands of the
3801 same type, execute an operation on them, and produce a single value. The
3802 resulting value is the same type as its operands.</p>
3803
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3804<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3805<h4>
3806 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3807</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3808
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3809<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3810
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3811<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3812<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3813 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3814 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3815 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3816 &lt;result&gt; = shl nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3817</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3818
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3819<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3820<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3821 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3822
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3823<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3824<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3825 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3826 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3827
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3828<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3829<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3830 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3831 is (statically or dynamically) negative or equal to or larger than the number
3832 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3833 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3834 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3835
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3836<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3837 <a href="#trapvalues">trap value</a> if it shifts out any non-zero bits. If
Chris Lattner66298c12011-02-09 16:44:44 +0000[diff] [blame]3838 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3839 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3840 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3841 they would if the shift were expressed as a mul instruction with the same
3842 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3843
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3844<h5>Example:</h5>
3845<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3846 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3847 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3848 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3849 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3850 &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 Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3851</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3852
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3853</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3854
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3855<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3856<h4>
3857 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3858</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3859
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3860<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3861
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3862<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3863<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3864 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3865 &lt;result&gt; = lshr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3866</pre>
3867
3868<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3869<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3870 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3871
3872<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3873<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3874 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3875 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3876
3877<h5>Semantics:</h5>
3878<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3879 significant bits of the result will be filled with zero bits after the shift.
3880 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3881 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3882 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3883 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3884
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3885<p>If the <tt>exact</tt> keyword is present, the result value of the
3886 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3887 shifted out are non-zero.</p>
3888
3889
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3890<h5>Example:</h5>
3891<pre>
3892 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3893 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3894 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3895 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3896 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3897 &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 Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3898</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3899
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3900</div>
3901
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3902<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3903<h4>
3904 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3905</h4>
3906
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3907<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3908
3909<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3910<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3911 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3912 &lt;result&gt; = ashr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3913</pre>
3914
3915<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3916<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3917 operand shifted to the right a specified number of bits with sign
3918 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3919
3920<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3921<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3922 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3923 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3924
3925<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3926<p>This instruction always performs an arithmetic shift right operation, The
3927 most significant bits of the result will be filled with the sign bit
3928 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3929 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3930 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3931 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3932
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3933<p>If the <tt>exact</tt> keyword is present, the result value of the
3934 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3935 shifted out are non-zero.</p>
3936
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3937<h5>Example:</h5>
3938<pre>
3939 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3940 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3941 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3942 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3943 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3944 &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 Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3945</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3946
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3947</div>
3948
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3949<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3950<h4>
3951 <a name="i_and">'<tt>and</tt>' Instruction</a>
3952</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3953
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3954<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3955
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3956<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3957<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3958 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3959</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3960
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3961<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3962<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3963 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3964
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3965<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3966<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3967 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3968 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3969
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3970<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3971<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3972
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3973<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3974 <tbody>
3975 <tr>
3976 <td>In0</td>
3977 <td>In1</td>
3978 <td>Out</td>
3979 </tr>
3980 <tr>
3981 <td>0</td>
3982 <td>0</td>
3983 <td>0</td>
3984 </tr>
3985 <tr>
3986 <td>0</td>
3987 <td>1</td>
3988 <td>0</td>
3989 </tr>
3990 <tr>
3991 <td>1</td>
3992 <td>0</td>
3993 <td>0</td>
3994 </tr>
3995 <tr>
3996 <td>1</td>
3997 <td>1</td>
3998 <td>1</td>
3999 </tr>
4000 </tbody>
4001</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4002
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4003<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4004<pre>
4005 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4006 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4007 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4008</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4009</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4010<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4011<h4>
4012 <a name="i_or">'<tt>or</tt>' Instruction</a>
4013</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4014
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4015<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4016
4017<h5>Syntax:</h5>
4018<pre>
4019 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4020</pre>
4021
4022<h5>Overview:</h5>
4023<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4024 two operands.</p>
4025
4026<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4027<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4028 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4029 values. Both arguments must have identical types.</p>
4030
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4031<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4032<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4033
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4034<table border="1" cellspacing="0" cellpadding="4">
4035 <tbody>
4036 <tr>
4037 <td>In0</td>
4038 <td>In1</td>
4039 <td>Out</td>
4040 </tr>
4041 <tr>
4042 <td>0</td>
4043 <td>0</td>
4044 <td>0</td>
4045 </tr>
4046 <tr>
4047 <td>0</td>
4048 <td>1</td>
4049 <td>1</td>
4050 </tr>
4051 <tr>
4052 <td>1</td>
4053 <td>0</td>
4054 <td>1</td>
4055 </tr>
4056 <tr>
4057 <td>1</td>
4058 <td>1</td>
4059 <td>1</td>
4060 </tr>
4061 </tbody>
4062</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4063
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4064<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4065<pre>
4066 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4067 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4068 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4069</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4070
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4071</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4072
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4073<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4074<h4>
4075 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4076</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4077
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4078<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4079
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4080<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4081<pre>
4082 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4083</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4084
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4085<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4086<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4087 its two operands. The <tt>xor</tt> is used to implement the "one's
4088 complement" operation, which is the "~" operator in C.</p>
4089
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4090<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4091<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4092 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4093 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4094
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4095<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4096<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4097
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4098<table border="1" cellspacing="0" cellpadding="4">
4099 <tbody>
4100 <tr>
4101 <td>In0</td>
4102 <td>In1</td>
4103 <td>Out</td>
4104 </tr>
4105 <tr>
4106 <td>0</td>
4107 <td>0</td>
4108 <td>0</td>
4109 </tr>
4110 <tr>
4111 <td>0</td>
4112 <td>1</td>
4113 <td>1</td>
4114 </tr>
4115 <tr>
4116 <td>1</td>
4117 <td>0</td>
4118 <td>1</td>
4119 </tr>
4120 <tr>
4121 <td>1</td>
4122 <td>1</td>
4123 <td>0</td>
4124 </tr>
4125 </tbody>
4126</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4127
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4128<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4129<pre>
4130 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4131 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4132 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4133 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4134</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4135
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4136</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4137
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4138</div>
4139
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4140<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4141<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4142 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4143</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4144
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4145<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4146
4147<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4148 target-independent manner. These instructions cover the element-access and
4149 vector-specific operations needed to process vectors effectively. While LLVM
4150 does directly support these vector operations, many sophisticated algorithms
4151 will want to use target-specific intrinsics to take full advantage of a
4152 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4153
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4154<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4155<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4156 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4157</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4158
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4159<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4160
4161<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4162<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4163 &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 Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4164</pre>
4165
4166<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4167<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4168 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4169
4170
4171<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4172<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4173 of <a href="#t_vector">vector</a> type. The second operand is an index
4174 indicating the position from which to extract the element. The index may be
4175 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4176
4177<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4178<p>The result is a scalar of the same type as the element type of
4179 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4180 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4181 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4182
4183<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4184<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4185 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4186</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4187
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4188</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4189
4190<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4191<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4192 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4193</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4194
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4195<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4196
4197<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4198<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4199 &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 Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4200</pre>
4201
4202<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4203<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4204 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4205
4206<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4207<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4208 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4209 whose type must equal the element type of the first operand. The third
4210 operand is an index indicating the position at which to insert the value.
4211 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4212
4213<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4214<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4215 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4216 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4217 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4218
4219<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4220<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4221 &lt;result&gt; = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4222</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4223
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4224</div>
4225
4226<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4227<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4228 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4229</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4230
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4231<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4232
4233<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4234<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4235 &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 Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4236</pre>
4237
4238<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4239<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4240 from two input vectors, returning a vector with the same element type as the
4241 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4242
4243<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4244<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4245 with types that match each other. The third argument is a shuffle mask whose
4246 element type is always 'i32'. The result of the instruction is a vector
4247 whose length is the same as the shuffle mask and whose element type is the
4248 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4249
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4250<p>The shuffle mask operand is required to be a constant vector with either
4251 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4252
4253<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4254<p>The elements of the two input vectors are numbered from left to right across
4255 both of the vectors. The shuffle mask operand specifies, for each element of
4256 the result vector, which element of the two input vectors the result element
4257 gets. The element selector may be undef (meaning "don't care") and the
4258 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4259
4260<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4261<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4262 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4263 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4264 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4265 &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 Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4266 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4267 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4268 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4269 &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 Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4270</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4271
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4272</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4273
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4274</div>
4275
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4276<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4277<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4278 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4279</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4280
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4281<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4282
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4283<p>LLVM supports several instructions for working with
4284 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4285
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4286<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4287<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4288 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4289</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4290
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4291<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4292
4293<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4294<pre>
4295 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4296</pre>
4297
4298<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4299<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4300 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4301
4302<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4303<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4304 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4305 <a href="#t_array">array</a> type. The operands are constant indices to
4306 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4307 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4308 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4309 <ul>
4310 <li>Since the value being indexed is not a pointer, the first index is
4311 omitted and assumed to be zero.</li>
4312 <li>At least one index must be specified.</li>
4313 <li>Not only struct indices but also array indices must be in
4314 bounds.</li>
4315 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4316
4317<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4318<p>The result is the value at the position in the aggregate specified by the
4319 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4320
4321<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4322<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4323 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4324</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4325
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4326</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4327
4328<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4329<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4330 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4331</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4332
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4333<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4334
4335<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4336<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4337 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4338</pre>
4339
4340<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4341<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4342 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4343
4344<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4345<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4346 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4347 <a href="#t_array">array</a> type. The second operand is a first-class
4348 value to insert. The following operands are constant indices indicating
4349 the position at which to insert the value in a similar manner as indices in a
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4350 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4351 value to insert must have the same type as the value identified by the
4352 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4353
4354<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4355<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4356 that of <tt>val</tt> except that the value at the position specified by the
4357 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4358
4359<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4360<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4361 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4362 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4363 %agg3 = insertvalue {i32, {float}} %agg1, float %val, 1, 0 <i>; yields {i32 1, float %val}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4364</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4365
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4366</div>
4367
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4368</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4369
4370<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4371<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4372 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4373</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4374
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4375<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4376
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4377<p>A key design point of an SSA-based representation is how it represents
4378 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4379 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4380 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4381
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4382<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4383<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4384 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4385</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4386
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4387<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4388
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4389<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4390<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4391 &lt;result&gt; = alloca &lt;type&gt;[, &lt;ty&gt; &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4392</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4394<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4395<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4396 currently executing function, to be automatically released when this function
4397 returns to its caller. The object is always allocated in the generic address
4398 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4400<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4401<p>The '<tt>alloca</tt>' instruction
4402 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4403 runtime stack, returning a pointer of the appropriate type to the program.
4404 If "NumElements" is specified, it is the number of elements allocated,
4405 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4406 specified, the value result of the allocation is guaranteed to be aligned to
4407 at least that boundary. If not specified, or if zero, the target can choose
4408 to align the allocation on any convenient boundary compatible with the
4409 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4410
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4411<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4412
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4413<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4414<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4415 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4416 memory is automatically released when the function returns. The
4417 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4418 variables that must have an address available. When the function returns
4419 (either with the <tt><a href="#i_ret">ret</a></tt>
4420 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4421 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4422
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4423<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4424<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4425 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4426 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4427 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4428 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4429</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4430
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4431</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4433<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4434<h4>
4435 <a name="i_load">'<tt>load</tt>' Instruction</a>
4436</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4437
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4438<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4439
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4440<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4441<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4442 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4443 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4444 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4445</pre>
4446
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4447<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4448<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4449
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4450<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4451<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4452 from which to load. The pointer must point to
4453 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4454 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4455 number or order of execution of this <tt>load</tt> with other <a
4456 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4457
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4458<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4459 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4460 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4461 alignment for the target. It is the responsibility of the code emitter to
4462 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4463 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4464 produce less efficient code. An alignment of 1 is always safe.</p>
4465
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4466<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4467 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4468 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4469 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4470 and code generator that this load is not expected to be reused in the cache.
4471 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4472 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4473
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4474<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4475<p>The location of memory pointed to is loaded. If the value being loaded is of
4476 scalar type then the number of bytes read does not exceed the minimum number
4477 of bytes needed to hold all bits of the type. For example, loading an
4478 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4479 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4480 is undefined if the value was not originally written using a store of the
4481 same type.</p>
4482
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4483<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4484<pre>
4485 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4486 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4487 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4488</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4489
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4490</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4491
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4492<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4493<h4>
4494 <a name="i_store">'<tt>store</tt>' Instruction</a>
4495</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4496
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4497<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4498
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4499<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4500<pre>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4501 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4502 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4503</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4504
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4505<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4506<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4507
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4508<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4509<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4510 and an address at which to store it. The type of the
4511 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4512 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4513 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4514 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4515 order of execution of this <tt>store</tt> with other <a
4516 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4517
4518<p>The optional constant "align" argument specifies the alignment of the
4519 operation (that is, the alignment of the memory address). A value of 0 or an
4520 omitted "align" argument means that the operation has the preferential
4521 alignment for the target. It is the responsibility of the code emitter to
4522 ensure that the alignment information is correct. Overestimating the
4523 alignment results in an undefined behavior. Underestimating the alignment may
4524 produce less efficient code. An alignment of 1 is always safe.</p>
4525
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4526<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4527 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4528 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4529 instruction tells the optimizer and code generator that this load is
4530 not expected to be reused in the cache. The code generator may
4531 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4532 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4533
4534
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4535<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4536<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4537 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4538 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4539 does not exceed the minimum number of bytes needed to hold all bits of the
4540 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4541 writing a value of a type like <tt>i20</tt> with a size that is not an
4542 integral number of bytes, it is unspecified what happens to the extra bits
4543 that do not belong to the type, but they will typically be overwritten.</p>
4544
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4545<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4546<pre>
4547 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4548 store i32 3, i32* %ptr <i>; yields {void}</i>
4549 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4550</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4551
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4552</div>
4553
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4554<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4555<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4556 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4557</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4558
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4559<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4560
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4561<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4562<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4563 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4564 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4565</pre>
4566
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4567<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4568<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4569 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4570 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4571
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4572<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4573<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4574 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4575 elements of the aggregate object are indexed. The interpretation of each
4576 index is dependent on the type being indexed into. The first index always
4577 indexes the pointer value given as the first argument, the second index
4578 indexes a value of the type pointed to (not necessarily the value directly
4579 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4580 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4581 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4582 can never be pointers, since that would require loading the pointer before
4583 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4584
4585<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4586 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4587 integer <b>constants</b> are allowed. When indexing into an array, pointer
4588 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4589 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4590
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4591<p>For example, let's consider a C code fragment and how it gets compiled to
4592 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4593
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4594<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4595struct RT {
4596 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4597 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4598 char C;
4599};
4600struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4601 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4602 double Y;
4603 struct RT Z;
4604};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4605
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4606int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4607 return &amp;s[1].Z.B[5][13];
4608}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4609</pre>
4610
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4611<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4612
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4613<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4614%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4615%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4616
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4617define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4618entry:
4619 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4620 ret i32* %reg
4621}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4622</pre>
4623
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4624<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4625<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4626 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4627 }</tt>' type, a structure. The second index indexes into the third element
4628 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4629 i8 }</tt>' type, another structure. The third index indexes into the second
4630 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4631 array. The two dimensions of the array are subscripted into, yielding an
4632 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4633 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4634
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4635<p>Note that it is perfectly legal to index partially through a structure,
4636 returning a pointer to an inner element. Because of this, the LLVM code for
4637 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4638
4639<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4640 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4641 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4642 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4643 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4644 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4645 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4646 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4647 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4648</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4649
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4650<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4651 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4652 base pointer is not an <i>in bounds</i> address of an allocated object,
4653 or if any of the addresses that would be formed by successive addition of
4654 the offsets implied by the indices to the base address with infinitely
4655 precise arithmetic are not an <i>in bounds</i> address of that allocated
4656 object. The <i>in bounds</i> addresses for an allocated object are all
4657 the addresses that point into the object, plus the address one byte past
4658 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4659
4660<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4661 the base address with silently-wrapping two's complement arithmetic, and
4662 the result value of the <tt>getelementptr</tt> may be outside the object
4663 pointed to by the base pointer. The result value may not necessarily be
4664 used to access memory though, even if it happens to point into allocated
4665 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4666 section for more information.</p>
4667
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4668<p>The getelementptr instruction is often confusing. For some more insight into
4669 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4670
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4671<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4672<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4673 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4674 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4675 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4676 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4677 <i>; yields i8*:eptr</i>
4678 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4679 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4680 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4681</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4682
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4683</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4684
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4685</div>
4686
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4687<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4688<h3>
4689 <a name="convertops">Conversion Operations</a>
4690</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4691
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4692<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4693
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4694<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4695 which all take a single operand and a type. They perform various bit
4696 conversions on the operand.</p>
4697
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4698<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4699<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4700 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4701</h4>
4702
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4703<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4704
4705<h5>Syntax:</h5>
4706<pre>
4707 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4708</pre>
4709
4710<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4711<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4712 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4713
4714<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4715<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4716 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4717 of the same number of integers.
4718 The bit size of the <tt>value</tt> must be larger than
4719 the bit size of the destination type, <tt>ty2</tt>.
4720 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4721
4722<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4723<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4724 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4725 source size must be larger than the destination size, <tt>trunc</tt> cannot
4726 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4727
4728<h5>Example:</h5>
4729<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4730 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4731 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4732 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4733 %W = trunc &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i8&gt; <i>; yields &lt;i8 8, i8 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4734</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4735
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4736</div>
4737
4738<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4739<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4740 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4741</h4>
4742
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4743<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4744
4745<h5>Syntax:</h5>
4746<pre>
4747 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4748</pre>
4749
4750<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4751<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4752 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4753
4754
4755<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4756<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4757 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4758 of the same number of integers.
4759 The bit size of the <tt>value</tt> must be smaller than
4760 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4761 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4762
4763<h5>Semantics:</h5>
4764<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4765 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4766
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4767<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4768
4769<h5>Example:</h5>
4770<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4771 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4772 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4773 %Z = zext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4774</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4775
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4776</div>
4777
4778<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4779<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4780 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4781</h4>
4782
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4783<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4784
4785<h5>Syntax:</h5>
4786<pre>
4787 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4788</pre>
4789
4790<h5>Overview:</h5>
4791<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4792
4793<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4794<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4795 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4796 of the same number of integers.
4797 The bit size of the <tt>value</tt> must be smaller than
4798 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4799 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4800
4801<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4802<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4803 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4804 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4805
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4806<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4807
4808<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4809<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4810 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4811 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4812 %Z = sext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4813</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4814
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4815</div>
4816
4817<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4818<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4819 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4820</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4821
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4822<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4823
4824<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4825<pre>
4826 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4827</pre>
4828
4829<h5>Overview:</h5>
4830<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4831 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4832
4833<h5>Arguments:</h5>
4834<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4835 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4836 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4837 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4838 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4839
4840<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4841<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4842 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4843 <a href="#t_floating">floating point</a> type. If the value cannot fit
4844 within the destination type, <tt>ty2</tt>, then the results are
4845 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4846
4847<h5>Example:</h5>
4848<pre>
4849 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4850 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4851</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4852
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4853</div>
4854
4855<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4856<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4857 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4858</h4>
4859
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4860<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4861
4862<h5>Syntax:</h5>
4863<pre>
4864 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4865</pre>
4866
4867<h5>Overview:</h5>
4868<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4869 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4870
4871<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4872<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4873 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4874 a <a href="#t_floating">floating point</a> type to cast it to. The source
4875 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4876
4877<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4878<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4879 <a href="#t_floating">floating point</a> type to a larger
4880 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4881 used to make a <i>no-op cast</i> because it always changes bits. Use
4882 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4883
4884<h5>Example:</h5>
4885<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]4886 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4887 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4888</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4889
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4890</div>
4891
4892<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4893<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4894 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4895</h4>
4896
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4897<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4898
4899<h5>Syntax:</h5>
4900<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4901 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4902</pre>
4903
4904<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4905<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4906 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4907
4908<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4909<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4910 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4911 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4912 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4913 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4914
4915<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4916<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4917 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4918 towards zero) unsigned integer value. If the value cannot fit
4919 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4920
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4921<h5>Example:</h5>
4922<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4923 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4924 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4925 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4926</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4927
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4928</div>
4929
4930<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4931<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4932 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4933</h4>
4934
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4935<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4936
4937<h5>Syntax:</h5>
4938<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4939 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4940</pre>
4941
4942<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4943<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4944 <a href="#t_floating">floating point</a> <tt>value</tt> to
4945 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4946
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4947<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4948<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4949 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4950 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4951 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4952 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4953
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4954<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4955<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4956 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4957 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4958 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4959
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4960<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4961<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4962 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4963 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4964 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4965</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4966
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4967</div>
4968
4969<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4970<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4971 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4972</h4>
4973
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4974<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4975
4976<h5>Syntax:</h5>
4977<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4978 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4979</pre>
4980
4981<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4982<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4983 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4984
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4985<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4986<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4987 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4988 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4989 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4990 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4991
4992<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4993<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4994 integer quantity and converts it to the corresponding floating point
4995 value. If the value cannot fit in the floating point value, the results are
4996 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4997
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4998<h5>Example:</h5>
4999<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5000 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5001 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5002</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5003
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5004</div>
5005
5006<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5007<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5008 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5009</h4>
5010
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5011<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5012
5013<h5>Syntax:</h5>
5014<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5015 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5016</pre>
5017
5018<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5019<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5020 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5021
5022<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5023<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5024 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5025 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5026 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5027 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5028
5029<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5030<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5031 quantity and converts it to the corresponding floating point value. If the
5032 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5033
5034<h5>Example:</h5>
5035<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5036 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5037 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5038</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5039
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5040</div>
5041
5042<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5043<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5044 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5045</h4>
5046
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5047<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5048
5049<h5>Syntax:</h5>
5050<pre>
5051 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5052</pre>
5053
5054<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5055<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5056 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5057
5058<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5059<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5060 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5061 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5062
5063<h5>Semantics:</h5>
5064<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5065 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5066 truncating or zero extending that value to the size of the integer type. If
5067 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5068 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5069 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5070 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5071
5072<h5>Example:</h5>
5073<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5074 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5075 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5076</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5077
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5078</div>
5079
5080<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5081<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5082 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5083</h4>
5084
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5085<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5086
5087<h5>Syntax:</h5>
5088<pre>
5089 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5090</pre>
5091
5092<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5093<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5094 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5095
5096<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5097<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5098 value to cast, and a type to cast it to, which must be a
5099 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5100
5101<h5>Semantics:</h5>
5102<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5103 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5104 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5105 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5106 than the size of a pointer then a zero extension is done. If they are the
5107 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5108
5109<h5>Example:</h5>
5110<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5111 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5112 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5113 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5114</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5115
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5116</div>
5117
5118<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5119<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5120 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5121</h4>
5122
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5123<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5124
5125<h5>Syntax:</h5>
5126<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5127 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5128</pre>
5129
5130<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5131<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5132 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5133
5134<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5135<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5136 non-aggregate first class value, and a type to cast it to, which must also be
5137 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5138 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5139 identical. If the source type is a pointer, the destination type must also be
5140 a pointer. This instruction supports bitwise conversion of vectors to
5141 integers and to vectors of other types (as long as they have the same
5142 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5143
5144<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5145<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5146 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5147 this conversion. The conversion is done as if the <tt>value</tt> had been
5148 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5149 be converted to other pointer types with this instruction. To convert
5150 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5151 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5152
5153<h5>Example:</h5>
5154<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5155 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5156 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5157 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5158</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5159
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5160</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5161
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5162</div>
5163
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5164<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5165<h3>
5166 <a name="otherops">Other Operations</a>
5167</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5168
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5169<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5170
5171<p>The instructions in this category are the "miscellaneous" instructions, which
5172 defy better classification.</p>
5173
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5174<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5175<h4>
5176 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5177</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5178
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5179<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5180
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5181<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5182<pre>
5183 &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 Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5184</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5185
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5186<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5187<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5188 boolean values based on comparison of its two integer, integer vector, or
5189 pointer operands.</p>
5190
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5191<h5>Arguments:</h5>
5192<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5193 the condition code indicating the kind of comparison to perform. It is not a
5194 value, just a keyword. The possible condition code are:</p>
5195
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5196<ol>
5197 <li><tt>eq</tt>: equal</li>
5198 <li><tt>ne</tt>: not equal </li>
5199 <li><tt>ugt</tt>: unsigned greater than</li>
5200 <li><tt>uge</tt>: unsigned greater or equal</li>
5201 <li><tt>ult</tt>: unsigned less than</li>
5202 <li><tt>ule</tt>: unsigned less or equal</li>
5203 <li><tt>sgt</tt>: signed greater than</li>
5204 <li><tt>sge</tt>: signed greater or equal</li>
5205 <li><tt>slt</tt>: signed less than</li>
5206 <li><tt>sle</tt>: signed less or equal</li>
5207</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5208
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5209<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5210 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5211 typed. They must also be identical types.</p>
5212
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5213<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5214<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5215 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5216 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5217 result, as follows:</p>
5218
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5219<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5220 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5221 <tt>false</tt> otherwise. No sign interpretation is necessary or
5222 performed.</li>
5223
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5224 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5225 <tt>false</tt> otherwise. No sign interpretation is necessary or
5226 performed.</li>
5227
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5228 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5229 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5230
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5231 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5232 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5233 to <tt>op2</tt>.</li>
5234
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5235 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5236 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5237
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5238 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5239 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5240
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5241 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5242 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5243
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5244 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5245 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5246 to <tt>op2</tt>.</li>
5247
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5248 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5249 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5250
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5251 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5252 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5253</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5254
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5255<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5256 values are compared as if they were integers.</p>
5257
5258<p>If the operands are integer vectors, then they are compared element by
5259 element. The result is an <tt>i1</tt> vector with the same number of elements
5260 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5261
5262<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5263<pre>
5264 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5265 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5266 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5267 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5268 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5269 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5270</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5271
5272<p>Note that the code generator does not yet support vector types with
5273 the <tt>icmp</tt> instruction.</p>
5274
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5275</div>
5276
5277<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5278<h4>
5279 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5280</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5281
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5282<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5283
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5284<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5285<pre>
5286 &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 Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5287</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5288
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5289<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5290<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5291 values based on comparison of its operands.</p>
5292
5293<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5294(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5295
5296<p>If the operands are floating point vectors, then the result type is a vector
5297 of boolean with the same number of elements as the operands being
5298 compared.</p>
5299
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5300<h5>Arguments:</h5>
5301<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5302 the condition code indicating the kind of comparison to perform. It is not a
5303 value, just a keyword. The possible condition code are:</p>
5304
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5305<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5306 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5307 <li><tt>oeq</tt>: ordered and equal</li>
5308 <li><tt>ogt</tt>: ordered and greater than </li>
5309 <li><tt>oge</tt>: ordered and greater than or equal</li>
5310 <li><tt>olt</tt>: ordered and less than </li>
5311 <li><tt>ole</tt>: ordered and less than or equal</li>
5312 <li><tt>one</tt>: ordered and not equal</li>
5313 <li><tt>ord</tt>: ordered (no nans)</li>
5314 <li><tt>ueq</tt>: unordered or equal</li>
5315 <li><tt>ugt</tt>: unordered or greater than </li>
5316 <li><tt>uge</tt>: unordered or greater than or equal</li>
5317 <li><tt>ult</tt>: unordered or less than </li>
5318 <li><tt>ule</tt>: unordered or less than or equal</li>
5319 <li><tt>une</tt>: unordered or not equal</li>
5320 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5321 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5322</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5323
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5324<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5325 <i>unordered</i> means that either operand may be a QNAN.</p>
5326
5327<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5328 a <a href="#t_floating">floating point</a> type or
5329 a <a href="#t_vector">vector</a> of floating point type. They must have
5330 identical types.</p>
5331
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5332<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5333<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5334 according to the condition code given as <tt>cond</tt>. If the operands are
5335 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5336 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5337 follows:</p>
5338
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5339<ol>
5340 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5341
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5342 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5343 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5344
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5345 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5346 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5347
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5348 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5349 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5350
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5351 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5352 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5353
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5354 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5355 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5356
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5357 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5358 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5359
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5360 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5361
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5362 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5363 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5364
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5365 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5366 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5367
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5368 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5369 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5370
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5371 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5372 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5373
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5374 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5375 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5376
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5377 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5378 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5379
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5380 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5381
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5382 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5383</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5384
5385<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5386<pre>
5387 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5388 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5389 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5390 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5391</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5392
5393<p>Note that the code generator does not yet support vector types with
5394 the <tt>fcmp</tt> instruction.</p>
5395
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5396</div>
5397
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5398<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5399<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5400 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5401</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5402
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5403<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5404
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5405<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5406<pre>
5407 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5408</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5409
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5410<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5411<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5412 SSA graph representing the function.</p>
5413
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5414<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5415<p>The type of the incoming values is specified with the first type field. After
5416 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5417 one pair for each predecessor basic block of the current block. Only values
5418 of <a href="#t_firstclass">first class</a> type may be used as the value
5419 arguments to the PHI node. Only labels may be used as the label
5420 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5421
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5422<p>There must be no non-phi instructions between the start of a basic block and
5423 the PHI instructions: i.e. PHI instructions must be first in a basic
5424 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5425
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5426<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5427 occur on the edge from the corresponding predecessor block to the current
5428 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5429 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5430
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5431<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5432<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5433 specified by the pair corresponding to the predecessor basic block that
5434 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5435
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5436<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5437<pre>
5438Loop: ; Infinite loop that counts from 0 on up...
5439 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5440 %nextindvar = add i32 %indvar, 1
5441 br label %Loop
5442</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5443
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5444</div>
5445
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5446<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5447<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5448 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5449</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5450
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5451<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5452
5453<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5454<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5455 &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>
5456
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5457 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5458</pre>
5459
5460<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5461<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5462 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5463
5464
5465<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5466<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5467 values indicating the condition, and two values of the
5468 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5469 vectors and the condition is a scalar, then entire vectors are selected, not
5470 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5471
5472<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5473<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5474 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5475
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5476<p>If the condition is a vector of i1, then the value arguments must be vectors
5477 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5478
5479<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5480<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5481 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5482</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5483
5484<p>Note that the code generator does not yet support conditions
5485 with vector type.</p>
5486
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5487</div>
5488
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5489<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5490<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5491 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5492</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5493
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5494<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5495
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5496<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5497<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5498 &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 Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5499</pre>
5500
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5501<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5502<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5503
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5504<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5505<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5506
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5507<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5508 <li>The optional "tail" marker indicates that the callee function does not
5509 access any allocas or varargs in the caller. Note that calls may be
5510 marked "tail" even if they do not occur before
5511 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5512 present, the function call is eligible for tail call optimization,
5513 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5514 optimized into a jump</a>. The code generator may optimize calls marked
5515 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5516 sibling call optimization</a> when the caller and callee have
5517 matching signatures, or 2) forced tail call optimization when the
5518 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5519 <ul>
5520 <li>Caller and callee both have the calling
5521 convention <tt>fastcc</tt>.</li>
5522 <li>The call is in tail position (ret immediately follows call and ret
5523 uses value of call or is void).</li>
5524 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5525 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5526 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5527 constraints are met.</a></li>
5528 </ul>
5529 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5530
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5531 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5532 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5533 defaults to using C calling conventions. The calling convention of the
5534 call must match the calling convention of the target function, or else the
5535 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5536
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5537 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5538 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5539 '<tt>inreg</tt>' attributes are valid here.</li>
5540
5541 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5542 type of the return value. Functions that return no value are marked
5543 <tt><a href="#t_void">void</a></tt>.</li>
5544
5545 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5546 being invoked. The argument types must match the types implied by this
5547 signature. This type can be omitted if the function is not varargs and if
5548 the function type does not return a pointer to a function.</li>
5549
5550 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5551 be invoked. In most cases, this is a direct function invocation, but
5552 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5553 to function value.</li>
5554
5555 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5556 signature argument types and parameter attributes. All arguments must be
5557 of <a href="#t_firstclass">first class</a> type. If the function
5558 signature indicates the function accepts a variable number of arguments,
5559 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5560
5561 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5562 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5563 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5564</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5565
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5566<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5567<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5568 a specified function, with its incoming arguments bound to the specified
5569 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5570 function, control flow continues with the instruction after the function
5571 call, and the return value of the function is bound to the result
5572 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5573
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5574<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5575<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5576 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5577 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5578 %X = tail call i32 @foo() <i>; yields i32</i>
5579 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5580 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5581
5582 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5583 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5584 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5585 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5586 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5587 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5588</pre>
5589
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5590<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5591standard C99 library as being the C99 library functions, and may perform
5592optimizations or generate code for them under that assumption. This is
5593something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5594freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5595
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5596</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5597
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5598<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5599<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5600 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5601</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5602
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5603<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5604
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5605<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5606<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5607 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5608</pre>
5609
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5610<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5611<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5612 the "variable argument" area of a function call. It is used to implement the
5613 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5614
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5615<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5616<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5617 argument. It returns a value of the specified argument type and increments
5618 the <tt>va_list</tt> to point to the next argument. The actual type
5619 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5620
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5621<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5622<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5623 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5624 to the next argument. For more information, see the variable argument
5625 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5626
5627<p>It is legal for this instruction to be called in a function which does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5628 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5629 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5630
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5631<p><tt>va_arg</tt> is an LLVM instruction instead of
5632 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5633 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5634
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5635<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5636<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5637
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5638<p>Note that the code generator does not yet fully support va_arg on many
5639 targets. Also, it does not currently support va_arg with aggregate types on
5640 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5641
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5642</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5643
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5644</div>
5645
5646</div>
5647
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5648<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5649<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5650<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5651
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5652<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5653
5654<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5655 well known names and semantics and are required to follow certain
5656 restrictions. Overall, these intrinsics represent an extension mechanism for
5657 the LLVM language that does not require changing all of the transformations
5658 in LLVM when adding to the language (or the bitcode reader/writer, the
5659 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5660
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5661<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5662 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5663 begin with this prefix. Intrinsic functions must always be external
5664 functions: you cannot define the body of intrinsic functions. Intrinsic
5665 functions may only be used in call or invoke instructions: it is illegal to
5666 take the address of an intrinsic function. Additionally, because intrinsic
5667 functions are part of the LLVM language, it is required if any are added that
5668 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5669
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5670<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5671 family of functions that perform the same operation but on different data
5672 types. Because LLVM can represent over 8 million different integer types,
5673 overloading is used commonly to allow an intrinsic function to operate on any
5674 integer type. One or more of the argument types or the result type can be
5675 overloaded to accept any integer type. Argument types may also be defined as
5676 exactly matching a previous argument's type or the result type. This allows
5677 an intrinsic function which accepts multiple arguments, but needs all of them
5678 to be of the same type, to only be overloaded with respect to a single
5679 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5680
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5681<p>Overloaded intrinsics will have the names of its overloaded argument types
5682 encoded into its function name, each preceded by a period. Only those types
5683 which are overloaded result in a name suffix. Arguments whose type is matched
5684 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5685 can take an integer of any width and returns an integer of exactly the same
5686 integer width. This leads to a family of functions such as
5687 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5688 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5689 suffix is required. Because the argument's type is matched against the return
5690 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5691
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5692<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5693 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5694
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5695<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5696<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5697 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5698</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5699
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5700<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5701
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5702<p>Variable argument support is defined in LLVM with
5703 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5704 intrinsic functions. These functions are related to the similarly named
5705 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5706
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5707<p>All of these functions operate on arguments that use a target-specific value
5708 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5709 not define what this type is, so all transformations should be prepared to
5710 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5711
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5712<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5713 instruction and the variable argument handling intrinsic functions are
5714 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5715
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5716<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5717define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5718 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5719 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5720 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5721 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5722
5723 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5724 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5725
5726 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5727 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5728 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5729 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5730 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5731
5732 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5733 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5734 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5735}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5736
5737declare void @llvm.va_start(i8*)
5738declare void @llvm.va_copy(i8*, i8*)
5739declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5740</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5741
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5742<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5743<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5744 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5745</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5746
5747
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5748<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5749
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5750<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5751<pre>
5752 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5753</pre>
5754
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5755<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5756<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5757 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5758
5759<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5760<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5761
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5762<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5763<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5764 macro available in C. In a target-dependent way, it initializes
5765 the <tt>va_list</tt> element to which the argument points, so that the next
5766 call to <tt>va_arg</tt> will produce the first variable argument passed to
5767 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5768 need to know the last argument of the function as the compiler can figure
5769 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5770
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5771</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5772
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5773<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5774<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5775 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5776</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5777
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5778<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5779
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5780<h5>Syntax:</h5>
5781<pre>
5782 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5783</pre>
5784
5785<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5786<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5787 which has been initialized previously
5788 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5789 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5790
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5791<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5792<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5793
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5794<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5795<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5796 macro available in C. In a target-dependent way, it destroys
5797 the <tt>va_list</tt> element to which the argument points. Calls
5798 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5799 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5800 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5801
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5802</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5803
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5804<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5805<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5806 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5807</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5808
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5809<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5810
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5811<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5812<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5813 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5814</pre>
5815
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5816<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5817<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5818 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5819
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5820<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5821<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5822 The second argument is a pointer to a <tt>va_list</tt> element to copy
5823 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5824
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5825<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5826<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5827 macro available in C. In a target-dependent way, it copies the
5828 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5829 element. This intrinsic is necessary because
5830 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5831 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5832
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5833</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5834
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5835</div>
5836
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5837<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5838<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5839 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5840</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5841
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5842<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5843
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5844<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5845Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5846intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5847roots on the stack</a>, as well as garbage collector implementations that
5848require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5849barriers. Front-ends for type-safe garbage collected languages should generate
5850these intrinsics to make use of the LLVM garbage collectors. For more details,
5851see <a href="GarbageCollection.html">Accurate Garbage Collection with
5852LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5853
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5854<p>The garbage collection intrinsics only operate on objects in the generic
5855 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5856
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5857<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5858<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5859 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5860</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5861
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5862<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5863
5864<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5865<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5866 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5867</pre>
5868
5869<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5870<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5871 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5872
5873<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5874<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5875 root pointer. The second pointer (which must be either a constant or a
5876 global value address) contains the meta-data to be associated with the
5877 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5878
5879<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5880<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5881 location. At compile-time, the code generator generates information to allow
5882 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5883 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5884 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5885
5886</div>
5887
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5888<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5889<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5890 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5891</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5892
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5893<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5894
5895<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5896<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5897 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5898</pre>
5899
5900<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5901<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5902 locations, allowing garbage collector implementations that require read
5903 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5904
5905<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5906<p>The second argument is the address to read from, which should be an address
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5907 allocated from the garbage collector. The first object is a pointer to the
5908 start of the referenced object, if needed by the language runtime (otherwise
5909 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5910
5911<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5912<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5913 instruction, but may be replaced with substantially more complex code by the
5914 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5915 may only be used in a function which <a href="#gc">specifies a GC
5916 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5917
5918</div>
5919
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5920<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5921<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5922 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5923</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5924
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5925<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5926
5927<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5928<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5929 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5930</pre>
5931
5932<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5933<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5934 locations, allowing garbage collector implementations that require write
5935 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5936
5937<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5938<p>The first argument is the reference to store, the second is the start of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5939 object to store it to, and the third is the address of the field of Obj to
5940 store to. If the runtime does not require a pointer to the object, Obj may
5941 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5942
5943<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5944<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5945 instruction, but may be replaced with substantially more complex code by the
5946 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5947 may only be used in a function which <a href="#gc">specifies a GC
5948 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5949
5950</div>
5951
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5952</div>
5953
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5954<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5955<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5956 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5957</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5958
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5959<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5960
5961<p>These intrinsics are provided by LLVM to expose special features that may
5962 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5963
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5964<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5965<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5966 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5967</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5968
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5969<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5970
5971<h5>Syntax:</h5>
5972<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5973 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5974</pre>
5975
5976<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5977<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5978 target-specific value indicating the return address of the current function
5979 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5980
5981<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5982<p>The argument to this intrinsic indicates which function to return the address
5983 for. Zero indicates the calling function, one indicates its caller, etc.
5984 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5985
5986<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5987<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5988 indicating the return address of the specified call frame, or zero if it
5989 cannot be identified. The value returned by this intrinsic is likely to be
5990 incorrect or 0 for arguments other than zero, so it should only be used for
5991 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5992
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5993<p>Note that calling this intrinsic does not prevent function inlining or other
5994 aggressive transformations, so the value returned may not be that of the
5995 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5996
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5997</div>
5998
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5999<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6000<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6001 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6002</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6003
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6004<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6005
6006<h5>Syntax:</h5>
6007<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6008 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6009</pre>
6010
6011<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6012<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6013 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6014
6015<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6016<p>The argument to this intrinsic indicates which function to return the frame
6017 pointer for. Zero indicates the calling function, one indicates its caller,
6018 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6019
6020<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6021<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6022 indicating the frame address of the specified call frame, or zero if it
6023 cannot be identified. The value returned by this intrinsic is likely to be
6024 incorrect or 0 for arguments other than zero, so it should only be used for
6025 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6026
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6027<p>Note that calling this intrinsic does not prevent function inlining or other
6028 aggressive transformations, so the value returned may not be that of the
6029 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6030
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6031</div>
6032
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6033<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6034<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6035 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6036</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6037
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6038<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6039
6040<h5>Syntax:</h5>
6041<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6042 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6043</pre>
6044
6045<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6046<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6047 of the function stack, for use
6048 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6049 useful for implementing language features like scoped automatic variable
6050 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6051
6052<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6053<p>This intrinsic returns a opaque pointer value that can be passed
6054 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6055 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6056 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6057 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6058 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6059 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6060
6061</div>
6062
6063<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6064<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6065 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6066</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6067
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6068<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6069
6070<h5>Syntax:</h5>
6071<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6072 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6073</pre>
6074
6075<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6076<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6077 the function stack to the state it was in when the
6078 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6079 executed. This is useful for implementing language features like scoped
6080 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6081
6082<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6083<p>See the description
6084 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6085
6086</div>
6087
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6088<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6089<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6090 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6091</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6092
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6093<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6094
6095<h5>Syntax:</h5>
6096<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6097 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;, i32 &lt;cache type&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6098</pre>
6099
6100<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6101<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6102 insert a prefetch instruction if supported; otherwise, it is a noop.
6103 Prefetches have no effect on the behavior of the program but can change its
6104 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6105
6106<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6107<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6108 specifier determining if the fetch should be for a read (0) or write (1),
6109 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6110 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6111 specifies whether the prefetch is performed on the data (1) or instruction (0)
6112 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6113 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6114
6115<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6116<p>This intrinsic does not modify the behavior of the program. In particular,
6117 prefetches cannot trap and do not produce a value. On targets that support
6118 this intrinsic, the prefetch can provide hints to the processor cache for
6119 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6120
6121</div>
6122
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6123<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6124<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6125 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6126</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6127
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6128<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6129
6130<h5>Syntax:</h5>
6131<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6132 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6133</pre>
6134
6135<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6136<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6137 Counter (PC) in a region of code to simulators and other tools. The method
6138 is target specific, but it is expected that the marker will use exported
6139 symbols to transmit the PC of the marker. The marker makes no guarantees
6140 that it will remain with any specific instruction after optimizations. It is
6141 possible that the presence of a marker will inhibit optimizations. The
6142 intended use is to be inserted after optimizations to allow correlations of
6143 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6144
6145<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6146<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6147
6148<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6149<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6150 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6151
6152</div>
6153
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6154<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6155<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6156 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6157</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6158
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6159<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6160
6161<h5>Syntax:</h5>
6162<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6163 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6164</pre>
6165
6166<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6167<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6168 counter register (or similar low latency, high accuracy clocks) on those
6169 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6170 should map to RPCC. As the backing counters overflow quickly (on the order
6171 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6172
6173<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6174<p>When directly supported, reading the cycle counter should not modify any
6175 memory. Implementations are allowed to either return a application specific
6176 value or a system wide value. On backends without support, this is lowered
6177 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6178
6179</div>
6180
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6181</div>
6182
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6183<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6184<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6185 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6186</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6187
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6188<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6189
6190<p>LLVM provides intrinsics for a few important standard C library functions.
6191 These intrinsics allow source-language front-ends to pass information about
6192 the alignment of the pointer arguments to the code generator, providing
6193 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6194
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6195<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6196<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6197 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6198</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6199
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6200<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6201
6202<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6203<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6204 integer bit width and for different address spaces. Not all targets support
6205 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6206
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6207<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6208 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6209 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6210 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6211 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6212</pre>
6213
6214<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6215<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6216 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6217
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6218<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6219 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6220 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6221
6222<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6223
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6224<p>The first argument is a pointer to the destination, the second is a pointer
6225 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6226 number of bytes to copy, the fourth argument is the alignment of the
6227 source and destination locations, and the fifth is a boolean indicating a
6228 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6229
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6230<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6231 then the caller guarantees that both the source and destination pointers are
6232 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6233
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6234<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6235 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6236 The detailed access behavior is not very cleanly specified and it is unwise
6237 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6238
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6239<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6240
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6241<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6242 source location to the destination location, which are not allowed to
6243 overlap. It copies "len" bytes of memory over. If the argument is known to
6244 be aligned to some boundary, this can be specified as the fourth argument,
6245 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6246
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6247</div>
6248
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6249<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6250<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6251 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6252</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6253
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6254<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6255
6256<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6257<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6258 width and for different address space. Not all targets support all bit
6259 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6260
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6261<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6262 declare void @llvm.memmove.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6263 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6264 declare void @llvm.memmove.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6265 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6266</pre>
6267
6268<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6269<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6270 source location to the destination location. It is similar to the
6271 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6272 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6273
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6274<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6275 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6276 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6277
6278<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6279
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6280<p>The first argument is a pointer to the destination, the second is a pointer
6281 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6282 number of bytes to copy, the fourth argument is the alignment of the
6283 source and destination locations, and the fifth is a boolean indicating a
6284 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6285
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6286<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6287 then the caller guarantees that the source and destination pointers are
6288 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6289
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6290<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6291 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6292 The detailed access behavior is not very cleanly specified and it is unwise
6293 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6294
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6295<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6296
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6297<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6298 source location to the destination location, which may overlap. It copies
6299 "len" bytes of memory over. If the argument is known to be aligned to some
6300 boundary, this can be specified as the fourth argument, otherwise it should
6301 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6302
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6303</div>
6304
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6305<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6306<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6307 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6308</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6309
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6310<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6311
6312<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6313<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6314 width and for different address spaces. However, not all targets support all
6315 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6316
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6317<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6318 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6319 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6320 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6321 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6322</pre>
6323
6324<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6325<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6326 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6327
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6328<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6329 intrinsic does not return a value and takes extra alignment/volatile
6330 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6331
6332<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6333<p>The first argument is a pointer to the destination to fill, the second is the
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6334 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6335 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6336 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6337
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6338<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6339 then the caller guarantees that the destination pointer is aligned to that
6340 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6341
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6342<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6343 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6344 The detailed access behavior is not very cleanly specified and it is unwise
6345 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6346
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6347<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6348<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6349 at the destination location. If the argument is known to be aligned to some
6350 boundary, this can be specified as the fourth argument, otherwise it should
6351 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6352
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6353</div>
6354
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6355<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6356<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6357 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6358</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6359
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6360<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6361
6362<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6363<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6364 floating point or vector of floating point type. Not all targets support all
6365 types however.</p>
6366
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6367<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6368 declare float @llvm.sqrt.f32(float %Val)
6369 declare double @llvm.sqrt.f64(double %Val)
6370 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6371 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6372 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6373</pre>
6374
6375<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6376<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6377 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6378 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6379 behavior for negative numbers other than -0.0 (which allows for better
6380 optimization, because there is no need to worry about errno being
6381 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6382
6383<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6384<p>The argument and return value are floating point numbers of the same
6385 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6386
6387<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6388<p>This function returns the sqrt of the specified operand if it is a
6389 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6390
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6391</div>
6392
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6393<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6394<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6395 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6396</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6397
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6398<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6399
6400<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6401<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6402 floating point or vector of floating point type. Not all targets support all
6403 types however.</p>
6404
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6405<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6406 declare float @llvm.powi.f32(float %Val, i32 %power)
6407 declare double @llvm.powi.f64(double %Val, i32 %power)
6408 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6409 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6410 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6411</pre>
6412
6413<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6414<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6415 specified (positive or negative) power. The order of evaluation of
6416 multiplications is not defined. When a vector of floating point type is
6417 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6418
6419<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6420<p>The second argument is an integer power, and the first is a value to raise to
6421 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6422
6423<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6424<p>This function returns the first value raised to the second power with an
6425 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6426
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6427</div>
6428
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6429<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6430<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6431 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6432</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6433
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6434<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6435
6436<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6437<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6438 floating point or vector of floating point type. Not all targets support all
6439 types however.</p>
6440
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6441<pre>
6442 declare float @llvm.sin.f32(float %Val)
6443 declare double @llvm.sin.f64(double %Val)
6444 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6445 declare fp128 @llvm.sin.f128(fp128 %Val)
6446 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6447</pre>
6448
6449<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6450<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6451
6452<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6453<p>The argument and return value are floating point numbers of the same
6454 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6455
6456<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6457<p>This function returns the sine of the specified operand, returning the same
6458 values as the libm <tt>sin</tt> functions would, and handles error conditions
6459 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6460
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6461</div>
6462
6463<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6464<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6465 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6466</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6467
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6468<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6469
6470<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6471<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6472 floating point or vector of floating point type. Not all targets support all
6473 types however.</p>
6474
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6475<pre>
6476 declare float @llvm.cos.f32(float %Val)
6477 declare double @llvm.cos.f64(double %Val)
6478 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6479 declare fp128 @llvm.cos.f128(fp128 %Val)
6480 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6481</pre>
6482
6483<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6484<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6485
6486<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6487<p>The argument and return value are floating point numbers of the same
6488 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6489
6490<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6491<p>This function returns the cosine of the specified operand, returning the same
6492 values as the libm <tt>cos</tt> functions would, and handles error conditions
6493 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6494
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6495</div>
6496
6497<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6498<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6499 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6500</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6501
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6502<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6503
6504<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6505<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6506 floating point or vector of floating point type. Not all targets support all
6507 types however.</p>
6508
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6509<pre>
6510 declare float @llvm.pow.f32(float %Val, float %Power)
6511 declare double @llvm.pow.f64(double %Val, double %Power)
6512 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6513 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6514 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6515</pre>
6516
6517<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6518<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6519 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6520
6521<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6522<p>The second argument is a floating point power, and the first is a value to
6523 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6524
6525<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6526<p>This function returns the first value raised to the second power, returning
6527 the same values as the libm <tt>pow</tt> functions would, and handles error
6528 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6529
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6530</div>
6531
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6532</div>
6533
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6534<!-- _______________________________________________________________________ -->
6535<h4>
6536 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6537</h4>
6538
6539<div>
6540
6541<h5>Syntax:</h5>
6542<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6543 floating point or vector of floating point type. Not all targets support all
6544 types however.</p>
6545
6546<pre>
6547 declare float @llvm.exp.f32(float %Val)
6548 declare double @llvm.exp.f64(double %Val)
6549 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6550 declare fp128 @llvm.exp.f128(fp128 %Val)
6551 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6552</pre>
6553
6554<h5>Overview:</h5>
6555<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6556
6557<h5>Arguments:</h5>
6558<p>The argument and return value are floating point numbers of the same
6559 type.</p>
6560
6561<h5>Semantics:</h5>
6562<p>This function returns the same values as the libm <tt>exp</tt> functions
6563 would, and handles error conditions in the same way.</p>
6564
6565</div>
6566
6567<!-- _______________________________________________________________________ -->
6568<h4>
6569 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6570</h4>
6571
6572<div>
6573
6574<h5>Syntax:</h5>
6575<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6576 floating point or vector of floating point type. Not all targets support all
6577 types however.</p>
6578
6579<pre>
6580 declare float @llvm.log.f32(float %Val)
6581 declare double @llvm.log.f64(double %Val)
6582 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6583 declare fp128 @llvm.log.f128(fp128 %Val)
6584 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6585</pre>
6586
6587<h5>Overview:</h5>
6588<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6589
6590<h5>Arguments:</h5>
6591<p>The argument and return value are floating point numbers of the same
6592 type.</p>
6593
6594<h5>Semantics:</h5>
6595<p>This function returns the same values as the libm <tt>log</tt> functions
6596 would, and handles error conditions in the same way.</p>
6597
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6598<h4>
6599 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6600</h4>
6601
6602<div>
6603
6604<h5>Syntax:</h5>
6605<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6606 floating point or vector of floating point type. Not all targets support all
6607 types however.</p>
6608
6609<pre>
6610 declare float @llvm.fma.f32(float %a, float %b, float %c)
6611 declare double @llvm.fma.f64(double %a, double %b, double %c)
6612 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6613 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6614 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6615</pre>
6616
6617<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]6618<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6619 operation.</p>
6620
6621<h5>Arguments:</h5>
6622<p>The argument and return value are floating point numbers of the same
6623 type.</p>
6624
6625<h5>Semantics:</h5>
6626<p>This function returns the same values as the libm <tt>fma</tt> functions
6627 would.</p>
6628
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6629</div>
6630
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6631<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6632<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6633 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6634</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6635
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6636<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6637
6638<p>LLVM provides intrinsics for a few important bit manipulation operations.
6639 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6640
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6641<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6642<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6643 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6644</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6645
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6646<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6647
6648<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6649<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6650 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6651
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6652<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6653 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6654 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6655 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6656</pre>
6657
6658<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6659<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6660 values with an even number of bytes (positive multiple of 16 bits). These
6661 are useful for performing operations on data that is not in the target's
6662 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6663
6664<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6665<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6666 and low byte of the input i16 swapped. Similarly,
6667 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6668 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6669 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6670 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6671 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6672 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6673
6674</div>
6675
6676<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6677<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6678 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6679</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6680
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6681<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6682
6683<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6684<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6685 width, or on any vector with integer elements. Not all targets support all
6686 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6687
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6688<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6689 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6690 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6691 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6692 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6693 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6694 declare &lt;2 x i32&gt; @llvm.ctpop.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6695</pre>
6696
6697<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6698<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6699 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6700
6701<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6702<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6703 integer type, or a vector with integer elements.
6704 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6705
6706<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6707<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6708 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6709
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6710</div>
6711
6712<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6713<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6714 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6715</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6716
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6717<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6718
6719<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6720<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6721 integer bit width, or any vector whose elements are integers. Not all
6722 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6723
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6724<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6725 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6726 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6727 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6728 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6729 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6730 declare &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src;gt)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6731</pre>
6732
6733<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6734<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6735 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6736
6737<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6738<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6739 integer type, or any vector type with integer element type.
6740 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6741
6742<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6743<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6744 zeros in a variable, or within each element of the vector if the operation
6745 is of vector type. If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6746 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6747
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6748</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6749
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6750<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6751<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6752 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6753</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6754
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6755<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6756
6757<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6758<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6759 integer bit width, or any vector of integer elements. Not all targets
6760 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6761
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6762<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6763 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6764 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6765 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6766 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6767 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6768 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6769</pre>
6770
6771<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6772<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6773 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6774
6775<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6776<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6777 integer type, or a vectory with integer element type.. The return type
6778 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6779
6780<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6781<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6782 zeros in a variable, or within each element of a vector.
6783 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6784 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6785
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6786</div>
6787
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6788</div>
6789
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6790<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6791<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6792 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6793</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6794
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6795<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6796
6797<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6798
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6799<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6800<h4>
6801 <a name="int_sadd_overflow">
6802 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6803 </a>
6804</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6805
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6806<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6807
6808<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6809<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6810 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6811
6812<pre>
6813 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6814 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6815 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6816</pre>
6817
6818<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6819<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6820 a signed addition of the two arguments, and indicate whether an overflow
6821 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6822
6823<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6824<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6825 be of integer types of any bit width, but they must have the same bit
6826 width. The second element of the result structure must be of
6827 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6828 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6829
6830<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6831<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6832 a signed addition of the two variables. They return a structure &mdash; the
6833 first element of which is the signed summation, and the second element of
6834 which is a bit specifying if the signed summation resulted in an
6835 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6836
6837<h5>Examples:</h5>
6838<pre>
6839 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6840 %sum = extractvalue {i32, i1} %res, 0
6841 %obit = extractvalue {i32, i1} %res, 1
6842 br i1 %obit, label %overflow, label %normal
6843</pre>
6844
6845</div>
6846
6847<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6848<h4>
6849 <a name="int_uadd_overflow">
6850 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6851 </a>
6852</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6853
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6854<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6855
6856<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6857<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6858 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6859
6860<pre>
6861 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6862 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6863 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6864</pre>
6865
6866<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6867<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6868 an unsigned addition of the two arguments, and indicate whether a carry
6869 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6870
6871<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6872<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6873 be of integer types of any bit width, but they must have the same bit
6874 width. The second element of the result structure must be of
6875 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6876 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6877
6878<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6879<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6880 an unsigned addition of the two arguments. They return a structure &mdash;
6881 the first element of which is the sum, and the second element of which is a
6882 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6883
6884<h5>Examples:</h5>
6885<pre>
6886 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6887 %sum = extractvalue {i32, i1} %res, 0
6888 %obit = extractvalue {i32, i1} %res, 1
6889 br i1 %obit, label %carry, label %normal
6890</pre>
6891
6892</div>
6893
6894<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6895<h4>
6896 <a name="int_ssub_overflow">
6897 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6898 </a>
6899</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6900
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6901<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6902
6903<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6904<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6905 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6906
6907<pre>
6908 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6909 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6910 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6911</pre>
6912
6913<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6914<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6915 a signed subtraction of the two arguments, and indicate whether an overflow
6916 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6917
6918<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6919<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6920 be of integer types of any bit width, but they must have the same bit
6921 width. The second element of the result structure must be of
6922 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6923 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6924
6925<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6926<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6927 a signed subtraction of the two arguments. They return a structure &mdash;
6928 the first element of which is the subtraction, and the second element of
6929 which is a bit specifying if the signed subtraction resulted in an
6930 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6931
6932<h5>Examples:</h5>
6933<pre>
6934 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6935 %sum = extractvalue {i32, i1} %res, 0
6936 %obit = extractvalue {i32, i1} %res, 1
6937 br i1 %obit, label %overflow, label %normal
6938</pre>
6939
6940</div>
6941
6942<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6943<h4>
6944 <a name="int_usub_overflow">
6945 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6946 </a>
6947</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6948
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6949<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6950
6951<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6952<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6953 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6954
6955<pre>
6956 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6957 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6958 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6959</pre>
6960
6961<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6962<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6963 an unsigned subtraction of the two arguments, and indicate whether an
6964 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6965
6966<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6967<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6968 be of integer types of any bit width, but they must have the same bit
6969 width. The second element of the result structure must be of
6970 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6971 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6972
6973<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6974<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6975 an unsigned subtraction of the two arguments. They return a structure &mdash;
6976 the first element of which is the subtraction, and the second element of
6977 which is a bit specifying if the unsigned subtraction resulted in an
6978 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6979
6980<h5>Examples:</h5>
6981<pre>
6982 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6983 %sum = extractvalue {i32, i1} %res, 0
6984 %obit = extractvalue {i32, i1} %res, 1
6985 br i1 %obit, label %overflow, label %normal
6986</pre>
6987
6988</div>
6989
6990<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6991<h4>
6992 <a name="int_smul_overflow">
6993 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6994 </a>
6995</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6996
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6997<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6998
6999<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7000<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7001 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7002
7003<pre>
7004 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7005 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7006 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7007</pre>
7008
7009<h5>Overview:</h5>
7010
7011<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7012 a signed multiplication of the two arguments, and indicate whether an
7013 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7014
7015<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7016<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7017 be of integer types of any bit width, but they must have the same bit
7018 width. The second element of the result structure must be of
7019 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7020 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7021
7022<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7023<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7024 a signed multiplication of the two arguments. They return a structure &mdash;
7025 the first element of which is the multiplication, and the second element of
7026 which is a bit specifying if the signed multiplication resulted in an
7027 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7028
7029<h5>Examples:</h5>
7030<pre>
7031 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7032 %sum = extractvalue {i32, i1} %res, 0
7033 %obit = extractvalue {i32, i1} %res, 1
7034 br i1 %obit, label %overflow, label %normal
7035</pre>
7036
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7037</div>
7038
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7039<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7040<h4>
7041 <a name="int_umul_overflow">
7042 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7043 </a>
7044</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7045
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7046<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7047
7048<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7049<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7050 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7051
7052<pre>
7053 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7054 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7055 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7056</pre>
7057
7058<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7059<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7060 a unsigned multiplication of the two arguments, and indicate whether an
7061 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7062
7063<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7064<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7065 be of integer types of any bit width, but they must have the same bit
7066 width. The second element of the result structure must be of
7067 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7068 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7069
7070<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7071<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7072 an unsigned multiplication of the two arguments. They return a structure
7073 &mdash; the first element of which is the multiplication, and the second
7074 element of which is a bit specifying if the unsigned multiplication resulted
7075 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7076
7077<h5>Examples:</h5>
7078<pre>
7079 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7080 %sum = extractvalue {i32, i1} %res, 0
7081 %obit = extractvalue {i32, i1} %res, 1
7082 br i1 %obit, label %overflow, label %normal
7083</pre>
7084
7085</div>
7086
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7087</div>
7088
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7089<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7090<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7091 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7092</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7093
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7094<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7095
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7096<p>Half precision floating point is a storage-only format. This means that it is
7097 a dense encoding (in memory) but does not support computation in the
7098 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7099
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7100<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7101 value as an i16, then convert it to float with <a
7102 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7103 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7104 double etc). To store the value back to memory, it is first converted to
7105 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7106 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7107 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7108
7109<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7110<h4>
7111 <a name="int_convert_to_fp16">
7112 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7113 </a>
7114</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7115
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7116<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7117
7118<h5>Syntax:</h5>
7119<pre>
7120 declare i16 @llvm.convert.to.fp16(f32 %a)
7121</pre>
7122
7123<h5>Overview:</h5>
7124<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7125 a conversion from single precision floating point format to half precision
7126 floating point format.</p>
7127
7128<h5>Arguments:</h5>
7129<p>The intrinsic function contains single argument - the value to be
7130 converted.</p>
7131
7132<h5>Semantics:</h5>
7133<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7134 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7135 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7136 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7137
7138<h5>Examples:</h5>
7139<pre>
7140 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7141 store i16 %res, i16* @x, align 2
7142</pre>
7143
7144</div>
7145
7146<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7147<h4>
7148 <a name="int_convert_from_fp16">
7149 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7150 </a>
7151</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7152
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7153<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7154
7155<h5>Syntax:</h5>
7156<pre>
7157 declare f32 @llvm.convert.from.fp16(i16 %a)
7158</pre>
7159
7160<h5>Overview:</h5>
7161<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7162 a conversion from half precision floating point format to single precision
7163 floating point format.</p>
7164
7165<h5>Arguments:</h5>
7166<p>The intrinsic function contains single argument - the value to be
7167 converted.</p>
7168
7169<h5>Semantics:</h5>
7170<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7171 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7172 precision floating point format. The input half-float value is represented by
7173 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7174
7175<h5>Examples:</h5>
7176<pre>
7177 %a = load i16* @x, align 2
7178 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7179</pre>
7180
7181</div>
7182
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7183</div>
7184
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7185<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7186<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7187 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7188</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7189
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7190<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7191
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7192<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7193 prefix), are described in
7194 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7195 Level Debugging</a> document.</p>
7196
7197</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7198
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7199<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7200<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7201 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7202</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7203
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7204<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7205
7206<p>The LLVM exception handling intrinsics (which all start with
7207 <tt>llvm.eh.</tt> prefix), are described in
7208 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7209 Handling</a> document.</p>
7210
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7211</div>
7212
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7213<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7214<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7215 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7216</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7217
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7218<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7219
7220<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7221 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7222 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7223 function pointer lacking the nest parameter - the caller does not need to
7224 provide a value for it. Instead, the value to use is stored in advance in a
7225 "trampoline", a block of memory usually allocated on the stack, which also
7226 contains code to splice the nest value into the argument list. This is used
7227 to implement the GCC nested function address extension.</p>
7228
7229<p>For example, if the function is
7230 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7231 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7232 follows:</p>
7233
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7234<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7235 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7236 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7237 %p = call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval)
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7238 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7239</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7240
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7241<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7242 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7243
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7244<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7245<h4>
7246 <a name="int_it">
7247 '<tt>llvm.init.trampoline</tt>' Intrinsic
7248 </a>
7249</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7250
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7251<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7252
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7253<h5>Syntax:</h5>
7254<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7255 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7256</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7257
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7258<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7259<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7260 function pointer suitable for executing it.</p>
7261
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7262<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7263<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7264 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7265 sufficiently aligned block of memory; this memory is written to by the
7266 intrinsic. Note that the size and the alignment are target-specific - LLVM
7267 currently provides no portable way of determining them, so a front-end that
7268 generates this intrinsic needs to have some target-specific knowledge.
7269 The <tt>func</tt> argument must hold a function bitcast to
7270 an <tt>i8*</tt>.</p>
7271
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7272<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7273<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7274 dependent code, turning it into a function. A pointer to this function is
7275 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7276 function pointer type</a> before being called. The new function's signature
7277 is the same as that of <tt>func</tt> with any arguments marked with
7278 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7279 is allowed, and it must be of pointer type. Calling the new function is
7280 equivalent to calling <tt>func</tt> with the same argument list, but
7281 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7282 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7283 by <tt>tramp</tt> is modified, then the effect of any later call to the
7284 returned function pointer is undefined.</p>
7285
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7286</div>
7287
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7288</div>
7289
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7290<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7291<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7292 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7293</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7294
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7295<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7296
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7297<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7298 hardware constructs for atomic operations and memory synchronization. This
7299 provides an interface to the hardware, not an interface to the programmer. It
7300 is aimed at a low enough level to allow any programming models or APIs
7301 (Application Programming Interfaces) which need atomic behaviors to map
7302 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7303 hardware provides a "universal IR" for source languages, it also provides a
7304 starting point for developing a "universal" atomic operation and
7305 synchronization IR.</p>
7306
7307<p>These do <em>not</em> form an API such as high-level threading libraries,
7308 software transaction memory systems, atomic primitives, and intrinsic
7309 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7310 application libraries. The hardware interface provided by LLVM should allow
7311 a clean implementation of all of these APIs and parallel programming models.
7312 No one model or paradigm should be selected above others unless the hardware
7313 itself ubiquitously does so.</p>
7314
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7315<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7316<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7317 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7318</h4>
7319
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7320<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7321<h5>Syntax:</h5>
7322<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7323 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 Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7324</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7325
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7326<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7327<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7328 specific pairs of memory access types.</p>
7329
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7330<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7331<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7332 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7333 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7334 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7335
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7336<ul>
7337 <li><tt>ll</tt>: load-load barrier</li>
7338 <li><tt>ls</tt>: load-store barrier</li>
7339 <li><tt>sl</tt>: store-load barrier</li>
7340 <li><tt>ss</tt>: store-store barrier</li>
7341 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7342</ul>
7343
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7344<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7345<p>This intrinsic causes the system to enforce some ordering constraints upon
7346 the loads and stores of the program. This barrier does not
7347 indicate <em>when</em> any events will occur, it only enforces
7348 an <em>order</em> in which they occur. For any of the specified pairs of load
7349 and store operations (f.ex. load-load, or store-load), all of the first
7350 operations preceding the barrier will complete before any of the second
7351 operations succeeding the barrier begin. Specifically the semantics for each
7352 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7353
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7354<ul>
7355 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7356 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7357 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7358 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7359 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7360 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7361 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7362 load after the barrier begins.</li>
7363</ul>
7364
7365<p>These semantics are applied with a logical "and" behavior when more than one
7366 is enabled in a single memory barrier intrinsic.</p>
7367
7368<p>Backends may implement stronger barriers than those requested when they do
7369 not support as fine grained a barrier as requested. Some architectures do
7370 not need all types of barriers and on such architectures, these become
7371 noops.</p>
7372
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7373<h5>Example:</h5>
7374<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7375%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7376%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7377 store i32 4, %ptr
7378
7379%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame]7380 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7381 <i>; guarantee the above finishes</i>
7382 store i32 8, %ptr <i>; before this begins</i>
7383</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7384
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7385</div>
7386
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7387<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7388<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7389 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7390</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7391
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7392<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7393
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7394<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7395<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7396 any integer bit width and for different address spaces. Not all targets
7397 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7398
7399<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7400 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7401 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7402 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7403 declare i64 @llvm.atomic.cmp.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7404</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7405
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7406<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7407<p>This loads a value in memory and compares it to a given value. If they are
7408 equal, it stores a new value into the memory.</p>
7409
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7410<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7411<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7412 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7413 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7414 this integer type. While any bit width integer may be used, targets may only
7415 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7416
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7417<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7418<p>This entire intrinsic must be executed atomically. It first loads the value
7419 in memory pointed to by <tt>ptr</tt> and compares it with the
7420 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7421 memory. The loaded value is yielded in all cases. This provides the
7422 equivalent of an atomic compare-and-swap operation within the SSA
7423 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7424
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7425<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7426<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7427%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7428%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7429 store i32 4, %ptr
7430
7431%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7432%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7433 <i>; yields {i32}:result1 = 4</i>
7434%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7435%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7436
7437%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7438%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7439 <i>; yields {i32}:result2 = 8</i>
7440%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7441
7442%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7443</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7444
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7445</div>
7446
7447<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7448<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7449 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7450</h4>
7451
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7452<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7453<h5>Syntax:</h5>
7454
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7455<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7456 integer bit width. Not all targets support all bit widths however.</p>
7457
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7458<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7459 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7460 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7461 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7462 declare i64 @llvm.atomic.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;val&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7463</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7464
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7465<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7466<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7467 the value from memory. It then stores the value in <tt>val</tt> in the memory
7468 at <tt>ptr</tt>.</p>
7469
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7470<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7471<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7472 the <tt>val</tt> argument and the result must be integers of the same bit
7473 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7474 integer type. The targets may only lower integer representations they
7475 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7476
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7477<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7478<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7479 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7480 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7481
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7482<h5>Examples:</h5>
7483<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7484%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7485%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7486 store i32 4, %ptr
7487
7488%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7489%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7490 <i>; yields {i32}:result1 = 4</i>
7491%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7492%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7493
7494%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7495%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7496 <i>; yields {i32}:result2 = 8</i>
7497
7498%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7499%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7500</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7501
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7502</div>
7503
7504<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7505<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7506 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7507</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7508
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7509<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7510
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7511<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7512<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7513 any integer bit width. Not all targets support all bit widths however.</p>
7514
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7515<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7516 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7517 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7518 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7519 declare i64 @llvm.atomic.load.add.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7520</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7521
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7522<h5>Overview:</h5>
7523<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7524 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7525
7526<h5>Arguments:</h5>
7527<p>The intrinsic takes two arguments, the first a pointer to an integer value
7528 and the second an integer value. The result is also an integer value. These
7529 integer types can have any bit width, but they must all have the same bit
7530 width. The targets may only lower integer representations they support.</p>
7531
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7532<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7533<p>This intrinsic does a series of operations atomically. It first loads the
7534 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7535 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7536
7537<h5>Examples:</h5>
7538<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7539%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7540%ptr = bitcast i8* %mallocP to i32*
7541 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7542%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7543 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7544%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7545 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7546%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7547 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7548%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7549</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7550
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7551</div>
7552
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7553<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7554<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7555 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7556</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7557
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7558<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7559
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7560<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7561<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7562 any integer bit width and for different address spaces. Not all targets
7563 support all bit widths however.</p>
7564
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7565<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7566 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7567 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7568 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7569 declare i64 @llvm.atomic.load.sub.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7570</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7571
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7572<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7573<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7574 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7575
7576<h5>Arguments:</h5>
7577<p>The intrinsic takes two arguments, the first a pointer to an integer value
7578 and the second an integer value. The result is also an integer value. These
7579 integer types can have any bit width, but they must all have the same bit
7580 width. The targets may only lower integer representations they support.</p>
7581
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7582<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7583<p>This intrinsic does a series of operations atomically. It first loads the
7584 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7585 result to <tt>ptr</tt>. It yields the original value stored
7586 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7587
7588<h5>Examples:</h5>
7589<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7590%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7591%ptr = bitcast i8* %mallocP to i32*
7592 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7593%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7594 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7595%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7596 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7597%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7598 <i>; yields {i32}:result3 = 2</i>
7599%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7600</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7601
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7602</div>
7603
7604<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7605<h4>
7606 <a name="int_atomic_load_and">
7607 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7608 </a>
7609 <br>
7610 <a name="int_atomic_load_nand">
7611 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7612 </a>
7613 <br>
7614 <a name="int_atomic_load_or">
7615 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7616 </a>
7617 <br>
7618 <a name="int_atomic_load_xor">
7619 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7620 </a>
7621</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7622
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7623<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7624
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7625<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7626<p>These are overloaded intrinsics. You can
7627 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7628 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7629 bit width and for different address spaces. Not all targets support all bit
7630 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7631
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7632<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7633 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7634 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7635 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7636 declare i64 @llvm.atomic.load.and.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7637</pre>
7638
7639<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7640 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7641 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7642 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7643 declare i64 @llvm.atomic.load.or.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7644</pre>
7645
7646<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7647 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7648 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7649 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7650 declare i64 @llvm.atomic.load.nand.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7651</pre>
7652
7653<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7654 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7655 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7656 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7657 declare i64 @llvm.atomic.load.xor.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7658</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7659
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7660<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7661<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7662 the value stored in memory at <tt>ptr</tt>. It yields the original value
7663 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7664
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7665<h5>Arguments:</h5>
7666<p>These intrinsics take two arguments, the first a pointer to an integer value
7667 and the second an integer value. The result is also an integer value. These
7668 integer types can have any bit width, but they must all have the same bit
7669 width. The targets may only lower integer representations they support.</p>
7670
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7671<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7672<p>These intrinsics does a series of operations atomically. They first load the
7673 value stored at <tt>ptr</tt>. They then do the bitwise
7674 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7675 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7676
7677<h5>Examples:</h5>
7678<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7679%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7680%ptr = bitcast i8* %mallocP to i32*
7681 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7682%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7683 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7684%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7685 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7686%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7687 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7688%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7689 <i>; yields {i32}:result3 = FF</i>
7690%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7691</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7692
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7693</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7694
7695<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7696<h4>
7697 <a name="int_atomic_load_max">
7698 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7699 </a>
7700 <br>
7701 <a name="int_atomic_load_min">
7702 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7703 </a>
7704 <br>
7705 <a name="int_atomic_load_umax">
7706 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7707 </a>
7708 <br>
7709 <a name="int_atomic_load_umin">
7710 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7711 </a>
7712</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7713
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7714<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7715
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7716<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7717<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7718 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7719 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7720 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7721
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7722<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7723 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7724 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7725 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7726 declare i64 @llvm.atomic.load.max.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7727</pre>
7728
7729<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7730 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7731 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7732 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7733 declare i64 @llvm.atomic.load.min.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7734</pre>
7735
7736<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7737 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7738 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7739 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7740 declare i64 @llvm.atomic.load.umax.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7741</pre>
7742
7743<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7744 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7745 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7746 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7747 declare i64 @llvm.atomic.load.umin.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7748</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7749
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7750<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7751<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7752 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7753 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7754
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7755<h5>Arguments:</h5>
7756<p>These intrinsics take two arguments, the first a pointer to an integer value
7757 and the second an integer value. The result is also an integer value. These
7758 integer types can have any bit width, but they must all have the same bit
7759 width. The targets may only lower integer representations they support.</p>
7760
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7761<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7762<p>These intrinsics does a series of operations atomically. They first load the
7763 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7764 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7765 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7766
7767<h5>Examples:</h5>
7768<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7769%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7770%ptr = bitcast i8* %mallocP to i32*
7771 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7772%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7773 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7774%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7775 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7776%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7777 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7778%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7779 <i>; yields {i32}:result3 = 8</i>
7780%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7781</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7782
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7783</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7784
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7785</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7786
7787<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7788<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7789 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7790</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7791
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7792<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7793
7794<p>This class of intrinsics exists to information about the lifetime of memory
7795 objects and ranges where variables are immutable.</p>
7796
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7797<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7798<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7799 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7800</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7801
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7802<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7803
7804<h5>Syntax:</h5>
7805<pre>
7806 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7807</pre>
7808
7809<h5>Overview:</h5>
7810<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7811 object's lifetime.</p>
7812
7813<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7814<p>The first argument is a constant integer representing the size of the
7815 object, or -1 if it is variable sized. The second argument is a pointer to
7816 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7817
7818<h5>Semantics:</h5>
7819<p>This intrinsic indicates that before this point in the code, the value of the
7820 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewycky8d336592009-10-27 16:56:58 +0000[diff] [blame]7821 never be used and has an undefined value. A load from the pointer that
7822 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7823 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7824
7825</div>
7826
7827<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7828<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7829 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7830</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7831
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7832<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7833
7834<h5>Syntax:</h5>
7835<pre>
7836 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7837</pre>
7838
7839<h5>Overview:</h5>
7840<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7841 object's lifetime.</p>
7842
7843<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7844<p>The first argument is a constant integer representing the size of the
7845 object, or -1 if it is variable sized. The second argument is a pointer to
7846 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7847
7848<h5>Semantics:</h5>
7849<p>This intrinsic indicates that after this point in the code, the value of the
7850 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7851 never be used and has an undefined value. Any stores into the memory object
7852 following this intrinsic may be removed as dead.
7853
7854</div>
7855
7856<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7857<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7858 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7859</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7860
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7861<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7862
7863<h5>Syntax:</h5>
7864<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]7865 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7866</pre>
7867
7868<h5>Overview:</h5>
7869<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7870 a memory object will not change.</p>
7871
7872<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7873<p>The first argument is a constant integer representing the size of the
7874 object, or -1 if it is variable sized. The second argument is a pointer to
7875 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7876
7877<h5>Semantics:</h5>
7878<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7879 the return value, the referenced memory location is constant and
7880 unchanging.</p>
7881
7882</div>
7883
7884<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7885<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7886 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7887</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7888
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7889<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7890
7891<h5>Syntax:</h5>
7892<pre>
7893 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7894</pre>
7895
7896<h5>Overview:</h5>
7897<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7898 a memory object are mutable.</p>
7899
7900<h5>Arguments:</h5>
7901<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7902 The second argument is a constant integer representing the size of the
7903 object, or -1 if it is variable sized and the third argument is a pointer
7904 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7905
7906<h5>Semantics:</h5>
7907<p>This intrinsic indicates that the memory is mutable again.</p>
7908
7909</div>
7910
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7911</div>
7912
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7913<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7914<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7915 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7916</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7917
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7918<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7919
7920<p>This class of intrinsics is designed to be generic and has no specific
7921 purpose.</p>
7922
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7923<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7924<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7925 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7926</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7927
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7928<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7929
7930<h5>Syntax:</h5>
7931<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7932 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7933</pre>
7934
7935<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7936<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7937
7938<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7939<p>The first argument is a pointer to a value, the second is a pointer to a
7940 global string, the third is a pointer to a global string which is the source
7941 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7942
7943<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7944<p>This intrinsic allows annotation of local variables with arbitrary strings.
7945 This can be useful for special purpose optimizations that want to look for
7946 these annotations. These have no other defined use, they are ignored by code
7947 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7948
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7949</div>
7950
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7951<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7952<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7953 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7954</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7955
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7956<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7957
7958<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7959<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7960 any integer bit width.</p>
7961
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7962<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7963 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7964 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7965 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7966 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7967 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7968</pre>
7969
7970<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7971<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7972
7973<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7974<p>The first argument is an integer value (result of some expression), the
7975 second is a pointer to a global string, the third is a pointer to a global
7976 string which is the source file name, and the last argument is the line
7977 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7978
7979<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7980<p>This intrinsic allows annotations to be put on arbitrary expressions with
7981 arbitrary strings. This can be useful for special purpose optimizations that
7982 want to look for these annotations. These have no other defined use, they
7983 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7984
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7985</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7986
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7987<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7988<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7989 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7990</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7991
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7992<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7993
7994<h5>Syntax:</h5>
7995<pre>
7996 declare void @llvm.trap()
7997</pre>
7998
7999<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8000<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8001
8002<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8003<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8004
8005<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8006<p>This intrinsics is lowered to the target dependent trap instruction. If the
8007 target does not have a trap instruction, this intrinsic will be lowered to
8008 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8009
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8010</div>
8011
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8012<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8013<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8014 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8015</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8016
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8017<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8018
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8019<h5>Syntax:</h5>
8020<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8021 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8022</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8023
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8024<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8025<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8026 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8027 ensure that it is placed on the stack before local variables.</p>
8028
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8029<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8030<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8031 arguments. The first argument is the value loaded from the stack
8032 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8033 that has enough space to hold the value of the guard.</p>
8034
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8035<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8036<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8037 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8038 stack. This is to ensure that if a local variable on the stack is
8039 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8040 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8041 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8042 function.</p>
8043
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8044</div>
8045
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8046<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8047<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8048 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8049</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8050
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8051<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8052
8053<h5>Syntax:</h5>
8054<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8055 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8056 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8057</pre>
8058
8059<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8060<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8061 the optimizers to determine at compile time whether a) an operation (like
8062 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8063 runtime check for overflow isn't necessary. An object in this context means
8064 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8065
8066<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8067<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8068 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8069 is a boolean 0 or 1. This argument determines whether you want the
8070 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8071 1, variables are not allowed.</p>
8072
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8073<h5>Semantics:</h5>
8074<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8075 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8076 depending on the <tt>type</tt> argument, if the size cannot be determined at
8077 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8078
8079</div>
8080
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8081</div>
8082
8083</div>
8084
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8085<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8086<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8087<address>
8088 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8089 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8090 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8091 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8092
8093 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8094 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8095 Last modified: $Date$
8096</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8097
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8098</body>
8099</html>