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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / c49b29ef5d4071cc4679d5560855f446f95919fc / . / 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.">
Daniel Dunbaradea4972012-04-19 20:20:34 +0000[diff] [blame]10 <link rel="stylesheet" href="_static/llvm.css" type="text/css">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]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>
Bill Wendlingf7f06102011-10-11 06:41:28 +0000[diff] [blame]38 <li><a href="#linkage_external">'<tt>external</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]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>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]57 <li><a href="#ordering">Atomic Memory Ordering Constraints</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]58 </ol>
59 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]60 <li><a href="#typesystem">Type System</a>
61 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]63 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]64 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]65 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]67 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]68 <li><a href="#t_void">Void Type</a></li>
69 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]70 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#t_derived">Derived Types</a>
74 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]75 <li><a href="#t_aggregate">Aggregate Types</a>
76 <ol>
77 <li><a href="#t_array">Array Type</a></li>
78 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]79 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]80 <li><a href="#t_vector">Vector Type</a></li>
81 </ol>
82 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]83 <li><a href="#t_function">Function Type</a></li>
84 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
87 </ol>
88 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
94 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]95 <li><a href="#poisonvalues">Poison Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Peter Collingbourne249d9532011-10-27 19:19:07 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a>
104 <ol>
105 <li><a href="#tbaa">'<tt>tbaa</tt>' Metadata</a></li>
Duncan Sands5e5c5f82012-04-14 12:36:06 +0000[diff] [blame]106 <li><a href="#fpmath">'<tt>fpmath</tt>' Metadata</a></li>
Rafael Espindola39dd3282012-03-24 00:14:51 +0000[diff] [blame]107 <li><a href="#range">'<tt>range</tt>' Metadata</a></li>
Peter Collingbourne249d9532011-10-27 19:19:07 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]110 </ol>
111 </li>
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]112 <li><a href="#module_flags">Module Flags Metadata</a>
113 <ol>
Bill Wendlingf7b367c2012-02-16 01:10:50 +0000[diff] [blame]114 <li><a href="#objc_gc_flags">Objective-C Garbage Collection Module Flags Metadata</a></li>
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]115 </ol>
116 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]117 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
118 <ol>
119 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]120 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
121 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]122 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
123 Global Variable</a></li>
124 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
125 Global Variable</a></li>
126 </ol>
127 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]128 <li><a href="#instref">Instruction Reference</a>
129 <ol>
130 <li><a href="#terminators">Terminator Instructions</a>
131 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
133 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]134 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]135 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]136 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]137 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]138 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]139 </ol>
140 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]141 <li><a href="#binaryops">Binary Operations</a>
142 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]143 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]144 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]145 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]146 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]147 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]148 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]149 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
150 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
151 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]152 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
153 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
154 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]157 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
158 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]159 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
160 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
161 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]162 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]163 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]164 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]165 </ol>
166 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]167 <li><a href="#vectorops">Vector Operations</a>
168 <ol>
169 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
170 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
171 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]172 </ol>
173 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]174 <li><a href="#aggregateops">Aggregate Operations</a>
175 <ol>
176 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
177 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
178 </ol>
179 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]180 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]181 <ol>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]182 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
183 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
184 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
185 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
186 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
187 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]188 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]189 </ol>
190 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]191 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]192 <ol>
193 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
194 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
195 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
196 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
197 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]198 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
199 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
200 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
201 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]202 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
203 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]204 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]205 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]206 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]207 <li><a href="#otherops">Other Operations</a>
208 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]209 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
210 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]211 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]212 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]213 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]214 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]215 <li><a href="#i_landingpad">'<tt>landingpad</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]216 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]217 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]218 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]219 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]220 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]221 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]222 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
223 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]224 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
225 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
226 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]227 </ol>
228 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]229 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
230 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]231 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
232 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
233 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]234 </ol>
235 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]236 <li><a href="#int_codegen">Code Generator Intrinsics</a>
237 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]238 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
239 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
240 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
241 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
242 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
243 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]244 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]245 </ol>
246 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]247 <li><a href="#int_libc">Standard C Library Intrinsics</a>
248 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]249 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
250 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
251 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
252 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
253 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]254 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
255 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
256 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]257 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
258 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]259 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]260 </ol>
261 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]262 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]263 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]264 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]265 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
266 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
267 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]268 </ol>
269 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]270 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
271 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]272 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
273 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
274 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
275 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
276 <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]277 <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]278 </ol>
279 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]280 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
281 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]282 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
283 <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]284 </ol>
285 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]286 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]287 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]288 <li><a href="#int_trampoline">Trampoline Intrinsics</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]289 <ol>
290 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]291 <li><a href="#int_at">'<tt>llvm.adjust.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]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>
Jakub Staszak8e1b12a2011-12-04 20:44:25 +0000[diff] [blame]296 <li><a href="#int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a></li>
297 <li><a href="#int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a></li>
298 <li><a href="#int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a></li>
299 <li><a href="#int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a></li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]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>
Dan Gohmana6063c62012-05-14 18:58:10 +0000[diff] [blame]310 <li><a href="#int_debugtrap">
311 '<tt>llvm.debugtrap</tt>' Intrinsic</a></li>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]312 <li><a href="#int_stackprotector">
313 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]314 <li><a href="#int_objectsize">
315 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Jakub Staszakb170e2d2011-12-04 18:29:26 +0000[diff] [blame]316 <li><a href="#int_expect">
317 '<tt>llvm.expect</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]318 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]319 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]320 </ol>
321 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]322</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
324<div class="doc_author">
325 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
326 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]327</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]328
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]329<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]330<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]331<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]332
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]333<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]334
335<p>This document is a reference manual for the LLVM assembly language. LLVM is
336 a Static Single Assignment (SSA) based representation that provides type
337 safety, low-level operations, flexibility, and the capability of representing
338 'all' high-level languages cleanly. It is the common code representation
339 used throughout all phases of the LLVM compilation strategy.</p>
340
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]341</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]342
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]343<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]344<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]345<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]346
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]347<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]348
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]349<p>The LLVM code representation is designed to be used in three different forms:
350 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
351 for fast loading by a Just-In-Time compiler), and as a human readable
352 assembly language representation. This allows LLVM to provide a powerful
353 intermediate representation for efficient compiler transformations and
354 analysis, while providing a natural means to debug and visualize the
355 transformations. The three different forms of LLVM are all equivalent. This
356 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]357
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]358<p>The LLVM representation aims to be light-weight and low-level while being
359 expressive, typed, and extensible at the same time. It aims to be a
360 "universal IR" of sorts, by being at a low enough level that high-level ideas
361 may be cleanly mapped to it (similar to how microprocessors are "universal
362 IR's", allowing many source languages to be mapped to them). By providing
363 type information, LLVM can be used as the target of optimizations: for
364 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]365 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]366 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]367
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]368<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]369<h4>
370 <a name="wellformed">Well-Formedness</a>
371</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]372
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]373<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]374
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]375<p>It is important to note that this document describes 'well formed' LLVM
376 assembly language. There is a difference between what the parser accepts and
377 what is considered 'well formed'. For example, the following instruction is
378 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]379
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]380<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]381%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]382</pre>
383
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]384<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
385 LLVM infrastructure provides a verification pass that may be used to verify
386 that an LLVM module is well formed. This pass is automatically run by the
387 parser after parsing input assembly and by the optimizer before it outputs
388 bitcode. The violations pointed out by the verifier pass indicate bugs in
389 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]390
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]391</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]392
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]393</div>
394
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]395<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]396
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]397<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]398<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]399<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]400
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]401<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]402
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]403<p>LLVM identifiers come in two basic types: global and local. Global
404 identifiers (functions, global variables) begin with the <tt>'@'</tt>
405 character. Local identifiers (register names, types) begin with
406 the <tt>'%'</tt> character. Additionally, there are three different formats
407 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]408
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]409<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]410 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]411 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
412 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
413 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
414 other characters in their names can be surrounded with quotes. Special
415 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
416 ASCII code for the character in hexadecimal. In this way, any character
417 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]418
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]419 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]420 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]422 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]423 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]424</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]425
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]426<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]427 don't need to worry about name clashes with reserved words, and the set of
428 reserved words may be expanded in the future without penalty. Additionally,
429 unnamed identifiers allow a compiler to quickly come up with a temporary
430 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]431
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]432<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]433 languages. There are keywords for different opcodes
434 ('<tt><a href="#i_add">add</a></tt>',
435 '<tt><a href="#i_bitcast">bitcast</a></tt>',
436 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
437 ('<tt><a href="#t_void">void</a></tt>',
438 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
439 reserved words cannot conflict with variable names, because none of them
440 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441
442<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]443 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]444
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]445<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]447<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]448%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449</pre>
450
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]451<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]452
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]453<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]454%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]455</pre>
456
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]457<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]459<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]460%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
461%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]462%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463</pre>
464
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]465<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
466 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]468<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]469 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]470 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]471
472 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]473 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]474
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]475 <li>Unnamed temporaries are numbered sequentially</li>
476</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]477
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]478<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]479 demonstrating instructions, we will follow an instruction with a comment that
480 defines the type and name of value produced. Comments are shown in italic
481 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]482
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]483</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]484
485<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]486<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]487<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]488<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]489<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]490<h3>
491 <a name="modulestructure">Module Structure</a>
492</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]493
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]494<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]495
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]496<p>LLVM programs are composed of <tt>Module</tt>s, each of which is a
497 translation unit of the input programs. Each module consists of functions,
498 global variables, and symbol table entries. Modules may be combined together
499 with the LLVM linker, which merges function (and global variable)
500 definitions, resolves forward declarations, and merges symbol table
501 entries. Here is an example of the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]502
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]503<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]504<i>; Declare the string constant as a global constant.</i>&nbsp;
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]505<a href="#identifiers">@.str</a> = <a href="#linkage_private">private</a>&nbsp;<a href="#globalvars">unnamed_addr</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00"&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]506
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]507<i>; External declaration of the puts function</i>&nbsp;
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]508<a href="#functionstructure">declare</a> i32 @puts(i8* <a href="#nocapture">nocapture</a>) <a href="#fnattrs">nounwind</a>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]509
510<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]511define i32 @main() { <i>; i32()* </i>&nbsp;
512 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]513 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.str, i64 0, i64 0
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]514
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]515 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]516 <a href="#i_call">call</a> i32 @puts(i8* %cast210)
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]517 <a href="#i_ret">ret</a> i32 0&nbsp;
518}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]519
520<i>; Named metadata</i>
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]521!1 = metadata !{i32 42}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]522!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]523</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]524
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]525<p>This example is made up of a <a href="#globalvars">global variable</a> named
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]526 "<tt>.str</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]527 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]528 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]529 "<tt>foo</tt>".</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]530
Bill Wendling4cc2be62012-03-14 08:07:43 +0000[diff] [blame]531<p>In general, a module is made up of a list of global values (where both
532 functions and global variables are global values). Global values are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]533 represented by a pointer to a memory location (in this case, a pointer to an
534 array of char, and a pointer to a function), and have one of the
535 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]536
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]537</div>
538
539<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]540<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]541 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]542</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]543
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]544<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]545
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]546<p>All Global Variables and Functions have one of the following types of
547 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]548
549<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]550 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]551 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
552 by objects in the current module. In particular, linking code into a
553 module with an private global value may cause the private to be renamed as
554 necessary to avoid collisions. Because the symbol is private to the
555 module, all references can be updated. This doesn't show up in any symbol
556 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]557
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]558 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]559 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
560 assembler and evaluated by the linker. Unlike normal strong symbols, they
561 are removed by the linker from the final linked image (executable or
562 dynamic library).</dd>
563
564 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
565 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
566 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
567 linker. The symbols are removed by the linker from the final linked image
568 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]569
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]570 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
571 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
572 of the object is not taken. For instance, functions that had an inline
573 definition, but the compiler decided not to inline it. Note,
574 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
575 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
576 visibility. The symbols are removed by the linker from the final linked
577 image (executable or dynamic library).</dd>
578
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]579 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]580 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]581 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
582 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]583
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]584 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]585 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]586 into the object file corresponding to the LLVM module. They exist to
587 allow inlining and other optimizations to take place given knowledge of
588 the definition of the global, which is known to be somewhere outside the
589 module. Globals with <tt>available_externally</tt> linkage are allowed to
590 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
591 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]592
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]593 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]594 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]595 the same name when linkage occurs. This can be used to implement
596 some forms of inline functions, templates, or other code which must be
597 generated in each translation unit that uses it, but where the body may
598 be overridden with a more definitive definition later. Unreferenced
599 <tt>linkonce</tt> globals are allowed to be discarded. Note that
600 <tt>linkonce</tt> linkage does not actually allow the optimizer to
601 inline the body of this function into callers because it doesn't know if
602 this definition of the function is the definitive definition within the
603 program or whether it will be overridden by a stronger definition.
604 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
605 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]606
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]607 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]608 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
609 <tt>linkonce</tt> linkage, except that unreferenced globals with
610 <tt>weak</tt> linkage may not be discarded. This is used for globals that
611 are declared "weak" in C source code.</dd>
612
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]613 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]614 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
615 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
616 global scope.
617 Symbols with "<tt>common</tt>" linkage are merged in the same way as
618 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]619 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]620 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]621 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
622 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]623
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]624
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]625 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]626 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]627 pointer to array type. When two global variables with appending linkage
628 are linked together, the two global arrays are appended together. This is
629 the LLVM, typesafe, equivalent of having the system linker append together
630 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]631
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]632 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]633 <dd>The semantics of this linkage follow the ELF object file model: the symbol
634 is weak until linked, if not linked, the symbol becomes null instead of
635 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]636
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]637 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
638 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]639 <dd>Some languages allow differing globals to be merged, such as two functions
640 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]641 that only equivalent globals are ever merged (the "one definition rule"
642 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]643 and <tt>weak_odr</tt> linkage types to indicate that the global will only
644 be merged with equivalent globals. These linkage types are otherwise the
645 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]646
Bill Wendling5c3a9f72011-11-04 20:40:41 +0000[diff] [blame]647 <dt><tt><b><a name="linkage_external">external</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]648 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]649 visible, meaning that it participates in linkage and can be used to
650 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]651</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]653<p>The next two types of linkage are targeted for Microsoft Windows platform
654 only. They are designed to support importing (exporting) symbols from (to)
655 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]656
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]657<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]658 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]659 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]660 or variable via a global pointer to a pointer that is set up by the DLL
661 exporting the symbol. On Microsoft Windows targets, the pointer name is
662 formed by combining <code>__imp_</code> and the function or variable
663 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]664
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]665 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]666 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]667 pointer to a pointer in a DLL, so that it can be referenced with the
668 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
669 name is formed by combining <code>__imp_</code> and the function or
670 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]671</dl>
672
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]673<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
674 another module defined a "<tt>.LC0</tt>" variable and was linked with this
675 one, one of the two would be renamed, preventing a collision. Since
676 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
677 declarations), they are accessible outside of the current module.</p>
678
679<p>It is illegal for a function <i>declaration</i> to have any linkage type
Bill Wendlingf7f06102011-10-11 06:41:28 +0000[diff] [blame]680 other than <tt>external</tt>, <tt>dllimport</tt>
681 or <tt>extern_weak</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]682
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]683<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]684 or <tt>weak_odr</tt> linkages.</p>
685
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]686</div>
687
688<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]689<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]690 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]691</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]692
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]693<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]694
695<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]696 and <a href="#i_invoke">invokes</a> can all have an optional calling
697 convention specified for the call. The calling convention of any pair of
698 dynamic caller/callee must match, or the behavior of the program is
699 undefined. The following calling conventions are supported by LLVM, and more
700 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]701
702<dl>
703 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]704 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]705 specified) matches the target C calling conventions. This calling
706 convention supports varargs function calls and tolerates some mismatch in
707 the declared prototype and implemented declaration of the function (as
708 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]709
710 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]711 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]712 (e.g. by passing things in registers). This calling convention allows the
713 target to use whatever tricks it wants to produce fast code for the
714 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]715 (Application Binary Interface).
716 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]717 when this or the GHC convention is used.</a> This calling convention
718 does not support varargs and requires the prototype of all callees to
719 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]720
721 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]722 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]723 as possible under the assumption that the call is not commonly executed.
724 As such, these calls often preserve all registers so that the call does
725 not break any live ranges in the caller side. This calling convention
726 does not support varargs and requires the prototype of all callees to
727 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]728
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]729 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
730 <dd>This calling convention has been implemented specifically for use by the
731 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
732 It passes everything in registers, going to extremes to achieve this by
733 disabling callee save registers. This calling convention should not be
734 used lightly but only for specific situations such as an alternative to
735 the <em>register pinning</em> performance technique often used when
736 implementing functional programming languages.At the moment only X86
737 supports this convention and it has the following limitations:
738 <ul>
739 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
740 floating point types are supported.</li>
741 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
742 6 floating point parameters.</li>
743 </ul>
744 This calling convention supports
745 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
746 requires both the caller and callee are using it.
747 </dd>
748
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]749 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]750 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]751 target-specific calling conventions to be used. Target specific calling
752 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]753</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]754
755<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]756 support Pascal conventions or any other well-known target-independent
757 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]758
759</div>
760
761<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]762<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]763 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]764</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]765
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]766<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]767
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]768<p>All Global Variables and Functions have one of the following visibility
769 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]770
771<dl>
772 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]773 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]774 that the declaration is visible to other modules and, in shared libraries,
775 means that the declared entity may be overridden. On Darwin, default
776 visibility means that the declaration is visible to other modules. Default
777 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]778
779 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]780 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]781 object if they are in the same shared object. Usually, hidden visibility
782 indicates that the symbol will not be placed into the dynamic symbol
783 table, so no other module (executable or shared library) can reference it
784 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]785
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]786 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]787 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]788 the dynamic symbol table, but that references within the defining module
789 will bind to the local symbol. That is, the symbol cannot be overridden by
790 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]791</dl>
792
793</div>
794
795<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]796<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]797 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]798</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]799
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]800<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]801
802<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]803 it easier to read the IR and make the IR more condensed (particularly when
804 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]805
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]806<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]807%mytype = type { %mytype*, i32 }
808</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]809
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]810<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]811 "<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]812 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]813
814<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]815 and that you can therefore specify multiple names for the same type. This
816 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
817 uses structural typing, the name is not part of the type. When printing out
818 LLVM IR, the printer will pick <em>one name</em> to render all types of a
819 particular shape. This means that if you have code where two different
820 source types end up having the same LLVM type, that the dumper will sometimes
821 print the "wrong" or unexpected type. This is an important design point and
822 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]823
824</div>
825
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]826<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]827<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]828 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]829</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]830
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]831<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]832
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]833<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]834 instead of run-time. Global variables may optionally be initialized, may
835 have an explicit section to be placed in, and may have an optional explicit
836 alignment specified. A variable may be defined as "thread_local", which
837 means that it will not be shared by threads (each thread will have a
838 separated copy of the variable). A variable may be defined as a global
839 "constant," which indicates that the contents of the variable
840 will <b>never</b> be modified (enabling better optimization, allowing the
841 global data to be placed in the read-only section of an executable, etc).
842 Note that variables that need runtime initialization cannot be marked
843 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]844
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]845<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
846 constant, even if the final definition of the global is not. This capability
847 can be used to enable slightly better optimization of the program, but
848 requires the language definition to guarantee that optimizations based on the
849 'constantness' are valid for the translation units that do not include the
850 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]851
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]852<p>As SSA values, global variables define pointer values that are in scope
853 (i.e. they dominate) all basic blocks in the program. Global variables
854 always define a pointer to their "content" type because they describe a
855 region of memory, and all memory objects in LLVM are accessed through
856 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]857
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]858<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
859 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]860 like this can be merged with other constants if they have the same
861 initializer. Note that a constant with significant address <em>can</em>
862 be merged with a <tt>unnamed_addr</tt> constant, the result being a
863 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]864
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]865<p>A global variable may be declared to reside in a target-specific numbered
866 address space. For targets that support them, address spaces may affect how
867 optimizations are performed and/or what target instructions are used to
868 access the variable. The default address space is zero. The address space
869 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]870
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]871<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]872 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]873
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]874<p>An explicit alignment may be specified for a global, which must be a power
875 of 2. If not present, or if the alignment is set to zero, the alignment of
876 the global is set by the target to whatever it feels convenient. If an
877 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]878 alignment. Targets and optimizers are not allowed to over-align the global
879 if the global has an assigned section. In this case, the extra alignment
880 could be observable: for example, code could assume that the globals are
881 densely packed in their section and try to iterate over them as an array,
882 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]883
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]884<p>For example, the following defines a global in a numbered address space with
885 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]886
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]887<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]888@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]889</pre>
890
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]891</div>
892
893
894<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]895<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]896 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]897</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]898
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]899<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]900
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]901<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]902 optional <a href="#linkage">linkage type</a>, an optional
903 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]904 <a href="#callingconv">calling convention</a>,
905 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]906 <a href="#paramattrs">parameter attribute</a> for the return type, a function
907 name, a (possibly empty) argument list (each with optional
908 <a href="#paramattrs">parameter attributes</a>), optional
909 <a href="#fnattrs">function attributes</a>, an optional section, an optional
910 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
911 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]912
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]913<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
914 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]915 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]916 <a href="#callingconv">calling convention</a>,
917 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]918 <a href="#paramattrs">parameter attribute</a> for the return type, a function
919 name, a possibly empty list of arguments, an optional alignment, and an
920 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]921
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]922<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]923 (Control Flow Graph) for the function. Each basic block may optionally start
924 with a label (giving the basic block a symbol table entry), contains a list
925 of instructions, and ends with a <a href="#terminators">terminator</a>
926 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]927
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]928<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]929 executed on entrance to the function, and it is not allowed to have
930 predecessor basic blocks (i.e. there can not be any branches to the entry
931 block of a function). Because the block can have no predecessors, it also
932 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]933
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]934<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]935 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]936
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]937<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]938 the alignment is set to zero, the alignment of the function is set by the
939 target to whatever it feels convenient. If an explicit alignment is
940 specified, the function is forced to have at least that much alignment. All
941 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]942
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]943<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
Bill Wendling5c3a9f72011-11-04 20:40:41 +0000[diff] [blame]944 be significant and two identical functions can be merged.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]945
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]946<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]947<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]948define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]949 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
950 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
951 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
952 [<a href="#gc">gc</a>] { ... }
953</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]954
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]955</div>
956
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]957<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]958<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]959 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]960</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]961
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]962<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]963
964<p>Aliases act as "second name" for the aliasee value (which can be either
965 function, global variable, another alias or bitcast of global value). Aliases
966 may have an optional <a href="#linkage">linkage type</a>, and an
967 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]968
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]969<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]970<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]971@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]972</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]973
974</div>
975
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]976<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]977<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]978 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]979</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]980
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]981<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]982
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]983<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]984 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]985 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]986
987<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]988<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]989; Some unnamed metadata nodes, which are referenced by the named metadata.
990!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]991!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]992!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]993; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]994!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]995</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]996
997</div>
998
999<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1000<h3>
1001 <a name="paramattrs">Parameter Attributes</a>
1002</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1003
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1004<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1005
1006<p>The return type and each parameter of a function type may have a set of
1007 <i>parameter attributes</i> associated with them. Parameter attributes are
1008 used to communicate additional information about the result or parameters of
1009 a function. Parameter attributes are considered to be part of the function,
1010 not of the function type, so functions with different parameter attributes
1011 can have the same function type.</p>
1012
1013<p>Parameter attributes are simple keywords that follow the type specified. If
1014 multiple parameter attributes are needed, they are space separated. For
1015 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1016
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1017<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1018declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1019declare i32 @atoi(i8 zeroext)
1020declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1021</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1022
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1023<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1024 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1025
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1026<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1027
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1028<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1029 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1030 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1031 should be zero-extended to the extent required by the target's ABI (which
1032 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1033 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1034
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1035 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1036 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1037 should be sign-extended to the extent required by the target's ABI (which
1038 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1039 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1040
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1041 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1042 <dd>This indicates that this parameter or return value should be treated in a
1043 special target-dependent fashion during while emitting code for a function
1044 call or return (usually, by putting it in a register as opposed to memory,
1045 though some targets use it to distinguish between two different kinds of
1046 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1047
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1048 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1049 <dd><p>This indicates that the pointer parameter should really be passed by
1050 value to the function. The attribute implies that a hidden copy of the
1051 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1052 is made between the caller and the callee, so the callee is unable to
Chris Lattneref097052012-05-30 00:40:23 +0000[diff] [blame]1053 modify the value in the caller. This attribute is only valid on LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1054 pointer arguments. It is generally used to pass structs and arrays by
1055 value, but is also valid on pointers to scalars. The copy is considered
1056 to belong to the caller not the callee (for example,
1057 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1058 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1059 values.</p>
1060
1061 <p>The byval attribute also supports specifying an alignment with
1062 the align attribute. It indicates the alignment of the stack slot to
1063 form and the known alignment of the pointer specified to the call site. If
1064 the alignment is not specified, then the code generator makes a
1065 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1066
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1067 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1068 <dd>This indicates that the pointer parameter specifies the address of a
1069 structure that is the return value of the function in the source program.
1070 This pointer must be guaranteed by the caller to be valid: loads and
1071 stores to the structure may be assumed by the callee to not to trap. This
1072 may only be applied to the first parameter. This is not a valid attribute
1073 for return values. </dd>
1074
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1075 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1076 <dd>This indicates that pointer values
1077 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1078 value do not alias pointer values which are not <i>based</i> on it,
1079 ignoring certain "irrelevant" dependencies.
1080 For a call to the parent function, dependencies between memory
1081 references from before or after the call and from those during the call
1082 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1083 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1084 The caller shares the responsibility with the callee for ensuring that
1085 these requirements are met.
1086 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1087 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1088<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1089 Note that this definition of <tt>noalias</tt> is intentionally
1090 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1091 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1092<br>
1093 For function return values, C99's <tt>restrict</tt> is not meaningful,
1094 while LLVM's <tt>noalias</tt> is.
1095 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1096
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1097 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1098 <dd>This indicates that the callee does not make any copies of the pointer
1099 that outlive the callee itself. This is not a valid attribute for return
1100 values.</dd>
1101
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1102 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1103 <dd>This indicates that the pointer parameter can be excised using the
1104 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1105 attribute for return values.</dd>
1106</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1107
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1108</div>
1109
1110<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1111<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1112 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1113</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1114
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1115<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1116
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1117<p>Each function may specify a garbage collector name, which is simply a
1118 string:</p>
1119
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1120<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1121define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1122</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1123
1124<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1125 collector which will cause the compiler to alter its output in order to
1126 support the named garbage collection algorithm.</p>
1127
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1128</div>
1129
1130<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1131<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1132 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1133</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1134
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1135<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1137<p>Function attributes are set to communicate additional information about a
1138 function. Function attributes are considered to be part of the function, not
1139 of the function type, so functions with different parameter attributes can
1140 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1141
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1142<p>Function attributes are simple keywords that follow the type specified. If
1143 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1144
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1145<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1146define void @f() noinline { ... }
1147define void @f() alwaysinline { ... }
1148define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1149define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1150</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1151
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1152<dl>
Kostya Serebryany164b86b2012-01-20 17:56:17 +0000[diff] [blame]1153 <dt><tt><b>address_safety</b></tt></dt>
1154 <dd>This attribute indicates that the address safety analysis
1155 is enabled for this function. </dd>
1156
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1157 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1158 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1159 the backend should forcibly align the stack pointer. Specify the
1160 desired alignment, which must be a power of two, in parentheses.
1161
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1162 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1163 <dd>This attribute indicates that the inliner should attempt to inline this
1164 function into callers whenever possible, ignoring any active inlining size
1165 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +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
Bill Wendling7b9e5392012-02-06 21:57:33 +0000[diff] [blame]1216 exceptions by calling the <tt>C++</tt> exception throwing methods.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1217
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1218 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1219 <dd>This attribute indicates that the function does not write through any
1220 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1221 arguments) or otherwise modify any state (e.g. memory, control registers,
1222 etc) visible to caller functions. It may dereference pointer arguments
1223 and read state that may be set in the caller. A readonly function always
1224 returns the same value (or unwinds an exception identically) when called
1225 with the same set of arguments and global state. It cannot unwind an
Bill Wendling7b9e5392012-02-06 21:57:33 +0000[diff] [blame]1226 exception by calling the <tt>C++</tt> exception throwing methods.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1227
Bill Wendling9bd5d042011-12-05 21:27:54 +0000[diff] [blame]1228 <dt><tt><b><a name="returns_twice">returns_twice</a></b></tt></dt>
1229 <dd>This attribute indicates that this function can return twice. The
1230 C <code>setjmp</code> is an example of such a function. The compiler
1231 disables some optimizations (like tail calls) in the caller of these
1232 functions.</dd>
1233
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1234 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1235 <dd>This attribute indicates that the function should emit a stack smashing
1236 protector. It is in the form of a "canary"&mdash;a random value placed on
1237 the stack before the local variables that's checked upon return from the
1238 function to see if it has been overwritten. A heuristic is used to
1239 determine if a function needs stack protectors or not.<br>
1240<br>
1241 If a function that has an <tt>ssp</tt> attribute is inlined into a
1242 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1243 function will have an <tt>ssp</tt> attribute.</dd>
1244
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1245 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1246 <dd>This attribute indicates that the function should <em>always</em> emit a
1247 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1248 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1249<br>
1250 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1251 function that doesn't have an <tt>sspreq</tt> attribute or which has
1252 an <tt>ssp</tt> attribute, then the resulting function will have
1253 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindolafbff0ec2011-07-25 15:27:59 +0000[diff] [blame]1254
1255 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1256 <dd>This attribute indicates that the ABI being targeted requires that
1257 an unwind table entry be produce for this function even if we can
1258 show that no exceptions passes by it. This is normally the case for
1259 the ELF x86-64 abi, but it can be disabled for some compilation
1260 units.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1261</dl>
1262
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1263</div>
1264
1265<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1266<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1267 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1268</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1269
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1270<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1271
1272<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1273 the GCC "file scope inline asm" blocks. These blocks are internally
1274 concatenated by LLVM and treated as a single unit, but may be separated in
1275 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1276
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1277<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1278module asm "inline asm code goes here"
1279module asm "more can go here"
1280</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1281
1282<p>The strings can contain any character by escaping non-printable characters.
1283 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]1284 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1285
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1286<p>The inline asm code is simply printed to the machine code .s file when
1287 assembly code is generated.</p>
1288
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1289</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1290
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1291<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1292<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1293 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1294</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1295
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1296<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1297
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1298<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1299 data is to be laid out in memory. The syntax for the data layout is
1300 simply:</p>
1301
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1302<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1303target datalayout = "<i>layout specification</i>"
1304</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1305
1306<p>The <i>layout specification</i> consists of a list of specifications
1307 separated by the minus sign character ('-'). Each specification starts with
1308 a letter and may include other information after the letter to define some
1309 aspect of the data layout. The specifications accepted are as follows:</p>
1310
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1311<dl>
1312 <dt><tt>E</tt></dt>
1313 <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]1314 bits with the most significance have the lowest address location.</dd>
1315
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1316 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1317 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1318 the bits with the least significance have the lowest address
1319 location.</dd>
1320
Lang Hamesbb5b3f32011-10-10 23:42:08 +0000[diff] [blame]1321 <dt><tt>S<i>size</i></tt></dt>
1322 <dd>Specifies the natural alignment of the stack in bits. Alignment promotion
1323 of stack variables is limited to the natural stack alignment to avoid
1324 dynamic stack realignment. The stack alignment must be a multiple of
Lang Hames5f119a62011-10-11 17:50:14 +0000[diff] [blame]1325 8-bits. If omitted, the natural stack alignment defaults to "unspecified",
1326 which does not prevent any alignment promotions.</dd>
Lang Hamesbb5b3f32011-10-10 23:42:08 +0000[diff] [blame]1327
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1328 <dt><tt>p:<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 <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1330 <i>preferred</i> alignments. All sizes are in bits. Specifying
1331 the <i>pref</i> alignment is optional. If omitted, the
1332 preceding <tt>:</tt> should be omitted too.</dd>
1333
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1334 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1335 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1336 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1337
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1338 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1339 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1340 <i>size</i>.</dd>
1341
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1342 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1343 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1344 <i>size</i>. Only values of <i>size</i> that are supported by the target
1345 will work. 32 (float) and 64 (double) are supported on all targets;
1346 80 or 128 (different flavors of long double) are also supported on some
1347 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1348
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1349 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1350 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1351 <i>size</i>.</dd>
1352
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1353 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1354 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1355 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1356
1357 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1358 <dd>This specifies a set of native integer widths for the target CPU
1359 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1360 "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]1361 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1362 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1363</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1364
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1365<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1366 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1367 specifications in the <tt>datalayout</tt> keyword. The default specifications
1368 are given in this list:</p>
1369
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1370<ul>
1371 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1372 <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]1373 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1374 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1375 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1376 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1377 <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]1378 alignment of 64-bits</li>
1379 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1380 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1381 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1382 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1383 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1384 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1385</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1386
1387<p>When LLVM is determining the alignment for a given type, it uses the
1388 following rules:</p>
1389
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1390<ol>
1391 <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]1392 specification is used.</li>
1393
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1394 <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]1395 smallest integer type that is larger than the bitwidth of the sought type
1396 is used. If none of the specifications are larger than the bitwidth then
1397 the the largest integer type is used. For example, given the default
1398 specifications above, the i7 type will use the alignment of i8 (next
1399 largest) while both i65 and i256 will use the alignment of i64 (largest
1400 specified).</li>
1401
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1402 <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]1403 largest vector type that is smaller than the sought vector type will be
1404 used as a fall back. This happens because &lt;128 x double&gt; can be
1405 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1406</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1407
Chris Lattner6509f502011-10-11 23:01:39 +0000[diff] [blame]1408<p>The function of the data layout string may not be what you expect. Notably,
1409 this is not a specification from the frontend of what alignment the code
1410 generator should use.</p>
1411
1412<p>Instead, if specified, the target data layout is required to match what the
1413 ultimate <em>code generator</em> expects. This string is used by the
1414 mid-level optimizers to
1415 improve code, and this only works if it matches what the ultimate code
1416 generator uses. If you would like to generate IR that does not embed this
1417 target-specific detail into the IR, then you don't have to specify the
1418 string. This will disable some optimizations that require precise layout
1419 information, but this also prevents those optimizations from introducing
1420 target specificity into the IR.</p>
1421
1422
1423
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1424</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1425
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1426<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1427<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1428 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1429</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1430
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1431<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1432
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1433<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1434with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1435is undefined. Pointer values are associated with address ranges
1436according to the following rules:</p>
1437
1438<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1439 <li>A pointer value is associated with the addresses associated with
1440 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1441 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1442 range of the variable's storage.</li>
1443 <li>The result value of an allocation instruction is associated with
1444 the address range of the allocated storage.</li>
1445 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1446 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1447 <li>An integer constant other than zero or a pointer value returned
1448 from a function not defined within LLVM may be associated with address
1449 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1450 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1451 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1452</ul>
1453
1454<p>A pointer value is <i>based</i> on another pointer value according
1455 to the following rules:</p>
1456
1457<ul>
1458 <li>A pointer value formed from a
1459 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1460 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1461 <li>The result value of a
1462 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1463 of the <tt>bitcast</tt>.</li>
1464 <li>A pointer value formed by an
1465 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1466 pointer values that contribute (directly or indirectly) to the
1467 computation of the pointer's value.</li>
1468 <li>The "<i>based</i> on" relationship is transitive.</li>
1469</ul>
1470
1471<p>Note that this definition of <i>"based"</i> is intentionally
1472 similar to the definition of <i>"based"</i> in C99, though it is
1473 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1474
1475<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1476<tt><a href="#i_load">load</a></tt> merely indicates the size and
1477alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1478interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1479<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1480and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1481
1482<p>Consequently, type-based alias analysis, aka TBAA, aka
1483<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1484LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1485additional information which specialized optimization passes may use
1486to implement type-based alias analysis.</p>
1487
1488</div>
1489
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1490<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1491<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1492 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1493</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1494
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1495<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1496
1497<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1498href="#i_store"><tt>store</tt></a>s, and <a
1499href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1500The optimizers must not change the number of volatile operations or change their
1501order of execution relative to other volatile operations. The optimizers
1502<i>may</i> change the order of volatile operations relative to non-volatile
1503operations. This is not Java's "volatile" and has no cross-thread
1504synchronization behavior.</p>
1505
1506</div>
1507
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1508<!-- ======================================================================= -->
1509<h3>
1510 <a name="memmodel">Memory Model for Concurrent Operations</a>
1511</h3>
1512
1513<div>
1514
1515<p>The LLVM IR does not define any way to start parallel threads of execution
1516or to register signal handlers. Nonetheless, there are platform-specific
1517ways to create them, and we define LLVM IR's behavior in their presence. This
1518model is inspired by the C++0x memory model.</p>
1519
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1520<p>For a more informal introduction to this model, see the
1521<a href="Atomics.html">LLVM Atomic Instructions and Concurrency Guide</a>.
1522
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1523<p>We define a <i>happens-before</i> partial order as the least partial order
1524that</p>
1525<ul>
1526 <li>Is a superset of single-thread program order, and</li>
1527 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1528 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1529 by platform-specific techniques, like pthread locks, thread
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1530 creation, thread joining, etc., and by atomic instructions.
1531 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1532 </li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1533</ul>
1534
1535<p>Note that program order does not introduce <i>happens-before</i> edges
1536between a thread and signals executing inside that thread.</p>
1537
1538<p>Every (defined) read operation (load instructions, memcpy, atomic
1539loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1540(defined) write operations (store instructions, atomic
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1541stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1542initialized globals are considered to have a write of the initializer which is
1543atomic and happens before any other read or write of the memory in question.
1544For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1545any write to the same byte, except:</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1546
1547<ul>
1548 <li>If <var>write<sub>1</sub></var> happens before
1549 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1550 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1551 does not see <var>write<sub>1</sub></var>.
Bill Wendling0246bb72011-07-31 06:45:03 +0000[diff] [blame]1552 <li>If <var>R<sub>byte</sub></var> happens before
1553 <var>write<sub>3</sub></var>, then <var>R<sub>byte</sub></var> does not
1554 see <var>write<sub>3</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1555</ul>
1556
1557<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1558<ul>
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1559 <li>If <var>R</var> is volatile, the result is target-dependent. (Volatile
1560 is supposed to give guarantees which can support
1561 <code>sig_atomic_t</code> in C/C++, and may be used for accesses to
1562 addresses which do not behave like normal memory. It does not generally
1563 provide cross-thread synchronization.)
1564 <li>Otherwise, if there is no write to the same byte that happens before
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1565 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1566 <tt>undef</tt> for that byte.
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1567 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1568 <var>R<sub>byte</sub></var> returns the value written by that
1569 write.</li>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1570 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1571 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1572 values written. See the <a href="#ordering">Atomic Memory Ordering
1573 Constraints</a> section for additional constraints on how the choice
1574 is made.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1575 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1576</ul>
1577
1578<p><var>R</var> returns the value composed of the series of bytes it read.
1579This implies that some bytes within the value may be <tt>undef</tt>
1580<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1581defines the semantics of the operation; it doesn't mean that targets will
1582emit more than one instruction to read the series of bytes.</p>
1583
1584<p>Note that in cases where none of the atomic intrinsics are used, this model
1585places only one restriction on IR transformations on top of what is required
1586for single-threaded execution: introducing a store to a byte which might not
Eli Friedman101c81d2011-08-02 01:15:34 +0000[diff] [blame]1587otherwise be stored is not allowed in general. (Specifically, in the case
1588where another thread might write to and read from an address, introducing a
1589store can change a load that may see exactly one write into a load that may
1590see multiple writes.)</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1591
1592<!-- FIXME: This model assumes all targets where concurrency is relevant have
1593a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1594none of the backends currently in the tree fall into this category; however,
1595there might be targets which care. If there are, we want a paragraph
1596like the following:
1597
1598Targets may specify that stores narrower than a certain width are not
1599available; on such a target, for the purposes of this model, treat any
1600non-atomic write with an alignment or width less than the minimum width
1601as if it writes to the relevant surrounding bytes.
1602-->
1603
1604</div>
1605
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1606<!-- ======================================================================= -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1607<h3>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1608 <a name="ordering">Atomic Memory Ordering Constraints</a>
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1609</h3>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1610
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1611<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1612
1613<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]1614<a href="#i_atomicrmw"><code>atomicrmw</code></a>,
1615<a href="#i_fence"><code>fence</code></a>,
1616<a href="#i_load"><code>atomic load</code></a>, and
Eli Friedman8fa281a2011-08-09 23:26:12 +0000[diff] [blame]1617<a href="#i_store"><code>atomic store</code></a>) take an ordering parameter
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1618that determines which other atomic instructions on the same address they
1619<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1620but are somewhat more colloquial. If these descriptions aren't precise enough,
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1621check those specs (see spec references in the
Nick Lewycky300a2632012-01-23 08:47:21 +0000[diff] [blame]1622<a href="Atomics.html#introduction">atomics guide</a>).
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1623<a href="#i_fence"><code>fence</code></a> instructions
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1624treat these orderings somewhat differently since they don't take an address.
1625See that instruction's documentation for details.</p>
1626
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1627<p>For a simpler introduction to the ordering constraints, see the
1628<a href="Atomics.html">LLVM Atomic Instructions and Concurrency Guide</a>.</p>
1629
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1630<dl>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1631<dt><code>unordered</code></dt>
1632<dd>The set of values that can be read is governed by the happens-before
1633partial order. A value cannot be read unless some operation wrote it.
1634This is intended to provide a guarantee strong enough to model Java's
1635non-volatile shared variables. This ordering cannot be specified for
1636read-modify-write operations; it is not strong enough to make them atomic
1637in any interesting way.</dd>
1638<dt><code>monotonic</code></dt>
1639<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1640total order for modifications by <code>monotonic</code> operations on each
1641address. All modification orders must be compatible with the happens-before
1642order. There is no guarantee that the modification orders can be combined to
1643a global total order for the whole program (and this often will not be
1644possible). The read in an atomic read-modify-write operation
1645(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1646<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1647reads the value in the modification order immediately before the value it
1648writes. If one atomic read happens before another atomic read of the same
1649address, the later read must see the same value or a later value in the
1650address's modification order. This disallows reordering of
1651<code>monotonic</code> (or stronger) operations on the same address. If an
1652address is written <code>monotonic</code>ally by one thread, and other threads
1653<code>monotonic</code>ally read that address repeatedly, the other threads must
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1654eventually see the write. This corresponds to the C++0x/C1x
1655<code>memory_order_relaxed</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1656<dt><code>acquire</code></dt>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1657<dd>In addition to the guarantees of <code>monotonic</code>,
Eli Friedmanc264b2f2011-08-24 20:28:39 +0000[diff] [blame]1658a <i>synchronizes-with</i> edge may be formed with a <code>release</code>
1659operation. This is intended to model C++'s <code>memory_order_acquire</code>.</dd>
1660<dt><code>release</code></dt>
1661<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1662writes a value which is subsequently read by an <code>acquire</code> operation,
1663it <i>synchronizes-with</i> that operation. (This isn't a complete
1664description; see the C++0x definition of a release sequence.) This corresponds
1665to the C++0x/C1x <code>memory_order_release</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1666<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1667<code>acquire</code> and <code>release</code> operation on its address.
1668This corresponds to the C++0x/C1x <code>memory_order_acq_rel</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1669<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1670<dd>In addition to the guarantees of <code>acq_rel</code>
1671(<code>acquire</code> for an operation which only reads, <code>release</code>
1672for an operation which only writes), there is a global total order on all
1673sequentially-consistent operations on all addresses, which is consistent with
1674the <i>happens-before</i> partial order and with the modification orders of
1675all the affected addresses. Each sequentially-consistent read sees the last
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1676preceding write to the same address in this global order. This corresponds
1677to the C++0x/C1x <code>memory_order_seq_cst</code> and Java volatile.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1678</dl>
1679
1680<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1681it only <i>synchronizes with</i> or participates in modification and seq_cst
1682total orderings with other operations running in the same thread (for example,
1683in signal handlers).</p>
1684
1685</div>
1686
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1687</div>
1688
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1689<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1690<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1691<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1692
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1693<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1694
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1695<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1696 intermediate representation. Being typed enables a number of optimizations
1697 to be performed on the intermediate representation directly, without having
1698 to do extra analyses on the side before the transformation. A strong type
1699 system makes it easier to read the generated code and enables novel analyses
1700 and transformations that are not feasible to perform on normal three address
1701 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1702
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1703<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1704<h3>
1705 <a name="t_classifications">Type Classifications</a>
1706</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1707
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1708<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1709
1710<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1711
1712<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1713 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1714 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1715 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1716 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1717 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1718 </tr>
1719 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1720 <td><a href="#t_floating">floating point</a></td>
Dan Gohmance163392011-12-17 00:04:22 +0000[diff] [blame]1721 <td><tt>half, float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1722 </tr>
1723 <tr>
1724 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1725 <td><a href="#t_integer">integer</a>,
1726 <a href="#t_floating">floating point</a>,
1727 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1728 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1729 <a href="#t_struct">structure</a>,
1730 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1731 <a href="#t_label">label</a>,
1732 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1733 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1734 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1735 <tr>
1736 <td><a href="#t_primitive">primitive</a></td>
1737 <td><a href="#t_label">label</a>,
1738 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1739 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1740 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1741 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1742 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1743 </tr>
1744 <tr>
1745 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1746 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1747 <a href="#t_function">function</a>,
1748 <a href="#t_pointer">pointer</a>,
1749 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1750 <a href="#t_vector">vector</a>,
1751 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1752 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1753 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1754 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1755</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1756
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1757<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1758 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1759 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1760
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1761</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1762
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1763<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1764<h3>
1765 <a name="t_primitive">Primitive Types</a>
1766</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1767
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1768<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1769
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1770<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1771 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1772
1773<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1774<h4>
1775 <a name="t_integer">Integer Type</a>
1776</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1777
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1778<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1779
1780<h5>Overview:</h5>
1781<p>The integer type is a very simple type that simply specifies an arbitrary
1782 bit width for the integer type desired. Any bit width from 1 bit to
1783 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1784
1785<h5>Syntax:</h5>
1786<pre>
1787 iN
1788</pre>
1789
1790<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1791 value.</p>
1792
1793<h5>Examples:</h5>
1794<table class="layout">
1795 <tr class="layout">
1796 <td class="left"><tt>i1</tt></td>
1797 <td class="left">a single-bit integer.</td>
1798 </tr>
1799 <tr class="layout">
1800 <td class="left"><tt>i32</tt></td>
1801 <td class="left">a 32-bit integer.</td>
1802 </tr>
1803 <tr class="layout">
1804 <td class="left"><tt>i1942652</tt></td>
1805 <td class="left">a really big integer of over 1 million bits.</td>
1806 </tr>
1807</table>
1808
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1809</div>
1810
1811<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1812<h4>
1813 <a name="t_floating">Floating Point Types</a>
1814</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1815
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1816<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1817
1818<table>
1819 <tbody>
1820 <tr><th>Type</th><th>Description</th></tr>
Dan Gohmance163392011-12-17 00:04:22 +0000[diff] [blame]1821 <tr><td><tt>half</tt></td><td>16-bit floating point value</td></tr>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1822 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1823 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1824 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1825 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1826 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1827 </tbody>
1828</table>
1829
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1830</div>
1831
1832<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1833<h4>
1834 <a name="t_x86mmx">X86mmx Type</a>
1835</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1836
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1837<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1838
1839<h5>Overview:</h5>
1840<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>
1841
1842<h5>Syntax:</h5>
1843<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1844 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1845</pre>
1846
1847</div>
1848
1849<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1850<h4>
1851 <a name="t_void">Void Type</a>
1852</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1853
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1854<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1855
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1856<h5>Overview:</h5>
1857<p>The void type does not represent any value and has no size.</p>
1858
1859<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1860<pre>
1861 void
1862</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1863
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1864</div>
1865
1866<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1867<h4>
1868 <a name="t_label">Label Type</a>
1869</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1870
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1871<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1872
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1873<h5>Overview:</h5>
1874<p>The label type represents code labels.</p>
1875
1876<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1877<pre>
1878 label
1879</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1880
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1881</div>
1882
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1883<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1884<h4>
1885 <a name="t_metadata">Metadata Type</a>
1886</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1887
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1888<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1889
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1890<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1891<p>The metadata type represents embedded metadata. No derived types may be
1892 created from metadata except for <a href="#t_function">function</a>
1893 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1894
1895<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1896<pre>
1897 metadata
1898</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1899
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1900</div>
1901
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1902</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1903
1904<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1905<h3>
1906 <a name="t_derived">Derived Types</a>
1907</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1908
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1909<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1910
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1911<p>The real power in LLVM comes from the derived types in the system. This is
1912 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1913 useful types. Each of these types contain one or more element types which
1914 may be a primitive type, or another derived type. For example, it is
1915 possible to have a two dimensional array, using an array as the element type
1916 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1917
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1918<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1919<h4>
1920 <a name="t_aggregate">Aggregate Types</a>
1921</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1922
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1923<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1924
1925<p>Aggregate Types are a subset of derived types that can contain multiple
Duncan Sands20536b52011-12-14 15:44:20 +0000[diff] [blame]1926 member types. <a href="#t_array">Arrays</a> and
1927 <a href="#t_struct">structs</a> are aggregate types.
1928 <a href="#t_vector">Vectors</a> are not considered to be aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1929
1930</div>
1931
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1932<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1933<h4>
1934 <a name="t_array">Array Type</a>
1935</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1936
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1937<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1938
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1939<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1940<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1941 sequentially in memory. The array type requires a size (number of elements)
1942 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1943
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1944<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1945<pre>
1946 [&lt;# elements&gt; x &lt;elementtype&gt;]
1947</pre>
1948
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1949<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1950 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1951
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1952<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1953<table class="layout">
1954 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1955 <td class="left"><tt>[40 x i32]</tt></td>
1956 <td class="left">Array of 40 32-bit integer values.</td>
1957 </tr>
1958 <tr class="layout">
1959 <td class="left"><tt>[41 x i32]</tt></td>
1960 <td class="left">Array of 41 32-bit integer values.</td>
1961 </tr>
1962 <tr class="layout">
1963 <td class="left"><tt>[4 x i8]</tt></td>
1964 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1965 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1966</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1967<p>Here are some examples of multidimensional arrays:</p>
1968<table class="layout">
1969 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1970 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1971 <td class="left">3x4 array of 32-bit integer values.</td>
1972 </tr>
1973 <tr class="layout">
1974 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1975 <td class="left">12x10 array of single precision floating point values.</td>
1976 </tr>
1977 <tr class="layout">
1978 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1979 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1980 </tr>
1981</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1982
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1983<p>There is no restriction on indexing beyond the end of the array implied by
1984 a static type (though there are restrictions on indexing beyond the bounds
1985 of an allocated object in some cases). This means that single-dimension
1986 'variable sized array' addressing can be implemented in LLVM with a zero
1987 length array type. An implementation of 'pascal style arrays' in LLVM could
1988 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1989
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1990</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1991
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1992<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1993<h4>
1994 <a name="t_function">Function Type</a>
1995</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1996
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1997<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1998
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1999<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2000<p>The function type can be thought of as a function signature. It consists of
2001 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]2002 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]2003
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2004<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2005<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]2006 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2007</pre>
2008
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2009<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]2010 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
2011 which indicates that the function takes a variable number of arguments.
2012 Variable argument functions can access their arguments with
2013 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2014 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]2015 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2016
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2017<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2018<table class="layout">
2019 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2020 <td class="left"><tt>i32 (i32)</tt></td>
2021 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2022 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2023 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2024 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]2025 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2026 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2027 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
2028 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2029 </td>
2030 </tr><tr class="layout">
2031 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2032 <td class="left">A vararg function that takes at least one
2033 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2034 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2035 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2036 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2037 </tr><tr class="layout">
2038 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]2039 <td class="left">A function taking an <tt>i32</tt>, returning a
2040 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2041 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2042 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2043</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2044
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2045</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2046
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2047<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2048<h4>
2049 <a name="t_struct">Structure Type</a>
2050</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2051
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2052<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2053
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2054<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2055<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2056 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]2057
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]2058<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2059 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2060 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2061 Structures in registers are accessed using the
2062 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2063 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2064
2065<p>Structures may optionally be "packed" structures, which indicate that the
2066 alignment of the struct is one byte, and that there is no padding between
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2067 the elements. In non-packed structs, padding between field types is inserted
2068 as defined by the TargetData string in the module, which is required to match
Chris Lattnere4617b02011-10-11 23:02:17 +0000[diff] [blame]2069 what the underlying code generator expects.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2070
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2071<p>Structures can either be "literal" or "identified". A literal structure is
2072 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) whereas identified
2073 types are always defined at the top level with a name. Literal types are
2074 uniqued by their contents and can never be recursive or opaque since there is
Chris Lattneraa175c32011-08-12 18:12:40 +0000[diff] [blame]2075 no way to write one. Identified types can be recursive, can be opaqued, and are
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2076 never uniqued.
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2077</p>
2078
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2079<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2080<pre>
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2081 %T1 = type { &lt;type list&gt; } <i>; Identified normal struct type</i>
2082 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Identified packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2083</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2084
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2085<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2086<table class="layout">
2087 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2088 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2089 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2090 </tr>
2091 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2092 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2093 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2094 second element is a <a href="#t_pointer">pointer</a> to a
2095 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2096 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2097 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2098 <tr class="layout">
2099 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2100 <td class="left">A packed struct known to be 5 bytes in size.</td>
2101 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]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>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2105
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2106<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2107<h4>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2108 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2109</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2110
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2111<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2112
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2113<h5>Overview:</h5>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2114<p>Opaque structure types are used to represent named structure types that do
2115 not have a body specified. This corresponds (for example) to the C notion of
2116 a forward declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2117
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2118<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2119<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2120 %X = type opaque
2121 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2122</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2123
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2124<h5>Examples:</h5>
2125<table class="layout">
2126 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2127 <td class="left"><tt>opaque</tt></td>
2128 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2129 </tr>
2130</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2131
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2132</div>
2133
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2134
2135
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2136<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2137<h4>
2138 <a name="t_pointer">Pointer Type</a>
2139</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2140
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2141<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2142
2143<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]2144<p>The pointer type is used to specify memory locations.
2145 Pointers are commonly used to reference objects in memory.</p>
2146
2147<p>Pointer types may have an optional address space attribute defining the
2148 numbered address space where the pointed-to object resides. The default
2149 address space is number zero. The semantics of non-zero address
2150 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2151
2152<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2153 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2154
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2155<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2156<pre>
2157 &lt;type&gt; *
2158</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2159
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2160<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2161<table class="layout">
2162 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2163 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2164 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2165 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2166 </tr>
2167 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]2168 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2169 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2170 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2171 <tt>i32</tt>.</td>
2172 </tr>
2173 <tr class="layout">
2174 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2175 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2176 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2177 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2178</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2179
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2180</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2181
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2182<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2183<h4>
2184 <a name="t_vector">Vector Type</a>
2185</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2186
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2187<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2188
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2189<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2190<p>A vector type is a simple derived type that represents a vector of elements.
2191 Vector types are used when multiple primitive data are operated in parallel
2192 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]2193 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2194 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2195
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2196<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2197<pre>
2198 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2199</pre>
2200
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]2201<p>The number of elements is a constant integer value larger than 0; elementtype
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]2202 may be any integer or floating point type, or a pointer to these types.
2203 Vectors of size zero are not allowed. </p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2204
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2205<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2206<table class="layout">
2207 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2208 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2209 <td class="left">Vector of 4 32-bit integer values.</td>
2210 </tr>
2211 <tr class="layout">
2212 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2213 <td class="left">Vector of 8 32-bit floating-point values.</td>
2214 </tr>
2215 <tr class="layout">
2216 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2217 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2218 </tr>
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]2219 <tr class="layout">
2220 <td class="left"><tt>&lt;4 x i64*&gt;</tt></td>
2221 <td class="left">Vector of 4 pointers to 64-bit integer values.</td>
2222 </tr>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2223</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2224
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2225</div>
2226
Bill Wendlingaf75f0c2011-07-31 06:47:33 +0000[diff] [blame]2227</div>
2228
NAKAMURA Takumi4b2e07a2011-10-31 13:04:26 +0000[diff] [blame]2229</div>
2230
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2231<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2232<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2233<!-- *********************************************************************** -->
2234
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2235<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2236
2237<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2238 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2239
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2240<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2241<h3>
2242 <a name="simpleconstants">Simple Constants</a>
2243</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2244
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2245<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2246
2247<dl>
2248 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2249 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2250 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2251
2252 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2253 <dd>Standard integers (such as '4') are constants of
2254 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2255 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2256
2257 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2258 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2259 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2260 notation (see below). The assembler requires the exact decimal value of a
2261 floating-point constant. For example, the assembler accepts 1.25 but
2262 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2263 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2264
2265 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2266 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2267 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2268</dl>
2269
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2270<p>The one non-intuitive notation for constants is the hexadecimal form of
2271 floating point constants. For example, the form '<tt>double
2272 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2273 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2274 constants are required (and the only time that they are generated by the
2275 disassembler) is when a floating point constant must be emitted but it cannot
2276 be represented as a decimal floating point number in a reasonable number of
2277 digits. For example, NaN's, infinities, and other special values are
2278 represented in their IEEE hexadecimal format so that assembly and disassembly
2279 do not cause any bits to change in the constants.</p>
2280
Dan Gohmance163392011-12-17 00:04:22 +0000[diff] [blame]2281<p>When using the hexadecimal form, constants of types half, float, and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2282 represented using the 16-digit form shown above (which matches the IEEE754
Dan Gohmance163392011-12-17 00:04:22 +0000[diff] [blame]2283 representation for double); half and float values must, however, be exactly
2284 representable as IEE754 half and single precision, respectively.
2285 Hexadecimal format is always used
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2286 for long double, and there are three forms of long double. The 80-bit format
2287 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2288 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2289 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2290 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2291 currently supported target uses this format. Long doubles will only work if
Tobias Grosser057beb82012-05-24 15:59:06 +0000[diff] [blame]2292 they match the long double format on your target. The IEEE 16-bit format
2293 (half precision) is represented by <tt>0xH</tt> followed by 4 hexadecimal
2294 digits. All hexadecimal formats are big-endian (sign bit at the left).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2295
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2296<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2297</div>
2298
2299<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2300<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2301<a name="aggregateconstants"></a> <!-- old anchor -->
2302<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2303</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2304
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2305<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2306
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2307<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2308 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2309
2310<dl>
2311 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2312 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2313 type definitions (a comma separated list of elements, surrounded by braces
2314 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2315 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2316 Structure constants must have <a href="#t_struct">structure type</a>, and
2317 the number and types of elements must match those specified by the
2318 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2319
2320 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2321 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2322 definitions (a comma separated list of elements, surrounded by square
2323 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2324 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2325 the number and types of elements must match those specified by the
2326 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2327
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2328 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2329 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2330 definitions (a comma separated list of elements, surrounded by
2331 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2332 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2333 have <a href="#t_vector">vector type</a>, and the number and types of
2334 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2335
2336 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2337 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2338 value to zero of <em>any</em> type, including scalar and
2339 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2340 This is often used to avoid having to print large zero initializers
2341 (e.g. for large arrays) and is always exactly equivalent to using explicit
2342 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2343
2344 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2345 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2346 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2347 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2348 be interpreted as part of the instruction stream, metadata is a place to
2349 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2350</dl>
2351
2352</div>
2353
2354<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2355<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2356 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2357</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2358
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2359<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2360
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2361<p>The addresses of <a href="#globalvars">global variables</a>
2362 and <a href="#functionstructure">functions</a> are always implicitly valid
2363 (link-time) constants. These constants are explicitly referenced when
2364 the <a href="#identifiers">identifier for the global</a> is used and always
2365 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2366 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2367
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2368<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2369@X = global i32 17
2370@Y = global i32 42
2371@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2372</pre>
2373
2374</div>
2375
2376<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2377<h3>
2378 <a name="undefvalues">Undefined Values</a>
2379</h3>
2380
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2381<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2382
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2383<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]2384 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2385 Undefined values may be of any type (other than '<tt>label</tt>'
2386 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2387
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2388<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2389 program is well defined no matter what value is used. This gives the
2390 compiler more freedom to optimize. Here are some examples of (potentially
2391 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2392
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2393
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2394<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2395 %A = add %X, undef
2396 %B = sub %X, undef
2397 %C = xor %X, undef
2398Safe:
2399 %A = undef
2400 %B = undef
2401 %C = undef
2402</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2403
2404<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]2405 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]2406
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2407<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2408 %A = or %X, undef
2409 %B = and %X, undef
2410Safe:
2411 %A = -1
2412 %B = 0
2413Unsafe:
2414 %A = undef
2415 %B = undef
2416</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2417
2418<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2419 For example, if <tt>%X</tt> has a zero bit, then the output of the
2420 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2421 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2422 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2423 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2424 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2425 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2426 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2427
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2428<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2429 %A = select undef, %X, %Y
2430 %B = select undef, 42, %Y
2431 %C = select %X, %Y, undef
2432Safe:
2433 %A = %X (or %Y)
2434 %B = 42 (or %Y)
2435 %C = %Y
2436Unsafe:
2437 %A = undef
2438 %B = undef
2439 %C = undef
2440</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2441
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2442<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2443 branch) conditions can go <em>either way</em>, but they have to come from one
2444 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2445 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2446 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2447 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2448 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2449 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2450
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2451<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2452 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2453
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2454 %B = undef
2455 %C = xor %B, %B
2456
2457 %D = undef
2458 %E = icmp lt %D, 4
2459 %F = icmp gte %D, 4
2460
2461Safe:
2462 %A = undef
2463 %B = undef
2464 %C = undef
2465 %D = undef
2466 %E = undef
2467 %F = undef
2468</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2469
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2470<p>This example points out that two '<tt>undef</tt>' operands are not
2471 necessarily the same. This can be surprising to people (and also matches C
2472 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2473 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2474 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2475 its value over its "live range". This is true because the variable doesn't
2476 actually <em>have a live range</em>. Instead, the value is logically read
2477 from arbitrary registers that happen to be around when needed, so the value
2478 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2479 need to have the same semantics or the core LLVM "replace all uses with"
2480 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2481
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2482<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2483 %A = fdiv undef, %X
2484 %B = fdiv %X, undef
2485Safe:
2486 %A = undef
2487b: unreachable
2488</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2489
2490<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2491 value</em> and <em>undefined behavior</em>. An undefined value (like
2492 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2493 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2494 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2495 defined on SNaN's. However, in the second example, we can make a more
2496 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2497 arbitrary value, we are allowed to assume that it could be zero. Since a
2498 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2499 the operation does not execute at all. This allows us to delete the divide and
2500 all code after it. Because the undefined operation "can't happen", the
2501 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2502
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2503<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2504a: store undef -> %X
2505b: store %X -> undef
2506Safe:
2507a: &lt;deleted&gt;
2508b: unreachable
2509</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2510
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2511<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2512 undefined value can be assumed to not have any effect; we can assume that the
2513 value is overwritten with bits that happen to match what was already there.
2514 However, a store <em>to</em> an undefined location could clobber arbitrary
2515 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2516
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2517</div>
2518
2519<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2520<h3>
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]2521 <a name="poisonvalues">Poison Values</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2522</h3>
2523
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2524<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2525
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]2526<p>Poison values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmane1a29842011-12-06 03:35:58 +0000[diff] [blame]2527 they also represent the fact that an instruction or constant expression which
2528 cannot evoke side effects has nevertheless detected a condition which results
2529 in undefined behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2530
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]2531<p>There is currently no way of representing a poison value in the IR; they
Dan Gohman855abed2010-05-03 14:51:43 +0000[diff] [blame]2532 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2533 <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]2534
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]2535<p>Poison value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2536
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2537<ul>
2538<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2539 their operands.</li>
2540
2541<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2542 to their dynamic predecessor basic block.</li>
2543
2544<li>Function arguments depend on the corresponding actual argument values in
2545 the dynamic callers of their functions.</li>
2546
2547<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2548 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2549 control back to them.</li>
2550
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2551<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
Bill Wendling7b9e5392012-02-06 21:57:33 +0000[diff] [blame]2552 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_resume"><tt>resume</tt></a>,
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2553 or exception-throwing call instructions that dynamically transfer control
2554 back to them.</li>
2555
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2556<li>Non-volatile loads and stores depend on the most recent stores to all of the
2557 referenced memory addresses, following the order in the IR
2558 (including loads and stores implied by intrinsics such as
2559 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2560
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2561<!-- TODO: In the case of multiple threads, this only applies if the store
2562 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2563
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2564<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2565
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2566<li>An instruction with externally visible side effects depends on the most
2567 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2568 the order in the IR. (This includes
2569 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2570
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2571<li>An instruction <i>control-depends</i> on a
2572 <a href="#terminators">terminator instruction</a>
2573 if the terminator instruction has multiple successors and the instruction
2574 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2575 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2576
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2577<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2578 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2579 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2580 successor.</li>
2581
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2582<li>Dependence is transitive.</li>
2583
2584</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2585
Dan Gohmane1a29842011-12-06 03:35:58 +0000[diff] [blame]2586<p>Poison Values have the same behavior as <a href="#undefvalues">undef values</a>,
2587 with the additional affect that any instruction which has a <i>dependence</i>
2588 on a poison value has undefined behavior.</p>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2589
2590<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2591
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2592<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2593entry:
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]2594 %poison = sub nuw i32 0, 1 ; Results in a poison value.
Dan Gohmane1a29842011-12-06 03:35:58 +0000[diff] [blame]2595 %still_poison = and i32 %poison, 0 ; 0, but also poison.
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]2596 %poison_yet_again = getelementptr i32* @h, i32 %still_poison
Dan Gohmane1a29842011-12-06 03:35:58 +0000[diff] [blame]2597 store i32 0, i32* %poison_yet_again ; memory at @h[0] is poisoned
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2598
Dan Gohmane1a29842011-12-06 03:35:58 +0000[diff] [blame]2599 store i32 %poison, i32* @g ; Poison value stored to memory.
2600 %poison2 = load i32* @g ; Poison value loaded back from memory.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2601
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]2602 store volatile i32 %poison, i32* @g ; External observation; undefined behavior.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2603
2604 %narrowaddr = bitcast i32* @g to i16*
2605 %wideaddr = bitcast i32* @g to i64*
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]2606 %poison3 = load i16* %narrowaddr ; Returns a poison value.
2607 %poison4 = load i64* %wideaddr ; Returns a poison value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2608
Dan Gohman5cdc51e2011-12-06 03:31:14 +0000[diff] [blame]2609 %cmp = icmp slt i32 %poison, 0 ; Returns a poison value.
2610 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2611
2612true:
Dan Gohman5cdc51e2011-12-06 03:31:14 +0000[diff] [blame]2613 store volatile i32 0, i32* @g ; This is control-dependent on %cmp, so
2614 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2615 br label %end
2616
2617end:
2618 %p = phi i32 [ 0, %entry ], [ 1, %true ]
Dan Gohman5cdc51e2011-12-06 03:31:14 +0000[diff] [blame]2619 ; Both edges into this PHI are
2620 ; control-dependent on %cmp, so this
2621 ; always results in a poison value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2622
Dan Gohman5cdc51e2011-12-06 03:31:14 +0000[diff] [blame]2623 store volatile i32 0, i32* @g ; This would depend on the store in %true
2624 ; if %cmp is true, or the store in %entry
2625 ; otherwise, so this is undefined behavior.
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2626
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2627 br i1 %cmp, label %second_true, label %second_end
Dan Gohman5cdc51e2011-12-06 03:31:14 +0000[diff] [blame]2628 ; The same branch again, but this time the
2629 ; true block doesn't have side effects.
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2630
2631second_true:
2632 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2633 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2634
2635second_end:
Dan Gohman5cdc51e2011-12-06 03:31:14 +0000[diff] [blame]2636 store volatile i32 0, i32* @g ; This time, the instruction always depends
2637 ; on the store in %end. Also, it is
2638 ; control-equivalent to %end, so this is
Dan Gohmane1a29842011-12-06 03:35:58 +0000[diff] [blame]2639 ; well-defined (ignoring earlier undefined
2640 ; behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2641</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2642
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2643</div>
2644
2645<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2646<h3>
2647 <a name="blockaddress">Addresses of Basic Blocks</a>
2648</h3>
2649
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2650<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2651
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2652<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2653
2654<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2655 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2656 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2657
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2658<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2659 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2660 comparisons against null. Pointer equality tests between labels addresses
2661 results in undefined behavior &mdash; though, again, comparison against null
2662 is ok, and no label is equal to the null pointer. This may be passed around
2663 as an opaque pointer sized value as long as the bits are not inspected. This
2664 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2665 long as the original value is reconstituted before the <tt>indirectbr</tt>
2666 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2667
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2668<p>Finally, some targets may provide defined semantics when using the value as
2669 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2670
2671</div>
2672
2673
2674<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2675<h3>
2676 <a name="constantexprs">Constant Expressions</a>
2677</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2678
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2679<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2680
2681<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2682 to be used as constants. Constant expressions may be of
2683 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2684 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2685 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2686
2687<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2688 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2689 <dd>Truncate a constant to another type. The bit size of CST must be larger
2690 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2691
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2692 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2693 <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]2694 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2695
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2696 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2697 <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]2698 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2699
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2700 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2701 <dd>Truncate a floating point constant to another floating point type. The
2702 size of CST must be larger than the size of TYPE. Both types must be
2703 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2704
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2705 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2706 <dd>Floating point extend a constant to another type. The size of CST must be
2707 smaller or equal to the size of TYPE. Both types must be floating
2708 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2709
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2710 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2711 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2712 constant. TYPE must be a scalar or vector integer type. CST must be of
2713 scalar or vector floating point type. Both CST and TYPE must be scalars,
2714 or vectors of the same number of elements. If the value won't fit in the
2715 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2716
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2717 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2718 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2719 constant. TYPE must be a scalar or vector integer type. CST must be of
2720 scalar or vector floating point type. Both CST and TYPE must be scalars,
2721 or vectors of the same number of elements. If the value won't fit in the
2722 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2723
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2724 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2725 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2726 constant. TYPE must be a scalar or vector floating point type. CST must be
2727 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2728 vectors of the same number of elements. If the value won't fit in the
2729 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2730
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2731 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2732 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2733 constant. TYPE must be a scalar or vector floating point type. CST must be
2734 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2735 vectors of the same number of elements. If the value won't fit in the
2736 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2737
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2738 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2739 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2740 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2741 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2742 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2743
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2744 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2745 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2746 type. CST must be of integer type. The CST value is zero extended,
2747 truncated, or unchanged to make it fit in a pointer size. This one is
2748 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2749
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2750 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2751 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2752 are the same as those for the <a href="#i_bitcast">bitcast
2753 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2754
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2755 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2756 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2757 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2758 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2759 instruction, the index list may have zero or more indexes, which are
2760 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2761
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2762 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2763 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2764
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2765 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2766 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2767
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2768 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2769 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2770
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2771 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2772 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2773 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2774
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2775 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2776 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2777 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2778
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2779 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2780 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2781 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2782
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2783 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2784 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2785 constants. The index list is interpreted in a similar manner as indices in
2786 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2787 index value must be specified.</dd>
2788
2789 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2790 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2791 constants. The index list is interpreted in a similar manner as indices in
2792 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2793 index value must be specified.</dd>
2794
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2795 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2796 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2797 be any of the <a href="#binaryops">binary</a>
2798 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2799 on operands are the same as those for the corresponding instruction
2800 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2801</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2802
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2803</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2804
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2805</div>
2806
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2807<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2808<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2809<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2810<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2811<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2812<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2813<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2814</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2815
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2816<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2817
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2818<p>LLVM supports inline assembler expressions (as opposed
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame]2819 to <a href="#moduleasm">Module-Level Inline Assembly</a>) through the use of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2820 a special value. This value represents the inline assembler as a string
2821 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2822 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2823 expression has side effects, and a flag indicating whether the function
2824 containing the asm needs to align its stack conservatively. An example
2825 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2826
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2827<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2828i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2829</pre>
2830
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2831<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2832 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2833 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2834
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2835<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2836%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]2837</pre>
2838
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2839<p>Inline asms with side effects not visible in the constraint list must be
2840 marked as having side effects. This is done through the use of the
2841 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2842
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2843<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2844call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2845</pre>
2846
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2847<p>In some cases inline asms will contain code that will not work unless the
2848 stack is aligned in some way, such as calls or SSE instructions on x86,
2849 yet will not contain code that does that alignment within the asm.
2850 The compiler should make conservative assumptions about what the asm might
2851 contain and should generate its usual stack alignment code in the prologue
2852 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2853
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2854<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2855call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2856</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2857
2858<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2859 first.</p>
2860
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame]2861<!--
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2862<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2863 documented here. Constraints on what can be done (e.g. duplication, moving,
2864 etc need to be documented). This is probably best done by reference to
2865 another document that covers inline asm from a holistic perspective.</p>
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame]2866 -->
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2867
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame]2868<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2869<h4>
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame]2870 <a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2871</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2872
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2873<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2874
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame]2875<p>The call instructions that wrap inline asm nodes may have a
2876 "<tt>!srcloc</tt>" MDNode attached to it that contains a list of constant
2877 integers. If present, the code generator will use the integer as the
2878 location cookie value when report errors through the <tt>LLVMContext</tt>
2879 error reporting mechanisms. This allows a front-end to correlate backend
2880 errors that occur with inline asm back to the source code that produced it.
2881 For example:</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2882
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2883<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2884call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2885...
2886!42 = !{ i32 1234567 }
2887</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2888
2889<p>It is up to the front-end to make sense of the magic numbers it places in the
Bill Wendlingaee0f452011-11-30 21:52:43 +0000[diff] [blame]2890 IR. If the MDNode contains multiple constants, the code generator will use
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2891 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]2892
2893</div>
2894
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2895</div>
2896
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2897<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2898<h3>
2899 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2900</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2901
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2902<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2903
2904<p>LLVM IR allows metadata to be attached to instructions in the program that
2905 can convey extra information about the code to the optimizers and code
2906 generator. One example application of metadata is source-level debug
2907 information. There are two metadata primitives: strings and nodes. All
2908 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2909 preceding exclamation point ('<tt>!</tt>').</p>
2910
2911<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2912 any character by escaping non-printable characters with "<tt>\xx</tt>" where
2913 "<tt>xx</tt>" is the two digit hex code. For example:
2914 "<tt>!"test\00"</tt>".</p>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2915
2916<p>Metadata nodes are represented with notation similar to structure constants
2917 (a comma separated list of elements, surrounded by braces and preceded by an
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2918 exclamation point). Metadata nodes can have any values as their operand. For
2919 example:</p>
2920
2921<div class="doc_code">
2922<pre>
2923!{ metadata !"test\00", i32 10}
2924</pre>
2925</div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2926
2927<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2928 metadata nodes, which can be looked up in the module symbol table. For
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2929 example:</p>
2930
2931<div class="doc_code">
2932<pre>
2933!foo = metadata !{!4, !3}
2934</pre>
2935</div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2936
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2937<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2938 function is using two metadata arguments:</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2939
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2940<div class="doc_code">
2941<pre>
2942call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2943</pre>
2944</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2945
2946<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2947 attached to the <tt>add</tt> instruction using the <tt>!dbg</tt>
2948 identifier:</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2949
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2950<div class="doc_code">
2951<pre>
2952%indvar.next = add i64 %indvar, 1, !dbg !21
2953</pre>
2954</div>
2955
Peter Collingbourne249d9532011-10-27 19:19:07 +0000[diff] [blame]2956<p>More information about specific metadata nodes recognized by the optimizers
2957 and code generator is found below.</p>
2958
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]2959<!-- _______________________________________________________________________ -->
Peter Collingbourne249d9532011-10-27 19:19:07 +0000[diff] [blame]2960<h4>
2961 <a name="tbaa">'<tt>tbaa</tt>' Metadata</a>
2962</h4>
2963
2964<div>
2965
2966<p>In LLVM IR, memory does not have types, so LLVM's own type system is not
2967 suitable for doing TBAA. Instead, metadata is added to the IR to describe
2968 a type system of a higher level language. This can be used to implement
2969 typical C/C++ TBAA, but it can also be used to implement custom alias
2970 analysis behavior for other languages.</p>
2971
2972<p>The current metadata format is very simple. TBAA metadata nodes have up to
2973 three fields, e.g.:</p>
2974
2975<div class="doc_code">
2976<pre>
2977!0 = metadata !{ metadata !"an example type tree" }
2978!1 = metadata !{ metadata !"int", metadata !0 }
2979!2 = metadata !{ metadata !"float", metadata !0 }
2980!3 = metadata !{ metadata !"const float", metadata !2, i64 1 }
2981</pre>
2982</div>
2983
2984<p>The first field is an identity field. It can be any value, usually
2985 a metadata string, which uniquely identifies the type. The most important
2986 name in the tree is the name of the root node. Two trees with
2987 different root node names are entirely disjoint, even if they
2988 have leaves with common names.</p>
2989
2990<p>The second field identifies the type's parent node in the tree, or
2991 is null or omitted for a root node. A type is considered to alias
2992 all of its descendants and all of its ancestors in the tree. Also,
2993 a type is considered to alias all types in other trees, so that
2994 bitcode produced from multiple front-ends is handled conservatively.</p>
2995
2996<p>If the third field is present, it's an integer which if equal to 1
2997 indicates that the type is "constant" (meaning
2998 <tt>pointsToConstantMemory</tt> should return true; see
2999 <a href="AliasAnalysis.html#OtherItfs">other useful
3000 <tt>AliasAnalysis</tt> methods</a>).</p>
3001
3002</div>
3003
Bill Wendlingf6cc4c22011-11-30 21:43:43 +0000[diff] [blame]3004<!-- _______________________________________________________________________ -->
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]3005<h4>
Duncan Sands5e5c5f82012-04-14 12:36:06 +0000[diff] [blame]3006 <a name="fpmath">'<tt>fpmath</tt>' Metadata</a>
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]3007</h4>
3008
3009<div>
3010
Duncan Sands5e5c5f82012-04-14 12:36:06 +0000[diff] [blame]3011<p><tt>fpmath</tt> metadata may be attached to any instruction of floating point
Duncan Sands8883c432012-04-16 16:28:59 +0000[diff] [blame]3012 type. It can be used to express the maximum acceptable error in the result of
3013 that instruction, in ULPs, thus potentially allowing the compiler to use a
Duncan Sands2867c852012-04-16 19:39:33 +0000[diff] [blame]3014 more efficient but less accurate method of computing it. ULP is defined as
3015 follows:</p>
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]3016
Bill Wendling0656e252011-11-09 19:33:56 +0000[diff] [blame]3017<blockquote>
3018
3019<p>If <tt>x</tt> is a real number that lies between two finite consecutive
3020 floating-point numbers <tt>a</tt> and <tt>b</tt>, without being equal to one
3021 of them, then <tt>ulp(x) = |b - a|</tt>, otherwise <tt>ulp(x)</tt> is the
3022 distance between the two non-equal finite floating-point numbers nearest
3023 <tt>x</tt>. Moreover, <tt>ulp(NaN)</tt> is <tt>NaN</tt>.</p>
3024
3025</blockquote>
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]3026
Duncan Sands8883c432012-04-16 16:28:59 +0000[diff] [blame]3027<p>The metadata node shall consist of a single positive floating point number
Duncan Sands2867c852012-04-16 19:39:33 +0000[diff] [blame]3028 representing the maximum relative error, for example:</p>
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]3029
3030<div class="doc_code">
3031<pre>
Duncan Sands8883c432012-04-16 16:28:59 +0000[diff] [blame]3032!0 = metadata !{ float 2.5 } ; maximum acceptable inaccuracy is 2.5 ULPs
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]3033</pre>
3034</div>
3035
NAKAMURA Takumi9c55f592012-03-27 11:25:16 +0000[diff] [blame]3036</div>
3037
Rafael Espindola39dd3282012-03-24 00:14:51 +0000[diff] [blame]3038<!-- _______________________________________________________________________ -->
3039<h4>
3040 <a name="range">'<tt>range</tt>' Metadata</a>
3041</h4>
3042
3043<div>
3044<p><tt>range</tt> metadata may be attached only to loads of integer types. It
3045 expresses the possible ranges the loaded value is in. The ranges are
3046 represented with a flattened list of integers. The loaded value is known to
3047 be in the union of the ranges defined by each consecutive pair. Each pair
3048 has the following properties:</p>
3049<ul>
3050 <li>The type must match the type loaded by the instruction.</li>
3051 <li>The pair <tt>a,b</tt> represents the range <tt>[a,b)</tt>.</li>
3052 <li>Both <tt>a</tt> and <tt>b</tt> are constants.</li>
3053 <li>The range is allowed to wrap.</li>
3054 <li>The range should not represent the full or empty set. That is,
3055 <tt>a!=b</tt>. </li>
3056</ul>
Rafael Espindolac49b29e2012-05-31 13:45:46 +0000[diff] [blame^]3057<p> In addiion, the pairs must be in signed order of the lower bound and
3058 they must be non contigous.</p>
Rafael Espindola39dd3282012-03-24 00:14:51 +0000[diff] [blame]3059
3060<p>Examples:</p>
3061<div class="doc_code">
3062<pre>
3063 %a = load i8* %x, align 1, !range !0 ; Can only be 0 or 1
3064 %b = load i8* %y, align 1, !range !1 ; Can only be 255 (-1), 0 or 1
3065 %c = load i8* %z, align 1, !range !2 ; Can only be 0, 1, 3, 4 or 5
Rafael Espindolac49b29e2012-05-31 13:45:46 +0000[diff] [blame^]3066 %d = load i8* %z, align 1, !range !3 ; Can only be -2, -1, 3, 4 or 5
Rafael Espindola39dd3282012-03-24 00:14:51 +0000[diff] [blame]3067...
3068!0 = metadata !{ i8 0, i8 2 }
3069!1 = metadata !{ i8 255, i8 2 }
3070!2 = metadata !{ i8 0, i8 2, i8 3, i8 6 }
Rafael Espindolac49b29e2012-05-31 13:45:46 +0000[diff] [blame^]3071!3 = metadata !{ i8 -2, i8 0, i8 3, i8 6 }
Rafael Espindola39dd3282012-03-24 00:14:51 +0000[diff] [blame]3072</pre>
3073</div>
3074</div>
Peter Collingbourne999f90b2011-10-27 19:19:14 +0000[diff] [blame]3075</div>
3076
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]3077</div>
3078
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3079<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3080<h2>
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]3081 <a name="module_flags">Module Flags Metadata</a>
3082</h2>
3083<!-- *********************************************************************** -->
3084
3085<div>
3086
3087<p>Information about the module as a whole is difficult to convey to LLVM's
3088 subsystems. The LLVM IR isn't sufficient to transmit this
3089 information. The <tt>llvm.module.flags</tt> named metadata exists in order to
3090 facilitate this. These flags are in the form of key / value pairs &mdash;
3091 much like a dictionary &mdash; making it easy for any subsystem who cares
3092 about a flag to look it up.</p>
3093
3094<p>The <tt>llvm.module.flags</tt> metadata contains a list of metadata
3095 triplets. Each triplet has the following form:</p>
3096
3097<ul>
3098 <li>The first element is a <i>behavior</i> flag, which specifies the behavior
3099 when two (or more) modules are merged together, and it encounters two (or
3100 more) metadata with the same ID. The supported behaviors are described
3101 below.</li>
3102
3103 <li>The second element is a metadata string that is a unique ID for the
3104 metadata. How each ID is interpreted is documented below.</li>
3105
3106 <li>The third element is the value of the flag.</li>
3107</ul>
3108
3109<p>When two (or more) modules are merged together, the resulting
3110 <tt>llvm.module.flags</tt> metadata is the union of the
3111 modules' <tt>llvm.module.flags</tt> metadata. The only exception being a flag
3112 with the <i>Override</i> behavior, which may override another flag's value
3113 (see below).</p>
3114
3115<p>The following behaviors are supported:</p>
3116
3117<table border="1" cellspacing="0" cellpadding="4">
3118 <tbody>
3119 <tr>
3120 <th>Value</th>
3121 <th>Behavior</th>
3122 </tr>
3123 <tr>
3124 <td>1</td>
3125 <td align="left">
Bill Wendlinga0edecf2012-03-06 09:17:04 +0000[diff] [blame]3126 <dl>
3127 <dt><b>Error</b></dt>
3128 <dd>Emits an error if two values disagree. It is an error to have an ID
3129 with both an Error and a Warning behavior.</dd>
3130 </dl>
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]3131 </td>
3132 </tr>
3133 <tr>
3134 <td>2</td>
3135 <td align="left">
Bill Wendlinga0edecf2012-03-06 09:17:04 +0000[diff] [blame]3136 <dl>
3137 <dt><b>Warning</b></dt>
3138 <dd>Emits a warning if two values disagree.</dd>
3139 </dl>
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]3140 </td>
3141 </tr>
3142 <tr>
3143 <td>3</td>
3144 <td align="left">
Bill Wendlinga0edecf2012-03-06 09:17:04 +0000[diff] [blame]3145 <dl>
3146 <dt><b>Require</b></dt>
3147 <dd>Emits an error when the specified value is not present or doesn't
3148 have the specified value. It is an error for two (or more)
3149 <tt>llvm.module.flags</tt> with the same ID to have the Require
3150 behavior but different values. There may be multiple Require flags
3151 per ID.</dd>
3152 </dl>
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]3153 </td>
3154 </tr>
3155 <tr>
3156 <td>4</td>
3157 <td align="left">
Bill Wendlinga0edecf2012-03-06 09:17:04 +0000[diff] [blame]3158 <dl>
3159 <dt><b>Override</b></dt>
3160 <dd>Uses the specified value if the two values disagree. It is an
3161 error for two (or more) <tt>llvm.module.flags</tt> with the same
3162 ID to have the Override behavior but different values.</dd>
3163 </dl>
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]3164 </td>
3165 </tr>
3166 </tbody>
3167</table>
3168
3169<p>An example of module flags:</p>
3170
3171<pre class="doc_code">
3172!0 = metadata !{ i32 1, metadata !"foo", i32 1 }
3173!1 = metadata !{ i32 4, metadata !"bar", i32 37 }
3174!2 = metadata !{ i32 2, metadata !"qux", i32 42 }
3175!3 = metadata !{ i32 3, metadata !"qux",
3176 metadata !{
3177 metadata !"foo", i32 1
3178 }
3179}
3180!llvm.module.flags = !{ !0, !1, !2, !3 }
3181</pre>
3182
3183<ul>
3184 <li><p>Metadata <tt>!0</tt> has the ID <tt>!"foo"</tt> and the value '1'. The
3185 behavior if two or more <tt>!"foo"</tt> flags are seen is to emit an
3186 error if their values are not equal.</p></li>
3187
3188 <li><p>Metadata <tt>!1</tt> has the ID <tt>!"bar"</tt> and the value '37'. The
3189 behavior if two or more <tt>!"bar"</tt> flags are seen is to use the
3190 value '37' if their values are not equal.</p></li>
3191
3192 <li><p>Metadata <tt>!2</tt> has the ID <tt>!"qux"</tt> and the value '42'. The
3193 behavior if two or more <tt>!"qux"</tt> flags are seen is to emit a
3194 warning if their values are not equal.</p></li>
3195
3196 <li><p>Metadata <tt>!3</tt> has the ID <tt>!"qux"</tt> and the value:</p>
3197
3198<pre class="doc_code">
3199metadata !{ metadata !"foo", i32 1 }
3200</pre>
Bill Wendlingf7b367c2012-02-16 01:10:50 +0000[diff] [blame]3201
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]3202 <p>The behavior is to emit an error if the <tt>llvm.module.flags</tt> does
3203 not contain a flag with the ID <tt>!"foo"</tt> that has the value
3204 '1'. If two or more <tt>!"qux"</tt> flags exist, then they must have
3205 the same value or an error will be issued.</p></li>
3206</ul>
3207
Bill Wendlingf7b367c2012-02-16 01:10:50 +0000[diff] [blame]3208
3209<!-- ======================================================================= -->
3210<h3>
3211<a name="objc_gc_flags">Objective-C Garbage Collection Module Flags Metadata</a>
3212</h3>
3213
3214<div>
3215
3216<p>On the Mach-O platform, Objective-C stores metadata about garbage collection
3217 in a special section called "image info". The metadata consists of a version
3218 number and a bitmask specifying what types of garbage collection are
3219 supported (if any) by the file. If two or more modules are linked together
3220 their garbage collection metadata needs to be merged rather than appended
3221 together.</p>
3222
3223<p>The Objective-C garbage collection module flags metadata consists of the
3224 following key-value pairs:</p>
3225
3226<table border="1" cellspacing="0" cellpadding="4">
Bill Wendlingb3ef2232012-03-06 09:23:25 +0000[diff] [blame]3227 <col width="30%">
Bill Wendlingf7b367c2012-02-16 01:10:50 +0000[diff] [blame]3228 <tbody>
3229 <tr>
Bill Wendlinga0edecf2012-03-06 09:17:04 +0000[diff] [blame]3230 <th>Key</th>
Bill Wendlingf7b367c2012-02-16 01:10:50 +0000[diff] [blame]3231 <th>Value</th>
3232 </tr>
3233 <tr>
3234 <td><tt>Objective-C&nbsp;Version</tt></td>
3235 <td align="left"><b>[Required]</b> &mdash; The Objective-C ABI
3236 version. Valid values are 1 and 2.</td>
3237 </tr>
3238 <tr>
3239 <td><tt>Objective-C&nbsp;Image&nbsp;Info&nbsp;Version</tt></td>
3240 <td align="left"><b>[Required]</b> &mdash; The version of the image info
3241 section. Currently always 0.</td>
3242 </tr>
3243 <tr>
3244 <td><tt>Objective-C&nbsp;Image&nbsp;Info&nbsp;Section</tt></td>
3245 <td align="left"><b>[Required]</b> &mdash; The section to place the
3246 metadata. Valid values are <tt>"__OBJC, __image_info, regular"</tt> for
3247 Objective-C ABI version 1, and <tt>"__DATA,__objc_imageinfo, regular,
3248 no_dead_strip"</tt> for Objective-C ABI version 2.</td>
3249 </tr>
3250 <tr>
3251 <td><tt>Objective-C&nbsp;Garbage&nbsp;Collection</tt></td>
3252 <td align="left"><b>[Required]</b> &mdash; Specifies whether garbage
3253 collection is supported or not. Valid values are 0, for no garbage
3254 collection, and 2, for garbage collection supported.</td>
3255 </tr>
3256 <tr>
3257 <td><tt>Objective-C&nbsp;GC&nbsp;Only</tt></td>
3258 <td align="left"><b>[Optional]</b> &mdash; Specifies that only garbage
3259 collection is supported. If present, its value must be 6. This flag
3260 requires that the <tt>Objective-C Garbage Collection</tt> flag have the
3261 value 2.</td>
3262 </tr>
3263 </tbody>
3264</table>
3265
3266<p>Some important flag interactions:</p>
3267
3268<ul>
3269 <li>If a module with <tt>Objective-C Garbage Collection</tt> set to 0 is
3270 merged with a module with <tt>Objective-C Garbage Collection</tt> set to
3271 2, then the resulting module has the <tt>Objective-C Garbage
3272 Collection</tt> flag set to 0.</li>
3273
3274 <li>A module with <tt>Objective-C Garbage Collection</tt> set to 0 cannot be
3275 merged with a module with <tt>Objective-C GC Only</tt> set to 6.</li>
3276</ul>
3277
3278</div>
3279
Bill Wendlingb9d75a92012-02-11 11:59:36 +0000[diff] [blame]3280</div>
3281
3282<!-- *********************************************************************** -->
3283<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3284 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3285</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3286<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3287<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3288<p>LLVM has a number of "magic" global variables that contain data that affect
3289code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3290of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
3291section and all globals that start with "<tt>llvm.</tt>" are reserved for use
3292by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3293
3294<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3295<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3296<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3297</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3298
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3299<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3300
3301<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
3302href="#linkage_appending">appending linkage</a>. This array contains a list of
3303pointers to global variables and functions which may optionally have a pointer
3304cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
3305
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3306<div class="doc_code">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3307<pre>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3308@X = global i8 4
3309@Y = global i32 123
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3310
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3311@llvm.used = appending global [2 x i8*] [
3312 i8* @X,
3313 i8* bitcast (i32* @Y to i8*)
3314], section "llvm.metadata"
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3315</pre>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3316</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3317
3318<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3319 compiler, assembler, and linker are required to treat the symbol as if there
3320 is a reference to the global that it cannot see. For example, if a variable
3321 has internal linkage and no references other than that from
3322 the <tt>@llvm.used</tt> list, it cannot be deleted. This is commonly used to
3323 represent references from inline asms and other things the compiler cannot
3324 "see", and corresponds to "<tt>attribute((used))</tt>" in GNU C.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3325
3326<p>On some targets, the code generator must emit a directive to the assembler or
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3327 object file to prevent the assembler and linker from molesting the
3328 symbol.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3329
3330</div>
3331
3332<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3333<h3>
3334 <a name="intg_compiler_used">
3335 The '<tt>llvm.compiler.used</tt>' Global Variable
3336 </a>
3337</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3338
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3339<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3340
3341<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3342 <tt>@llvm.used</tt> directive, except that it only prevents the compiler from
3343 touching the symbol. On targets that support it, this allows an intelligent
3344 linker to optimize references to the symbol without being impeded as it would
3345 be by <tt>@llvm.used</tt>.</p>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3346
3347<p>This is a rare construct that should only be used in rare circumstances, and
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3348 should not be exposed to source languages.</p>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]3349
3350</div>
3351
3352<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3353<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3354<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3355</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3356
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3357<div>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3358
3359<div class="doc_code">
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3360<pre>
3361%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]3362@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3363</pre>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3364</div>
3365
3366<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor
3367 functions and associated priorities. The functions referenced by this array
3368 will be called in ascending order of priority (i.e. lowest first) when the
3369 module is loaded. The order of functions with the same priority is not
3370 defined.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3371
3372</div>
3373
3374<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3375<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3376<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3377</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3378
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3379<div>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3380
3381<div class="doc_code">
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3382<pre>
3383%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]3384@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3385</pre>
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3386</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3387
Bill Wendling9ae75632011-11-08 00:32:45 +0000[diff] [blame]3388<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions
3389 and associated priorities. The functions referenced by this array will be
3390 called in descending order of priority (i.e. highest first) when the module
3391 is loaded. The order of functions with the same priority is not defined.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3392
3393</div>
3394
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3395</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3396
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]3397<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3398<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3399<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3400
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3401<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3402
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3403<p>The LLVM instruction set consists of several different classifications of
3404 instructions: <a href="#terminators">terminator
3405 instructions</a>, <a href="#binaryops">binary instructions</a>,
3406 <a href="#bitwiseops">bitwise binary instructions</a>,
3407 <a href="#memoryops">memory instructions</a>, and
3408 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3409
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3410<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3411<h3>
3412 <a name="terminators">Terminator Instructions</a>
3413</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3414
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3415<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3416
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3417<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3418 in a program ends with a "Terminator" instruction, which indicates which
3419 block should be executed after the current block is finished. These
3420 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3421 control flow, not values (the one exception being the
3422 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3423
Chris Lattner6445ecb2011-08-02 20:29:13 +0000[diff] [blame]3424<p>The terminator instructions are:
3425 '<a href="#i_ret"><tt>ret</tt></a>',
3426 '<a href="#i_br"><tt>br</tt></a>',
3427 '<a href="#i_switch"><tt>switch</tt></a>',
3428 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>',
3429 '<a href="#i_invoke"><tt>invoke</tt></a>',
Chris Lattner6445ecb2011-08-02 20:29:13 +0000[diff] [blame]3430 '<a href="#i_resume"><tt>resume</tt></a>', and
3431 '<a href="#i_unreachable"><tt>unreachable</tt></a>'.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3433<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3434<h4>
3435 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3436</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3437
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3438<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3439
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3440<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3441<pre>
3442 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]3443 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3444</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3445
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3446<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3447<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3448 a value) from a function back to the caller.</p>
3449
3450<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3451 value and then causes control flow, and one that just causes control flow to
3452 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3453
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3454<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3455<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3456 return value. The type of the return value must be a
3457 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3458
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3459<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3460 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3461 value or a return value with a type that does not match its type, or if it
3462 has a void return type and contains a '<tt>ret</tt>' instruction with a
3463 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3464
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3465<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3466<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3467 the calling function's context. If the caller is a
3468 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3469 instruction after the call. If the caller was an
3470 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3471 the beginning of the "normal" destination block. If the instruction returns
3472 a value, that value shall set the call or invoke instruction's return
3473 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3474
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3475<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3476<pre>
3477 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3478 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]3479 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]3480</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3481
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3482</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3483<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3484<h4>
3485 <a name="i_br">'<tt>br</tt>' Instruction</a>
3486</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3487
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3488<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3489
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3490<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3491<pre>
Bill Wendlingb3aa4712011-07-26 10:41:15 +0000[diff] [blame]3492 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3493 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3494</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3495
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3496<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3497<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3498 different basic block in the current function. There are two forms of this
3499 instruction, corresponding to a conditional branch and an unconditional
3500 branch.</p>
3501
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3502<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3503<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3504 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3505 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3506 target.</p>
3507
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3508<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3509<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3510 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3511 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3512 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3513
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3514<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3515<pre>
3516Test:
3517 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3518 br i1 %cond, label %IfEqual, label %IfUnequal
3519IfEqual:
3520 <a href="#i_ret">ret</a> i32 1
3521IfUnequal:
3522 <a href="#i_ret">ret</a> i32 0
3523</pre>
3524
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3525</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3526
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3527<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3528<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3529 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3530</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3531
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3532<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3533
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3534<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3535<pre>
3536 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3537</pre>
3538
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3539<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3540<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]3541 several different places. It is a generalization of the '<tt>br</tt>'
3542 instruction, allowing a branch to occur to one of many possible
3543 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3544
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3545<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3546<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3547 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3548 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3549 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3550
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3551<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3552<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3553 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3554 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3555 transferred to the corresponding destination; otherwise, control flow is
3556 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3557
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3558<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3559<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3560 <tt>switch</tt> instruction, this instruction may be code generated in
3561 different ways. For example, it could be generated as a series of chained
3562 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3563
3564<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3565<pre>
3566 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3567 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3568 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3569
3570 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3571 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3572
3573 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3574 switch i32 %val, label %otherwise [ i32 0, label %onzero
3575 i32 1, label %onone
3576 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3577</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3578
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3579</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3580
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3581
3582<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3583<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3584 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3585</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3586
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3587<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3588
3589<h5>Syntax:</h5>
3590<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3591 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]3592</pre>
3593
3594<h5>Overview:</h5>
3595
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3596<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3597 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3598 "<tt>address</tt>". Address must be derived from a <a
3599 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3600
3601<h5>Arguments:</h5>
3602
3603<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3604 rest of the arguments indicate the full set of possible destinations that the
3605 address may point to. Blocks are allowed to occur multiple times in the
3606 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3607
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3608<p>This destination list is required so that dataflow analysis has an accurate
3609 understanding of the CFG.</p>
3610
3611<h5>Semantics:</h5>
3612
3613<p>Control transfers to the block specified in the address argument. All
3614 possible destination blocks must be listed in the label list, otherwise this
3615 instruction has undefined behavior. This implies that jumps to labels
3616 defined in other functions have undefined behavior as well.</p>
3617
3618<h5>Implementation:</h5>
3619
3620<p>This is typically implemented with a jump through a register.</p>
3621
3622<h5>Example:</h5>
3623<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3624 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3625</pre>
3626
3627</div>
3628
3629
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3630<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3631<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3632 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3633</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3634
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3635<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3636
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3637<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3638<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3639 &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]3640 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3641</pre>
3642
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3643<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3644<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3645 function, with the possibility of control flow transfer to either the
3646 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3647 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3648 control flow will return to the "normal" label. If the callee (or any
Bill Wendling7b9e5392012-02-06 21:57:33 +0000[diff] [blame]3649 indirect callees) returns via the "<a href="#i_resume"><tt>resume</tt></a>"
3650 instruction or other exception handling mechanism, control is interrupted and
3651 continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3652
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3653<p>The '<tt>exception</tt>' label is a
3654 <i><a href="ExceptionHandling.html#overview">landing pad</a></i> for the
3655 exception. As such, '<tt>exception</tt>' label is required to have the
3656 "<a href="#i_landingpad"><tt>landingpad</tt></a>" instruction, which contains
Chad Rosier85f5a1a2011-12-09 02:00:44 +0000[diff] [blame]3657 the information about the behavior of the program after unwinding
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3658 happens, as its first non-PHI instruction. The restrictions on the
3659 "<tt>landingpad</tt>" instruction's tightly couples it to the
3660 "<tt>invoke</tt>" instruction, so that the important information contained
3661 within the "<tt>landingpad</tt>" instruction can't be lost through normal
3662 code motion.</p>
3663
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3664<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3665<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3666
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3667<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3668 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3669 convention</a> the call should use. If none is specified, the call
3670 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3671
3672 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3673 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3674 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3675
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3676 <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]3677 function value being invoked. In most cases, this is a direct function
3678 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3679 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3680
3681 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3682 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3683
3684 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3685 signature argument types and parameter attributes. All arguments must be
3686 of <a href="#t_firstclass">first class</a> type. If the function
3687 signature indicates the function accepts a variable number of arguments,
3688 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3689
3690 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3691 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3692
Bill Wendling7b9e5392012-02-06 21:57:33 +0000[diff] [blame]3693 <li>'<tt>exception label</tt>': the label reached when a callee returns via
3694 the <a href="#i_resume"><tt>resume</tt></a> instruction or other exception
3695 handling mechanism.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3696
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3697 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3698 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3699 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3700</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3701
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3702<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3703<p>This instruction is designed to operate as a standard
3704 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3705 primary difference is that it establishes an association with a label, which
3706 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3707
3708<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3709 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3710 exception. Additionally, this is important for implementation of
3711 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3712
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3713<p>For the purposes of the SSA form, the definition of the value returned by the
3714 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3715 block to the "normal" label. If the callee unwinds then no return value is
3716 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3717
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3718<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3719<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3720 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3721 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3722 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3723 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3724</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3725
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3726</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3727
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3728 <!-- _______________________________________________________________________ -->
3729
3730<h4>
3731 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3732</h4>
3733
3734<div>
3735
3736<h5>Syntax:</h5>
3737<pre>
3738 resume &lt;type&gt; &lt;value&gt;
3739</pre>
3740
3741<h5>Overview:</h5>
3742<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3743 successors.</p>
3744
3745<h5>Arguments:</h5>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3746<p>The '<tt>resume</tt>' instruction requires one argument, which must have the
Bill Wendlinge4ad50b2011-08-03 18:37:32 +0000[diff] [blame]3747 same type as the result of any '<tt>landingpad</tt>' instruction in the same
3748 function.</p>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3749
3750<h5>Semantics:</h5>
3751<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3752 (in-flight) exception whose unwinding was interrupted with
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3753 a <a href="#i_landingpad"><tt>landingpad</tt></a> instruction.</p>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3754
3755<h5>Example:</h5>
3756<pre>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3757 resume { i8*, i32 } %exn
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3758</pre>
3759
3760</div>
3761
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3762<!-- _______________________________________________________________________ -->
3763
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3764<h4>
3765 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3766</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3767
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3768<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3769
3770<h5>Syntax:</h5>
3771<pre>
3772 unreachable
3773</pre>
3774
3775<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3776<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3777 instruction is used to inform the optimizer that a particular portion of the
3778 code is not reachable. This can be used to indicate that the code after a
3779 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3780
3781<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3782<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3783
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3784</div>
3785
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3786</div>
3787
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3788<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3789<h3>
3790 <a name="binaryops">Binary Operations</a>
3791</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3792
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3793<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3794
3795<p>Binary operators are used to do most of the computation in a program. They
3796 require two operands of the same type, execute an operation on them, and
3797 produce a single value. The operands might represent multiple data, as is
3798 the case with the <a href="#t_vector">vector</a> data type. The result value
3799 has the same type as its operands.</p>
3800
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3801<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3802
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3803<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3804<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3805 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3806</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3807
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3808<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3809
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3810<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3811<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3812 &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]3813 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3814 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3815 &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]3816</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3817
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3818<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3819<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3820
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3821<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3822<p>The two arguments to the '<tt>add</tt>' instruction must
3823 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3824 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3825
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3826<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3827<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3828
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3829<p>If the sum has unsigned overflow, the result returned is the mathematical
3830 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]3831
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3832<p>Because LLVM integers use a two's complement representation, this instruction
3833 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3834
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3835<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3836 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3837 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]3838 is a <a href="#poisonvalues">poison value</a> if unsigned and/or signed overflow,
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3839 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3840
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3841<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3842<pre>
3843 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3844</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3845
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3846</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3847
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3848<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3849<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3850 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3851</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3852
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3853<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3854
3855<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3856<pre>
3857 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3858</pre>
3859
3860<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3861<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3862
3863<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3864<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3865 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3866 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3867
3868<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3869<p>The value produced is the floating point sum of the two operands.</p>
3870
3871<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3872<pre>
3873 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3874</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3875
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3876</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3877
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3878<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3879<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3880 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3881</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3882
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3883<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3884
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3885<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3886<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3887 &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]3888 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3889 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3890 &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]3891</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3892
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3893<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3894<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3895 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3896
3897<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3898 '<tt>neg</tt>' instruction present in most other intermediate
3899 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3900
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3901<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3902<p>The two arguments to the '<tt>sub</tt>' instruction must
3903 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3904 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3905
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3906<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3907<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3908
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3909<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3910 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3911 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3912
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3913<p>Because LLVM integers use a two's complement representation, this instruction
3914 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3915
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3916<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3917 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3918 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]3919 is a <a href="#poisonvalues">poison value</a> if unsigned and/or signed overflow,
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3920 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3921
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3922<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3923<pre>
3924 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3925 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3926</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3927
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3928</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3929
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3930<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3931<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3932 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3933</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3934
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3935<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3936
3937<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3938<pre>
3939 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3940</pre>
3941
3942<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3943<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3944 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3945
3946<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3947 '<tt>fneg</tt>' instruction present in most other intermediate
3948 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3949
3950<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3951<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3952 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3953 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3954
3955<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3956<p>The value produced is the floating point difference of the two operands.</p>
3957
3958<h5>Example:</h5>
3959<pre>
3960 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3961 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3962</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3963
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3964</div>
3965
3966<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3967<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3968 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3969</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3970
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3971<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3972
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3973<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3974<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3975 &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]3976 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3977 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3978 &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]3979</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3980
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3981<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3982<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3983
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3984<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3985<p>The two arguments to the '<tt>mul</tt>' instruction must
3986 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3987 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3988
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3989<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3990<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3991
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3992<p>If the result of the multiplication has unsigned overflow, the result
3993 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3994 width of the result.</p>
3995
3996<p>Because LLVM integers use a two's complement representation, and the result
3997 is the same width as the operands, this instruction returns the correct
3998 result for both signed and unsigned integers. If a full product
3999 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
4000 be sign-extended or zero-extended as appropriate to the width of the full
4001 product.</p>
4002
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]4003<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
4004 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
4005 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]4006 is a <a href="#poisonvalues">poison value</a> if unsigned and/or signed overflow,
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]4007 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]4008
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4009<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4010<pre>
4011 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4012</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4013
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4014</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4015
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4016<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4017<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4018 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4019</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4020
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4021<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4022
4023<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4024<pre>
4025 &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]4026</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4027
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4028<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4029<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4030
4031<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4032<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4033 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
4034 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4035
4036<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4037<p>The value produced is the floating point product of the two operands.</p>
4038
4039<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4040<pre>
4041 &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]4042</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4043
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]4044</div>
4045
4046<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4047<h4>
4048 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
4049</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4050
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4051<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4052
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4053<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4054<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]4055 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4056 &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]4057</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4058
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4059<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4060<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4061
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4062<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4063<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4064 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4065 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4066
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4067<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4068<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4069
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4070<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4071 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
4072
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4073<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4074
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]4075<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]4076 <tt>udiv</tt> is a <a href="#poisonvalues">poison value</a> if %op1 is not a
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]4077 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
4078
4079
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4080<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4081<pre>
4082 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4083</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4084
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4085</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4086
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4087<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4088<h4>
4089 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
4090</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4091
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4092<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4093
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4094<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4095<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]4096 &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]4097 &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]4098</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4099
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4100<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4101<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4102
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4103<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4104<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4105 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4106 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4107
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4108<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4109<p>The value produced is the signed integer quotient of the two operands rounded
4110 towards zero.</p>
4111
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4112<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4113 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
4114
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4115<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4116 undefined behavior; this is a rare case, but can occur, for example, by doing
4117 a 32-bit division of -2147483648 by -1.</p>
4118
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]4119<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]4120 <tt>sdiv</tt> is a <a href="#poisonvalues">poison value</a> if the result would
Dan Gohman38da9272010-07-11 00:08:34 +0000[diff] [blame]4121 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]4122
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4123<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4124<pre>
4125 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4126</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4127
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4128</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4129
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4130<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4131<h4>
4132 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
4133</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4134
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4135<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4136
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4137<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4138<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4139 &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]4140</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4141
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4142<h5>Overview:</h5>
4143<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4144
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4145<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4146<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4147 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
4148 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4149
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4150<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]4151<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4152
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4153<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4154<pre>
4155 &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]4156</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4157
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4158</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4159
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4160<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4161<h4>
4162 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
4163</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4164
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4165<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4166
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4167<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4168<pre>
4169 &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]4170</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4171
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4172<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4173<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
4174 division of its two arguments.</p>
4175
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4176<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4177<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4178 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4179 values. Both arguments must have identical types.</p>
4180
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4181<h5>Semantics:</h5>
4182<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4183 This instruction always performs an unsigned division to get the
4184 remainder.</p>
4185
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4186<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4187 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
4188
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4189<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4190
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4191<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4192<pre>
4193 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4194</pre>
4195
4196</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4197
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4198<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4199<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4200 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4201</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4202
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4203<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4204
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4205<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4206<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4207 &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]4208</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4209
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4210<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4211<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
4212 division of its two operands. This instruction can also take
4213 <a href="#t_vector">vector</a> versions of the values in which case the
4214 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]4215
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4216<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4217<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4218 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4219 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4220
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4221<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4222<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]4223 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
4224 <i>modulo</i> operator (where the result is either zero or has the same sign
4225 as the divisor, <tt>op2</tt>) of a value.
4226 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4227 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
4228 Math Forum</a>. For a table of how this is implemented in various languages,
4229 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
4230 Wikipedia: modulo operation</a>.</p>
4231
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4232<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4233 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
4234
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]4235<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4236 Overflow also leads to undefined behavior; this is a rare case, but can
4237 occur, for example, by taking the remainder of a 32-bit division of
4238 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
4239 lets srem be implemented using instructions that return both the result of
4240 the division and the remainder.)</p>
4241
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4242<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4243<pre>
4244 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4245</pre>
4246
4247</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4248
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4249<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4250<h4>
4251 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
4252</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4253
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4254<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4255
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4256<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4257<pre>
4258 &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]4259</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4260
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4261<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4262<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
4263 its two operands.</p>
4264
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4265<h5>Arguments:</h5>
4266<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4267 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
4268 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4269
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4270<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4271<p>This instruction returns the <i>remainder</i> of a division. The remainder
4272 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4273
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]4274<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4275<pre>
4276 &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]4277</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4278
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4279</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]4280
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4281</div>
4282
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]4283<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4284<h3>
4285 <a name="bitwiseops">Bitwise Binary Operations</a>
4286</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4287
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4288<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4289
4290<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
4291 program. They are generally very efficient instructions and can commonly be
4292 strength reduced from other instructions. They require two operands of the
4293 same type, execute an operation on them, and produce a single value. The
4294 resulting value is the same type as its operands.</p>
4295
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4296<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4297<h4>
4298 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
4299</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4300
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4301<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4302
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4303<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4304<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4305 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4306 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4307 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4308 &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]4309</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4310
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4311<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4312<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
4313 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4314
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4315<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4316<p>Both arguments to the '<tt>shl</tt>' instruction must be the
4317 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
4318 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4319
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4320<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4321<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
4322 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
4323 is (statically or dynamically) negative or equal to or larger than the number
4324 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4325 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4326 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4327
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4328<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]4329 <a href="#poisonvalues">poison value</a> if it shifts out any non-zero bits. If
Chris Lattner66298c12011-02-09 16:44:44 +0000[diff] [blame]4330 the <tt>nsw</tt> keyword is present, then the shift produces a
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]4331 <a href="#poisonvalues">poison value</a> if it shifts out any bits that disagree
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4332 with the resultant sign bit. As such, NUW/NSW have the same semantics as
4333 they would if the shift were expressed as a mul instruction with the same
4334 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
4335
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4336<h5>Example:</h5>
4337<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4338 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
4339 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
4340 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4341 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4342 &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]4343</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4344
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4345</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4346
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4347<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4348<h4>
4349 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
4350</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4351
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4352<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4353
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4354<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4355<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4356 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4357 &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]4358</pre>
4359
4360<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4361<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
4362 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4363
4364<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4365<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4366 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4367 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4368
4369<h5>Semantics:</h5>
4370<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4371 significant bits of the result will be filled with zero bits after the shift.
4372 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
4373 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4374 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4375 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4376
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4377<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]4378 <tt>lshr</tt> is a <a href="#poisonvalues">poison value</a> if any of the bits
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4379 shifted out are non-zero.</p>
4380
4381
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4382<h5>Example:</h5>
4383<pre>
4384 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4385 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4386 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4387 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4388 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4389 &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]4390</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4391
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4392</div>
4393
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]4394<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4395<h4>
4396 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4397</h4>
4398
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4399<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4400
4401<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4402<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4403 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4404 &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]4405</pre>
4406
4407<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4408<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4409 operand shifted to the right a specified number of bits with sign
4410 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4411
4412<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4413<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4414 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4415 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4416
4417<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4418<p>This instruction always performs an arithmetic shift right operation, The
4419 most significant bits of the result will be filled with the sign bit
4420 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4421 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4422 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4423 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4424
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4425<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]4426 <tt>ashr</tt> is a <a href="#poisonvalues">poison value</a> if any of the bits
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4427 shifted out are non-zero.</p>
4428
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4429<h5>Example:</h5>
4430<pre>
4431 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4432 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4433 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4434 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4435 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4436 &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]4437</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4438
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4439</div>
4440
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4441<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4442<h4>
4443 <a name="i_and">'<tt>and</tt>' Instruction</a>
4444</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4445
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4446<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4447
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4448<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4449<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4450 &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]4451</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4452
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4453<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4454<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4455 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4456
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4457<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4458<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4459 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4460 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4461
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4462<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4463<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4464
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4465<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4466 <tbody>
4467 <tr>
Bill Wendling262396b2011-12-09 22:41:40 +0000[diff] [blame]4468 <th>In0</th>
4469 <th>In1</th>
4470 <th>Out</th>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4471 </tr>
4472 <tr>
4473 <td>0</td>
4474 <td>0</td>
4475 <td>0</td>
4476 </tr>
4477 <tr>
4478 <td>0</td>
4479 <td>1</td>
4480 <td>0</td>
4481 </tr>
4482 <tr>
4483 <td>1</td>
4484 <td>0</td>
4485 <td>0</td>
4486 </tr>
4487 <tr>
4488 <td>1</td>
4489 <td>1</td>
4490 <td>1</td>
4491 </tr>
4492 </tbody>
4493</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4494
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4495<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4496<pre>
4497 &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]4498 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4499 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4500</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4501</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4502<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4503<h4>
4504 <a name="i_or">'<tt>or</tt>' Instruction</a>
4505</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4506
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4507<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4508
4509<h5>Syntax:</h5>
4510<pre>
4511 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4512</pre>
4513
4514<h5>Overview:</h5>
4515<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4516 two operands.</p>
4517
4518<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4519<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4520 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4521 values. Both arguments must have identical types.</p>
4522
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4523<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4524<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4525
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4526<table border="1" cellspacing="0" cellpadding="4">
4527 <tbody>
4528 <tr>
Bill Wendling262396b2011-12-09 22:41:40 +0000[diff] [blame]4529 <th>In0</th>
4530 <th>In1</th>
4531 <th>Out</th>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4532 </tr>
4533 <tr>
4534 <td>0</td>
4535 <td>0</td>
4536 <td>0</td>
4537 </tr>
4538 <tr>
4539 <td>0</td>
4540 <td>1</td>
4541 <td>1</td>
4542 </tr>
4543 <tr>
4544 <td>1</td>
4545 <td>0</td>
4546 <td>1</td>
4547 </tr>
4548 <tr>
4549 <td>1</td>
4550 <td>1</td>
4551 <td>1</td>
4552 </tr>
4553 </tbody>
4554</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4555
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4556<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4557<pre>
4558 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4559 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4560 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4561</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4562
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4563</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4564
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4565<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4566<h4>
4567 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4568</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4569
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4570<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4571
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4572<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4573<pre>
4574 &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]4575</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4576
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4577<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4578<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4579 its two operands. The <tt>xor</tt> is used to implement the "one's
4580 complement" operation, which is the "~" operator in C.</p>
4581
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4582<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4583<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4584 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4585 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4586
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4587<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4588<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4589
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4590<table border="1" cellspacing="0" cellpadding="4">
4591 <tbody>
4592 <tr>
Bill Wendling262396b2011-12-09 22:41:40 +0000[diff] [blame]4593 <th>In0</th>
4594 <th>In1</th>
4595 <th>Out</th>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4596 </tr>
4597 <tr>
4598 <td>0</td>
4599 <td>0</td>
4600 <td>0</td>
4601 </tr>
4602 <tr>
4603 <td>0</td>
4604 <td>1</td>
4605 <td>1</td>
4606 </tr>
4607 <tr>
4608 <td>1</td>
4609 <td>0</td>
4610 <td>1</td>
4611 </tr>
4612 <tr>
4613 <td>1</td>
4614 <td>1</td>
4615 <td>0</td>
4616 </tr>
4617 </tbody>
4618</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4619
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4620<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4621<pre>
4622 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4623 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4624 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4625 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4626</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4627
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4628</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4629
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4630</div>
4631
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4632<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4633<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4634 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4635</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4636
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4637<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4638
4639<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4640 target-independent manner. These instructions cover the element-access and
4641 vector-specific operations needed to process vectors effectively. While LLVM
4642 does directly support these vector operations, many sophisticated algorithms
4643 will want to use target-specific intrinsics to take full advantage of a
4644 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4645
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4646<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4647<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4648 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4649</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4650
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4651<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4652
4653<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4654<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4655 &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]4656</pre>
4657
4658<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4659<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4660 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4661
4662
4663<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4664<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4665 of <a href="#t_vector">vector</a> type. The second operand is an index
4666 indicating the position from which to extract the element. The index may be
4667 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4668
4669<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4670<p>The result is a scalar of the same type as the element type of
4671 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4672 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4673 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4674
4675<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4676<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4677 &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]4678</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4679
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4680</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4681
4682<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4683<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4684 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4685</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4686
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4687<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4688
4689<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4690<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4691 &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]4692</pre>
4693
4694<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4695<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4696 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4697
4698<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4699<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4700 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4701 whose type must equal the element type of the first operand. The third
4702 operand is an index indicating the position at which to insert the value.
4703 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4704
4705<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4706<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4707 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4708 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4709 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4710
4711<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4712<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4713 &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]4714</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4715
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4716</div>
4717
4718<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4719<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4720 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4721</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4722
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4723<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4724
4725<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4726<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4727 &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]4728</pre>
4729
4730<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4731<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4732 from two input vectors, returning a vector with the same element type as the
4733 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4734
4735<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4736<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4737 with types that match each other. The third argument is a shuffle mask whose
4738 element type is always 'i32'. The result of the instruction is a vector
4739 whose length is the same as the shuffle mask and whose element type is the
4740 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4741
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4742<p>The shuffle mask operand is required to be a constant vector with either
4743 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4744
4745<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4746<p>The elements of the two input vectors are numbered from left to right across
4747 both of the vectors. The shuffle mask operand specifies, for each element of
4748 the result vector, which element of the two input vectors the result element
4749 gets. The element selector may be undef (meaning "don't care") and the
4750 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4751
4752<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4753<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4754 &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]4755 &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]4756 &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]4757 &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]4758 &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]4759 &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]4760 &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]4761 &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]4762</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4763
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4764</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4765
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4766</div>
4767
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4768<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4769<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4770 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4771</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4772
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4773<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4774
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4775<p>LLVM supports several instructions for working with
4776 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4777
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4778<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4779<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4780 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4781</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4782
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4783<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4784
4785<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4786<pre>
4787 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4788</pre>
4789
4790<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4791<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4792 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4793
4794<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4795<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4796 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4797 <a href="#t_array">array</a> type. The operands are constant indices to
4798 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4799 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4800 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4801 <ul>
4802 <li>Since the value being indexed is not a pointer, the first index is
4803 omitted and assumed to be zero.</li>
4804 <li>At least one index must be specified.</li>
4805 <li>Not only struct indices but also array indices must be in
4806 bounds.</li>
4807 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4808
4809<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4810<p>The result is the value at the position in the aggregate specified by the
4811 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4812
4813<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4814<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4815 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4816</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4817
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4818</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4819
4820<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4821<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4822 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4823</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4824
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4825<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4826
4827<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4828<pre>
Bill Wendling194229e2011-07-26 20:42:28 +0000[diff] [blame]4829 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, &lt;idx&gt;}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4830</pre>
4831
4832<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4833<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4834 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4835
4836<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4837<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4838 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4839 <a href="#t_array">array</a> type. The second operand is a first-class
4840 value to insert. The following operands are constant indices indicating
4841 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]4842 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4843 value to insert must have the same type as the value identified by the
4844 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4845
4846<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4847<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4848 that of <tt>val</tt> except that the value at the position specified by the
4849 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4850
4851<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4852<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4853 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4854 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4855 %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]4856</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4857
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4858</div>
4859
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4860</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4861
4862<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4863<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4864 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4865</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4866
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4867<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4868
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4869<p>A key design point of an SSA-based representation is how it represents
4870 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4871 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4872 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4873
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4874<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4875<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4876 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4877</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4878
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4879<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4880
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4881<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4882<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4883 &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]4884</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4885
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4886<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4887<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4888 currently executing function, to be automatically released when this function
4889 returns to its caller. The object is always allocated in the generic address
4890 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4891
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4892<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4893<p>The '<tt>alloca</tt>' instruction
4894 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4895 runtime stack, returning a pointer of the appropriate type to the program.
4896 If "NumElements" is specified, it is the number of elements allocated,
4897 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4898 specified, the value result of the allocation is guaranteed to be aligned to
4899 at least that boundary. If not specified, or if zero, the target can choose
4900 to align the allocation on any convenient boundary compatible with the
4901 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4902
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4903<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4904
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4905<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4906<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4907 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4908 memory is automatically released when the function returns. The
4909 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4910 variables that must have an address available. When the function returns
4911 (either with the <tt><a href="#i_ret">ret</a></tt>
Bill Wendling7b9e5392012-02-06 21:57:33 +0000[diff] [blame]4912 or <tt><a href="#i_resume">resume</a></tt> instructions), the memory is
Nick Lewycky84a1d232012-02-29 08:26:44 +0000[diff] [blame]4913 reclaimed. Allocating zero bytes is legal, but the result is undefined.
4914 The order in which memory is allocated (ie., which way the stack grows) is
Nick Lewycky75d05e62012-03-18 09:35:50 +0000[diff] [blame]4915 not specified.</p>
Nick Lewycky84a1d232012-02-29 08:26:44 +0000[diff] [blame]4916
4917<p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4918
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4919<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4920<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4921 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4922 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4923 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4924 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4925</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4926
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4927</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4928
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4929<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4930<h4>
4931 <a name="i_load">'<tt>load</tt>' Instruction</a>
4932</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4933
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4934<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4935
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4936<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4937<pre>
Pete Cooperf95acc62012-02-10 18:13:54 +0000[diff] [blame]4938 &lt;result&gt; = load [volatile] &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;][, !invariant.load !&lt;index&gt;]
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4939 &lt;result&gt; = load atomic [volatile] &lt;ty&gt;* &lt;pointer&gt; [singlethread] &lt;ordering&gt;, align &lt;alignment&gt;
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4940 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4941</pre>
4942
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4943<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4944<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4945
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4946<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4947<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4948 from which to load. The pointer must point to
4949 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4950 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4951 number or order of execution of this <tt>load</tt> with other <a
4952 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4953
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4954<p>If the <code>load</code> is marked as <code>atomic</code>, it takes an extra
4955 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
4956 argument. The <code>release</code> and <code>acq_rel</code> orderings are
4957 not valid on <code>load</code> instructions. Atomic loads produce <a
4958 href="#memorymodel">defined</a> results when they may see multiple atomic
4959 stores. The type of the pointee must be an integer type whose bit width
4960 is a power of two greater than or equal to eight and less than or equal
4961 to a target-specific size limit. <code>align</code> must be explicitly
4962 specified on atomic loads, and the load has undefined behavior if the
4963 alignment is not set to a value which is at least the size in bytes of
4964 the pointee. <code>!nontemporal</code> does not have any defined semantics
4965 for atomic loads.</p>
4966
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4967<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4968 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]4969 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4970 alignment for the target. It is the responsibility of the code emitter to
4971 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4972 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4973 produce less efficient code. An alignment of 1 is always safe.</p>
4974
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4975<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4976 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4977 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4978 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4979 and code generator that this load is not expected to be reused in the cache.
4980 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4981 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4982
Pete Cooperf95acc62012-02-10 18:13:54 +0000[diff] [blame]4983<p>The optional <tt>!invariant.load</tt> metadata must reference a single
4984 metatadata name &lt;index&gt; corresponding to a metadata node with no
4985 entries. The existence of the <tt>!invariant.load</tt> metatadata on the
4986 instruction tells the optimizer and code generator that this load address
4987 points to memory which does not change value during program execution.
4988 The optimizer may then move this load around, for example, by hoisting it
4989 out of loops using loop invariant code motion.</p>
4990
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4991<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4992<p>The location of memory pointed to is loaded. If the value being loaded is of
4993 scalar type then the number of bytes read does not exceed the minimum number
4994 of bytes needed to hold all bits of the type. For example, loading an
4995 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4996 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4997 is undefined if the value was not originally written using a store of the
4998 same type.</p>
4999
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5000<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5001<pre>
5002 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
5003 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5004 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5005</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5006
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5007</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5008
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5009<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5010<h4>
5011 <a name="i_store">'<tt>store</tt>' Instruction</a>
5012</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5013
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5014<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5015
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5016<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5017<pre>
Bill Wendling262396b2011-12-09 22:41:40 +0000[diff] [blame]5018 store [volatile] &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
5019 store atomic [volatile] &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt; [singlethread] &lt;ordering&gt;, align &lt;alignment&gt; <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5020</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5021
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5022<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5023<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5024
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5025<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5026<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
5027 and an address at which to store it. The type of the
5028 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
5029 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]5030 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
5031 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
5032 order of execution of this <tt>store</tt> with other <a
5033 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5034
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]5035<p>If the <code>store</code> is marked as <code>atomic</code>, it takes an extra
5036 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
5037 argument. The <code>acquire</code> and <code>acq_rel</code> orderings aren't
5038 valid on <code>store</code> instructions. Atomic loads produce <a
5039 href="#memorymodel">defined</a> results when they may see multiple atomic
5040 stores. The type of the pointee must be an integer type whose bit width
5041 is a power of two greater than or equal to eight and less than or equal
5042 to a target-specific size limit. <code>align</code> must be explicitly
5043 specified on atomic stores, and the store has undefined behavior if the
5044 alignment is not set to a value which is at least the size in bytes of
5045 the pointee. <code>!nontemporal</code> does not have any defined semantics
5046 for atomic stores.</p>
5047
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5048<p>The optional constant "align" argument specifies the alignment of the
5049 operation (that is, the alignment of the memory address). A value of 0 or an
5050 omitted "align" argument means that the operation has the preferential
5051 alignment for the target. It is the responsibility of the code emitter to
5052 ensure that the alignment information is correct. Overestimating the
5053 alignment results in an undefined behavior. Underestimating the alignment may
5054 produce less efficient code. An alignment of 1 is always safe.</p>
5055
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]5056<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5057 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5058 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]5059 instruction tells the optimizer and code generator that this load is
5060 not expected to be reused in the cache. The code generator may
5061 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5062 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]5063
5064
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5065<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5066<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
5067 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
5068 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
5069 does not exceed the minimum number of bytes needed to hold all bits of the
5070 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
5071 writing a value of a type like <tt>i20</tt> with a size that is not an
5072 integral number of bytes, it is unspecified what happens to the extra bits
5073 that do not belong to the type, but they will typically be overwritten.</p>
5074
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5075<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5076<pre>
5077 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]5078 store i32 3, i32* %ptr <i>; yields {void}</i>
5079 %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]5080</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5081
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]5082</div>
5083
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]5084<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]5085<h4>
5086<a name="i_fence">'<tt>fence</tt>' Instruction</a>
5087</h4>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]5088
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]5089<div>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]5090
5091<h5>Syntax:</h5>
5092<pre>
5093 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
5094</pre>
5095
5096<h5>Overview:</h5>
5097<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
5098between operations.</p>
5099
5100<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
5101href="#ordering">ordering</a> argument which defines what
5102<i>synchronizes-with</i> edges they add. They can only be given
5103<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
5104<code>seq_cst</code> orderings.</p>
5105
5106<h5>Semantics:</h5>
5107<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
5108semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
5109<code>acquire</code> ordering semantics if and only if there exist atomic
5110operations <var>X</var> and <var>Y</var>, both operating on some atomic object
5111<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
5112<var>X</var> modifies <var>M</var> (either directly or through some side effect
5113of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
5114<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
5115<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
5116than an explicit <code>fence</code>, one (but not both) of the atomic operations
5117<var>X</var> or <var>Y</var> might provide a <code>release</code> or
5118<code>acquire</code> (resp.) ordering constraint and still
5119<i>synchronize-with</i> the explicit <code>fence</code> and establish the
5120<i>happens-before</i> edge.</p>
5121
5122<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
5123having both <code>acquire</code> and <code>release</code> semantics specified
5124above, participates in the global program order of other <code>seq_cst</code>
5125operations and/or fences.</p>
5126
5127<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
5128specifies that the fence only synchronizes with other fences in the same
5129thread. (This is useful for interacting with signal handlers.)</p>
5130
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]5131<h5>Example:</h5>
5132<pre>
5133 fence acquire <i>; yields {void}</i>
5134 fence singlethread seq_cst <i>; yields {void}</i>
5135</pre>
5136
5137</div>
5138
5139<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]5140<h4>
5141<a name="i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a>
5142</h4>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]5143
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]5144<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]5145
5146<h5>Syntax:</h5>
5147<pre>
Bill Wendling262396b2011-12-09 22:41:40 +0000[diff] [blame]5148 cmpxchg [volatile] &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;cmp&gt;, &lt;ty&gt; &lt;new&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]5149</pre>
5150
5151<h5>Overview:</h5>
5152<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
5153It loads a value in memory and compares it to a given value. If they are
5154equal, it stores a new value into the memory.</p>
5155
5156<h5>Arguments:</h5>
5157<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
5158address to operate on, a value to compare to the value currently be at that
5159address, and a new value to place at that address if the compared values are
5160equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
5161bit width is a power of two greater than or equal to eight and less than
5162or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
5163'<var>&lt;new&gt;</var>' must have the same type, and the type of
5164'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
5165<code>cmpxchg</code> is marked as <code>volatile</code>, then the
5166optimizer is not allowed to modify the number or order of execution
5167of this <code>cmpxchg</code> with other <a href="#volatile">volatile
5168operations</a>.</p>
5169
5170<!-- FIXME: Extend allowed types. -->
5171
5172<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
5173<code>cmpxchg</code> synchronizes with other atomic operations.</p>
5174
5175<p>The optional "<code>singlethread</code>" argument declares that the
5176<code>cmpxchg</code> is only atomic with respect to code (usually signal
5177handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
5178cmpxchg is atomic with respect to all other code in the system.</p>
5179
5180<p>The pointer passed into cmpxchg must have alignment greater than or equal to
5181the size in memory of the operand.
5182
5183<h5>Semantics:</h5>
5184<p>The contents of memory at the location specified by the
5185'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
5186'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
5187'<tt>&lt;new&gt;</tt>' is written. The original value at the location
5188is returned.
5189
5190<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
5191purpose of identifying <a href="#release_sequence">release sequences</a>. A
5192failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
5193parameter determined by dropping any <code>release</code> part of the
5194<code>cmpxchg</code>'s ordering.</p>
5195
5196<!--
5197FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
5198optimization work on ARM.)
5199
5200FIXME: Is a weaker ordering constraint on failure helpful in practice?
5201-->
5202
5203<h5>Example:</h5>
5204<pre>
5205entry:
Bill Wendling262396b2011-12-09 22:41:40 +0000[diff] [blame]5206 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]5207 <a href="#i_br">br</a> label %loop
5208
5209loop:
5210 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
5211 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
Bill Wendling262396b2011-12-09 22:41:40 +0000[diff] [blame]5212 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]5213 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
5214 <a href="#i_br">br</a> i1 %success, label %done, label %loop
5215
5216done:
5217 ...
5218</pre>
5219
5220</div>
5221
5222<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]5223<h4>
5224<a name="i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a>
5225</h4>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]5226
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]5227<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]5228
5229<h5>Syntax:</h5>
5230<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]5231 atomicrmw [volatile] &lt;operation&gt; &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;value&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]5232</pre>
5233
5234<h5>Overview:</h5>
5235<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
5236
5237<h5>Arguments:</h5>
5238<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
5239operation to apply, an address whose value to modify, an argument to the
5240operation. The operation must be one of the following keywords:</p>
5241<ul>
5242 <li>xchg</li>
5243 <li>add</li>
5244 <li>sub</li>
5245 <li>and</li>
5246 <li>nand</li>
5247 <li>or</li>
5248 <li>xor</li>
5249 <li>max</li>
5250 <li>min</li>
5251 <li>umax</li>
5252 <li>umin</li>
5253</ul>
5254
5255<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
5256bit width is a power of two greater than or equal to eight and less than
5257or equal to a target-specific size limit. The type of the
5258'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
5259If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
5260optimizer is not allowed to modify the number or order of execution of this
5261<code>atomicrmw</code> with other <a href="#volatile">volatile
5262 operations</a>.</p>
5263
5264<!-- FIXME: Extend allowed types. -->
5265
5266<h5>Semantics:</h5>
5267<p>The contents of memory at the location specified by the
5268'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
5269back. The original value at the location is returned. The modification is
5270specified by the <var>operation</var> argument:</p>
5271
5272<ul>
5273 <li>xchg: <code>*ptr = val</code></li>
5274 <li>add: <code>*ptr = *ptr + val</code></li>
5275 <li>sub: <code>*ptr = *ptr - val</code></li>
5276 <li>and: <code>*ptr = *ptr &amp; val</code></li>
5277 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
5278 <li>or: <code>*ptr = *ptr | val</code></li>
5279 <li>xor: <code>*ptr = *ptr ^ val</code></li>
5280 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
5281 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
5282 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
5283 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
5284</ul>
5285
5286<h5>Example:</h5>
5287<pre>
5288 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
5289</pre>
5290
5291</div>
5292
5293<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5294<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5295 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5296</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5297
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5298<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5299
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5300<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5301<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5302 &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]5303 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5304 &lt;result&gt; = getelementptr &lt;ptr vector&gt; ptrval, &lt;vector index type&gt; idx
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5305</pre>
5306
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5307<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5308<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]5309 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
5310 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5311
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5312<h5>Arguments:</h5>
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5313<p>The first argument is always a pointer or a vector of pointers,
5314 and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]5315 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5316 elements of the aggregate object are indexed. The interpretation of each
5317 index is dependent on the type being indexed into. The first index always
5318 indexes the pointer value given as the first argument, the second index
5319 indexes a value of the type pointed to (not necessarily the value directly
5320 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]5321 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]5322 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]5323 can never be pointers, since that would require loading the pointer before
5324 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5325
5326<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]5327 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]5328 integer <b>constants</b> are allowed. When indexing into an array, pointer
5329 or vector, integers of any width are allowed, and they are not required to be
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]5330 constant. These integers are treated as signed values where relevant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5331
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5332<p>For example, let's consider a C code fragment and how it gets compiled to
5333 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5334
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5335<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5336struct RT {
5337 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]5338 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5339 char C;
5340};
5341struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]5342 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5343 double Y;
5344 struct RT Z;
5345};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5346
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]5347int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5348 return &amp;s[1].Z.B[5][13];
5349}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5350</pre>
5351
Bill Wendlinga3495392011-12-13 01:07:07 +0000[diff] [blame]5352<p>The LLVM code generated by Clang is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5353
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5354<pre class="doc_code">
Bill Wendlinga3495392011-12-13 01:07:07 +0000[diff] [blame]5355%struct.RT = <a href="#namedtypes">type</a> { i8, [10 x [20 x i32]], i8 }
5356%struct.ST = <a href="#namedtypes">type</a> { i32, double, %struct.RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5357
Bill Wendlinga3495392011-12-13 01:07:07 +0000[diff] [blame]5358define i32* @foo(%struct.ST* %s) nounwind uwtable readnone optsize ssp {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5359entry:
Bill Wendlinga3495392011-12-13 01:07:07 +0000[diff] [blame]5360 %arrayidx = getelementptr inbounds %struct.ST* %s, i64 1, i32 2, i32 1, i64 5, i64 13
5361 ret i32* %arrayidx
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5362}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5363</pre>
5364
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5365<h5>Semantics:</h5>
Bill Wendlinga3495392011-12-13 01:07:07 +0000[diff] [blame]5366<p>In the example above, the first index is indexing into the
5367 '<tt>%struct.ST*</tt>' type, which is a pointer, yielding a
5368 '<tt>%struct.ST</tt>' = '<tt>{ i32, double, %struct.RT }</tt>' type, a
5369 structure. The second index indexes into the third element of the structure,
5370 yielding a '<tt>%struct.RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]], i8 }</tt>'
5371 type, another structure. The third index indexes into the second element of
5372 the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an array. The
5373 two dimensions of the array are subscripted into, yielding an '<tt>i32</tt>'
5374 type. The '<tt>getelementptr</tt>' instruction returns a pointer to this
5375 element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5376
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5377<p>Note that it is perfectly legal to index partially through a structure,
5378 returning a pointer to an inner element. Because of this, the LLVM code for
5379 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5380
Bill Wendlinga3495392011-12-13 01:07:07 +0000[diff] [blame]5381<pre class="doc_code">
5382define i32* @foo(%struct.ST* %s) {
5383 %t1 = getelementptr %struct.ST* %s, i32 1 <i>; yields %struct.ST*:%t1</i>
5384 %t2 = getelementptr %struct.ST* %t1, i32 0, i32 2 <i>; yields %struct.RT*:%t2</i>
5385 %t3 = getelementptr %struct.RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
5386 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
5387 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
5388 ret i32* %t5
5389}
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5390</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]5391
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5392<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohmanbfb056d2011-12-06 03:18:47 +0000[diff] [blame]5393 <tt>getelementptr</tt> is a <a href="#poisonvalues">poison value</a> if the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]5394 base pointer is not an <i>in bounds</i> address of an allocated object,
5395 or if any of the addresses that would be formed by successive addition of
5396 the offsets implied by the indices to the base address with infinitely
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]5397 precise signed arithmetic are not an <i>in bounds</i> address of that
5398 allocated object. The <i>in bounds</i> addresses for an allocated object
5399 are all the addresses that point into the object, plus the address one
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5400 byte past the end.
5401 In cases where the base is a vector of pointers the <tt>inbounds</tt> keyword
5402 applies to each of the computations element-wise. </p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5403
5404<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]5405 the base address with silently-wrapping two's complement arithmetic. If the
5406 offsets have a different width from the pointer, they are sign-extended or
5407 truncated to the width of the pointer. The result value of the
5408 <tt>getelementptr</tt> may be outside the object pointed to by the base
5409 pointer. The result value may not necessarily be used to access memory
5410 though, even if it happens to point into allocated storage. See the
5411 <a href="#pointeraliasing">Pointer Aliasing Rules</a> section for more
5412 information.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5413
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5414<p>The getelementptr instruction is often confusing. For some more insight into
5415 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]5416
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5417<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5418<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5419 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5420 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
5421 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5422 %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]5423 <i>; yields i8*:eptr</i>
5424 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]5425 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]5426 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5427</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5428
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5429<p>In cases where the pointer argument is a vector of pointers, only a
5430 single index may be used, and the number of vector elements has to be
5431 the same. For example: </p>
5432<pre class="doc_code">
5433 %A = getelementptr <4 x i8*> %ptrs, <4 x i64> %offsets,
5434</pre>
5435
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5436</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]5437
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5438</div>
5439
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5440<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5441<h3>
5442 <a name="convertops">Conversion Operations</a>
5443</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5444
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5445<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5446
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5447<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5448 which all take a single operand and a type. They perform various bit
5449 conversions on the operand.</p>
5450
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5451<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5452<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5453 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5454</h4>
5455
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5456<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5457
5458<h5>Syntax:</h5>
5459<pre>
5460 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5461</pre>
5462
5463<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5464<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5465 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5466
5467<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5468<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5469 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5470 of the same number of integers.
5471 The bit size of the <tt>value</tt> must be larger than
5472 the bit size of the destination type, <tt>ty2</tt>.
5473 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5474
5475<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5476<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5477 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5478 source size must be larger than the destination size, <tt>trunc</tt> cannot
5479 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5480
5481<h5>Example:</h5>
5482<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5483 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5484 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5485 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5486 %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]5487</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5488
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5489</div>
5490
5491<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5492<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5493 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5494</h4>
5495
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5496<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5497
5498<h5>Syntax:</h5>
5499<pre>
5500 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5501</pre>
5502
5503<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5504<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5505 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5506
5507
5508<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5509<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5510 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5511 of the same number of integers.
5512 The bit size of the <tt>value</tt> must be smaller than
5513 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5514 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5515
5516<h5>Semantics:</h5>
5517<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]5518 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5519
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]5520<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]5521
5522<h5>Example:</h5>
5523<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5524 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5525 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5526 %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]5527</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5528
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5529</div>
5530
5531<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5532<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5533 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5534</h4>
5535
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5536<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5537
5538<h5>Syntax:</h5>
5539<pre>
5540 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5541</pre>
5542
5543<h5>Overview:</h5>
5544<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5545
5546<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5547<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5548 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5549 of the same number of integers.
5550 The bit size of the <tt>value</tt> must be smaller than
5551 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5552 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5553
5554<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5555<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5556 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5557 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5558
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5559<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]5560
5561<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5562<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5563 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5564 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5565 %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]5566</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5567
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5568</div>
5569
5570<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5571<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5572 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5573</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5574
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5575<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5576
5577<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5578<pre>
5579 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5580</pre>
5581
5582<h5>Overview:</h5>
5583<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5584 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5585
5586<h5>Arguments:</h5>
5587<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5588 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5589 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]5590 <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]5591 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5592
5593<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5594<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5595 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5596 <a href="#t_floating">floating point</a> type. If the value cannot fit
5597 within the destination type, <tt>ty2</tt>, then the results are
5598 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5599
5600<h5>Example:</h5>
5601<pre>
5602 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5603 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5604</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5605
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5606</div>
5607
5608<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5609<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5610 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5611</h4>
5612
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5613<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5614
5615<h5>Syntax:</h5>
5616<pre>
5617 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5618</pre>
5619
5620<h5>Overview:</h5>
5621<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]5622 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5623
5624<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5625<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5626 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5627 a <a href="#t_floating">floating point</a> type to cast it to. The source
5628 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5629
5630<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5631<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5632 <a href="#t_floating">floating point</a> type to a larger
5633 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5634 used to make a <i>no-op cast</i> because it always changes bits. Use
5635 <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]5636
5637<h5>Example:</h5>
5638<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]5639 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5640 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5641</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5642
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5643</div>
5644
5645<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5646<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]5647 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5648</h4>
5649
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5650<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5651
5652<h5>Syntax:</h5>
5653<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5654 &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]5655</pre>
5656
5657<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5658<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5659 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5660
5661<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5662<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5663 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5664 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5665 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5666 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5667
5668<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5669<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5670 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5671 towards zero) unsigned integer value. If the value cannot fit
5672 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5673
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5674<h5>Example:</h5>
5675<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5676 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5677 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5678 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5679</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5680
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5681</div>
5682
5683<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5684<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5685 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5686</h4>
5687
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5688<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5689
5690<h5>Syntax:</h5>
5691<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5692 &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]5693</pre>
5694
5695<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5696<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5697 <a href="#t_floating">floating point</a> <tt>value</tt> to
5698 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5699
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5700<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5701<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5702 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5703 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5704 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5705 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5706
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5707<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5708<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5709 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5710 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5711 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5712
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5713<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5714<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5715 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5716 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5717 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5718</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5719
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5720</div>
5721
5722<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5723<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5724 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5725</h4>
5726
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5727<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5728
5729<h5>Syntax:</h5>
5730<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5731 &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]5732</pre>
5733
5734<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5735<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5736 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5737
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5738<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5739<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]5740 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5741 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5742 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5743 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5744
5745<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5746<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5747 integer quantity and converts it to the corresponding floating point
5748 value. If the value cannot fit in the floating point value, the results are
5749 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5750
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5751<h5>Example:</h5>
5752<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5753 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5754 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5755</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5756
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5757</div>
5758
5759<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5760<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5761 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5762</h4>
5763
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5764<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5765
5766<h5>Syntax:</h5>
5767<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5768 &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]5769</pre>
5770
5771<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5772<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5773 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5774
5775<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5776<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]5777 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5778 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5779 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5780 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5781
5782<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5783<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5784 quantity and converts it to the corresponding floating point value. If the
5785 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5786
5787<h5>Example:</h5>
5788<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5789 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5790 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5791</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5792
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5793</div>
5794
5795<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5796<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5797 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5798</h4>
5799
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5800<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5801
5802<h5>Syntax:</h5>
5803<pre>
5804 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5805</pre>
5806
5807<h5>Overview:</h5>
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5808<p>The '<tt>ptrtoint</tt>' instruction converts the pointer or a vector of
5809 pointers <tt>value</tt> to
5810 the integer (or vector of integers) type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5811
5812<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5813<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5814 must be a a value of type <a href="#t_pointer">pointer</a> or a vector of
5815 pointers, and a type to cast it to
5816 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> or a vector
5817 of integers type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5818
5819<h5>Semantics:</h5>
5820<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5821 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5822 truncating or zero extending that value to the size of the integer type. If
5823 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5824 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5825 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5826 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5827
5828<h5>Example:</h5>
5829<pre>
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5830 %X = ptrtoint i32* %P to i8 <i>; yields truncation on 32-bit architecture</i>
5831 %Y = ptrtoint i32* %P to i64 <i>; yields zero extension on 32-bit architecture</i>
5832 %Z = ptrtoint &lt;4 x i32*&gt; %P to &lt;4 x i64&gt;<i>; yields vector zero extension for a vector of addresses on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5833</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5834
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5835</div>
5836
5837<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5838<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5839 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5840</h4>
5841
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5842<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5843
5844<h5>Syntax:</h5>
5845<pre>
5846 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5847</pre>
5848
5849<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5850<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5851 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5852
5853<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5854<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5855 value to cast, and a type to cast it to, which must be a
5856 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5857
5858<h5>Semantics:</h5>
5859<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5860 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5861 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5862 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5863 than the size of a pointer then a zero extension is done. If they are the
5864 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5865
5866<h5>Example:</h5>
5867<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5868 %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]5869 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5870 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5871 %Z = inttoptr &lt;4 x i32&gt; %G to &lt;4 x i8*&gt;<i>; yields truncation of vector G to four pointers</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5872</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5873
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5874</div>
5875
5876<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5877<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5878 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5879</h4>
5880
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5881<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5882
5883<h5>Syntax:</h5>
5884<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5885 &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]5886</pre>
5887
5888<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5889<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5890 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5891
5892<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5893<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5894 non-aggregate first class value, and a type to cast it to, which must also be
5895 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5896 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5897 identical. If the source type is a pointer, the destination type must also be
5898 a pointer. This instruction supports bitwise conversion of vectors to
5899 integers and to vectors of other types (as long as they have the same
5900 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5901
5902<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5903<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5904 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5905 this conversion. The conversion is done as if the <tt>value</tt> had been
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5906 stored to memory and read back as type <tt>ty2</tt>.
5907 Pointer (or vector of pointers) types may only be converted to other pointer
5908 (or vector of pointers) types with this instruction. To convert
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5909 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5910 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5911
5912<h5>Example:</h5>
5913<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5914 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5915 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5916 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
5917 %Z = bitcast &lt;2 x i32*&gt; %V to &lt;2 x i64*&gt; <i>; yields &lt;2 x i64*&gt;</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5918</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5919
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5920</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5921
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5922</div>
5923
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5924<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5925<h3>
5926 <a name="otherops">Other Operations</a>
5927</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5928
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5929<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5930
5931<p>The instructions in this category are the "miscellaneous" instructions, which
5932 defy better classification.</p>
5933
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5934<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5935<h4>
5936 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5937</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5938
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5939<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5940
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5941<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5942<pre>
5943 &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]5944</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5945
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5946<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5947<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
Nadav Rotem16087692011-12-05 06:29:09 +0000[diff] [blame]5948 boolean values based on comparison of its two integer, integer vector,
5949 pointer, or pointer vector operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5950
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5951<h5>Arguments:</h5>
5952<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5953 the condition code indicating the kind of comparison to perform. It is not a
5954 value, just a keyword. The possible condition code are:</p>
5955
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5956<ol>
5957 <li><tt>eq</tt>: equal</li>
5958 <li><tt>ne</tt>: not equal </li>
5959 <li><tt>ugt</tt>: unsigned greater than</li>
5960 <li><tt>uge</tt>: unsigned greater or equal</li>
5961 <li><tt>ult</tt>: unsigned less than</li>
5962 <li><tt>ule</tt>: unsigned less or equal</li>
5963 <li><tt>sgt</tt>: signed greater than</li>
5964 <li><tt>sge</tt>: signed greater or equal</li>
5965 <li><tt>slt</tt>: signed less than</li>
5966 <li><tt>sle</tt>: signed less or equal</li>
5967</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5968
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5969<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5970 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5971 typed. They must also be identical types.</p>
5972
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5973<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5974<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5975 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5976 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]5977 result, as follows:</p>
5978
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5979<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5980 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5981 <tt>false</tt> otherwise. No sign interpretation is necessary or
5982 performed.</li>
5983
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5984 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5985 <tt>false</tt> otherwise. No sign interpretation is necessary or
5986 performed.</li>
5987
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5988 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5989 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5990
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5991 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5992 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5993 to <tt>op2</tt>.</li>
5994
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5995 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5996 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5997
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5998 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5999 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
6000
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6001 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6002 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
6003
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6004 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6005 <tt>true</tt> if <tt>op1</tt> is greater than or equal
6006 to <tt>op2</tt>.</li>
6007
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6008 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6009 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
6010
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6011 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6012 <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]6013</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6014
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6015<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6016 values are compared as if they were integers.</p>
6017
6018<p>If the operands are integer vectors, then they are compared element by
6019 element. The result is an <tt>i1</tt> vector with the same number of elements
6020 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6021
6022<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6023<pre>
6024 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6025 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
6026 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
6027 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
6028 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
6029 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6030</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]6031
6032<p>Note that the code generator does not yet support vector types with
6033 the <tt>icmp</tt> instruction.</p>
6034
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6035</div>
6036
6037<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6038<h4>
6039 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
6040</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6041
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6042<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6043
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6044<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6045<pre>
6046 &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]6047</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6048
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6049<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6050<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
6051 values based on comparison of its operands.</p>
6052
6053<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]6054(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6055
6056<p>If the operands are floating point vectors, then the result type is a vector
6057 of boolean with the same number of elements as the operands being
6058 compared.</p>
6059
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6060<h5>Arguments:</h5>
6061<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6062 the condition code indicating the kind of comparison to perform. It is not a
6063 value, just a keyword. The possible condition code are:</p>
6064
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6065<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]6066 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6067 <li><tt>oeq</tt>: ordered and equal</li>
6068 <li><tt>ogt</tt>: ordered and greater than </li>
6069 <li><tt>oge</tt>: ordered and greater than or equal</li>
6070 <li><tt>olt</tt>: ordered and less than </li>
6071 <li><tt>ole</tt>: ordered and less than or equal</li>
6072 <li><tt>one</tt>: ordered and not equal</li>
6073 <li><tt>ord</tt>: ordered (no nans)</li>
6074 <li><tt>ueq</tt>: unordered or equal</li>
6075 <li><tt>ugt</tt>: unordered or greater than </li>
6076 <li><tt>uge</tt>: unordered or greater than or equal</li>
6077 <li><tt>ult</tt>: unordered or less than </li>
6078 <li><tt>ule</tt>: unordered or less than or equal</li>
6079 <li><tt>une</tt>: unordered or not equal</li>
6080 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]6081 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6082</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6083
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6084<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6085 <i>unordered</i> means that either operand may be a QNAN.</p>
6086
6087<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
6088 a <a href="#t_floating">floating point</a> type or
6089 a <a href="#t_vector">vector</a> of floating point type. They must have
6090 identical types.</p>
6091
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6092<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]6093<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6094 according to the condition code given as <tt>cond</tt>. If the operands are
6095 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]6096 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6097 follows:</p>
6098
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6099<ol>
6100 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6101
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6102 <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]6103 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
6104
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]6105 <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]6106 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6107
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6108 <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]6109 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
6110
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6111 <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]6112 <tt>op1</tt> is less than <tt>op2</tt>.</li>
6113
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6114 <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]6115 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
6116
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6117 <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]6118 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
6119
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]6120 <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]6121
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6122 <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]6123 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
6124
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6125 <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]6126 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
6127
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6128 <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]6129 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
6130
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6131 <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]6132 <tt>op1</tt> is less than <tt>op2</tt>.</li>
6133
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6134 <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]6135 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
6136
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6137 <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]6138 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
6139
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]6140 <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]6141
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6142 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
6143</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6144
6145<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6146<pre>
6147 &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]6148 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
6149 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
6150 &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]6151</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]6152
6153<p>Note that the code generator does not yet support vector types with
6154 the <tt>fcmp</tt> instruction.</p>
6155
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]6156</div>
6157
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]6158<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6159<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]6160 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6161</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]6162
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6163<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]6164
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]6165<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6166<pre>
6167 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
6168</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]6169
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]6170<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6171<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
6172 SSA graph representing the function.</p>
6173
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]6174<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6175<p>The type of the incoming values is specified with the first type field. After
6176 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
6177 one pair for each predecessor basic block of the current block. Only values
6178 of <a href="#t_firstclass">first class</a> type may be used as the value
6179 arguments to the PHI node. Only labels may be used as the label
6180 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]6181
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6182<p>There must be no non-phi instructions between the start of a basic block and
6183 the PHI instructions: i.e. PHI instructions must be first in a basic
6184 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]6185
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6186<p>For the purposes of the SSA form, the use of each incoming value is deemed to
6187 occur on the edge from the corresponding predecessor block to the current
6188 block (but after any definition of an '<tt>invoke</tt>' instruction's return
6189 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]6190
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]6191<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6192<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6193 specified by the pair corresponding to the predecessor basic block that
6194 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]6195
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]6196<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]6197<pre>
6198Loop: ; Infinite loop that counts from 0 on up...
6199 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
6200 %nextindvar = add i32 %indvar, 1
6201 br label %Loop
6202</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6203
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]6204</div>
6205
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6206<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6207<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6208 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6209</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6210
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6211<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6212
6213<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6214<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]6215 &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>
6216
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6217 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6218</pre>
6219
6220<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6221<p>The '<tt>select</tt>' instruction is used to choose one value based on a
6222 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6223
6224
6225<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6226<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
6227 values indicating the condition, and two values of the
6228 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
6229 vectors and the condition is a scalar, then entire vectors are selected, not
6230 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6231
6232<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6233<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
6234 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6235
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6236<p>If the condition is a vector of i1, then the value arguments must be vectors
6237 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6238
6239<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6240<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]6241 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6242</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]6243
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]6244</div>
6245
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]6246<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6247<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6248 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6249</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6250
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6251<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6252
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6253<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6254<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]6255 &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]6256</pre>
6257
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6258<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6259<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6260
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6261<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6262<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6263
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]6264<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]6265 <li>The optional "tail" marker indicates that the callee function does not
6266 access any allocas or varargs in the caller. Note that calls may be
6267 marked "tail" even if they do not occur before
6268 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
6269 present, the function call is eligible for tail call optimization,
6270 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]6271 optimized into a jump</a>. The code generator may optimize calls marked
6272 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
6273 sibling call optimization</a> when the caller and callee have
6274 matching signatures, or 2) forced tail call optimization when the
6275 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]6276 <ul>
6277 <li>Caller and callee both have the calling
6278 convention <tt>fastcc</tt>.</li>
6279 <li>The call is in tail position (ret immediately follows call and ret
6280 uses value of call or is void).</li>
6281 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]6282 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]6283 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
6284 constraints are met.</a></li>
6285 </ul>
6286 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]6287
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6288 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
6289 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]6290 defaults to using C calling conventions. The calling convention of the
6291 call must match the calling convention of the target function, or else the
6292 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]6293
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6294 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
6295 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
6296 '<tt>inreg</tt>' attributes are valid here.</li>
6297
6298 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
6299 type of the return value. Functions that return no value are marked
6300 <tt><a href="#t_void">void</a></tt>.</li>
6301
6302 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
6303 being invoked. The argument types must match the types implied by this
6304 signature. This type can be omitted if the function is not varargs and if
6305 the function type does not return a pointer to a function.</li>
6306
6307 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
6308 be invoked. In most cases, this is a direct function invocation, but
6309 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
6310 to function value.</li>
6311
6312 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]6313 signature argument types and parameter attributes. All arguments must be
6314 of <a href="#t_firstclass">first class</a> type. If the function
6315 signature indicates the function accepts a variable number of arguments,
6316 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6317
6318 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
6319 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
6320 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]6321</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6322
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6323<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6324<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
6325 a specified function, with its incoming arguments bound to the specified
6326 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
6327 function, control flow continues with the instruction after the function
6328 call, and the return value of the function is bound to the result
6329 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6330
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6331<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6332<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]6333 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6334 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]6335 %X = tail call i32 @foo() <i>; yields i32</i>
6336 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
6337 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]6338
6339 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]6340 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]6341 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
6342 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]6343 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]6344 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]6345</pre>
6346
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]6347<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]6348standard C99 library as being the C99 library functions, and may perform
6349optimizations or generate code for them under that assumption. This is
6350something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6351freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]6352
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6353</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6354
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6355<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6356<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]6357 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6358</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6359
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6360<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6361
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6362<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6363<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6364 &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]6365</pre>
6366
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6367<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6368<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6369 the "variable argument" area of a function call. It is used to implement the
6370 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6371
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6372<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6373<p>This instruction takes a <tt>va_list*</tt> value and the type of the
6374 argument. It returns a value of the specified argument type and increments
6375 the <tt>va_list</tt> to point to the next argument. The actual type
6376 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6377
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6378<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6379<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
6380 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
6381 to the next argument. For more information, see the variable argument
6382 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6383
6384<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]6385 take a variable number of arguments, for example, the <tt>vfprintf</tt>
6386 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6387
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6388<p><tt>va_arg</tt> is an LLVM instruction instead of
6389 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
6390 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6391
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6392<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6393<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
6394
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6395<p>Note that the code generator does not yet fully support va_arg on many
6396 targets. Also, it does not currently support va_arg with aggregate types on
6397 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]6398
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6399</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6400
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6401<!-- _______________________________________________________________________ -->
6402<h4>
6403 <a name="i_landingpad">'<tt>landingpad</tt>' Instruction</a>
6404</h4>
6405
6406<div>
6407
6408<h5>Syntax:</h5>
6409<pre>
Duncan Sands8d6796b2012-01-13 19:59:16 +0000[diff] [blame]6410 &lt;resultval&gt; = landingpad &lt;resultty&gt; personality &lt;type&gt; &lt;pers_fn&gt; &lt;clause&gt;+
6411 &lt;resultval&gt; = landingpad &lt;resultty&gt; personality &lt;type&gt; &lt;pers_fn&gt; cleanup &lt;clause&gt;*
Bill Wendlingbf13ee12011-08-08 08:06:05 +0000[diff] [blame]6412
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6413 &lt;clause&gt; := catch &lt;type&gt; &lt;value&gt;
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6414 &lt;clause&gt; := filter &lt;array constant type&gt; &lt;array constant&gt;
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6415</pre>
6416
6417<h5>Overview:</h5>
6418<p>The '<tt>landingpad</tt>' instruction is used by
6419 <a href="ExceptionHandling.html#overview">LLVM's exception handling
6420 system</a> to specify that a basic block is a landing pad &mdash; one where
6421 the exception lands, and corresponds to the code found in the
6422 <i><tt>catch</tt></i> portion of a <i><tt>try/catch</tt></i> sequence. It
6423 defines values supplied by the personality function (<tt>pers_fn</tt>) upon
6424 re-entry to the function. The <tt>resultval</tt> has the
Duncan Sands8d6796b2012-01-13 19:59:16 +0000[diff] [blame]6425 type <tt>resultty</tt>.</p>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6426
6427<h5>Arguments:</h5>
6428<p>This instruction takes a <tt>pers_fn</tt> value. This is the personality
6429 function associated with the unwinding mechanism. The optional
6430 <tt>cleanup</tt> flag indicates that the landing pad block is a cleanup.</p>
6431
6432<p>A <tt>clause</tt> begins with the clause type &mdash; <tt>catch</tt>
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6433 or <tt>filter</tt> &mdash; and contains the global variable representing the
6434 "type" that may be caught or filtered respectively. Unlike the
6435 <tt>catch</tt> clause, the <tt>filter</tt> clause takes an array constant as
6436 its argument. Use "<tt>[0 x i8**] undef</tt>" for a filter which cannot
6437 throw. The '<tt>landingpad</tt>' instruction must contain <em>at least</em>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6438 one <tt>clause</tt> or the <tt>cleanup</tt> flag.</p>
6439
6440<h5>Semantics:</h5>
6441<p>The '<tt>landingpad</tt>' instruction defines the values which are set by the
6442 personality function (<tt>pers_fn</tt>) upon re-entry to the function, and
6443 therefore the "result type" of the <tt>landingpad</tt> instruction. As with
6444 calling conventions, how the personality function results are represented in
6445 LLVM IR is target specific.</p>
6446
Bill Wendlingb7a01352011-08-03 17:17:06 +0000[diff] [blame]6447<p>The clauses are applied in order from top to bottom. If two
6448 <tt>landingpad</tt> instructions are merged together through inlining, the
Duncan Sands8d6796b2012-01-13 19:59:16 +0000[diff] [blame]6449 clauses from the calling function are appended to the list of clauses.
6450 When the call stack is being unwound due to an exception being thrown, the
6451 exception is compared against each <tt>clause</tt> in turn. If it doesn't
6452 match any of the clauses, and the <tt>cleanup</tt> flag is not set, then
6453 unwinding continues further up the call stack.</p>
Bill Wendlingb7a01352011-08-03 17:17:06 +0000[diff] [blame]6454
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6455<p>The <tt>landingpad</tt> instruction has several restrictions:</p>
6456
6457<ul>
6458 <li>A landing pad block is a basic block which is the unwind destination of an
6459 '<tt>invoke</tt>' instruction.</li>
6460 <li>A landing pad block must have a '<tt>landingpad</tt>' instruction as its
6461 first non-PHI instruction.</li>
6462 <li>There can be only one '<tt>landingpad</tt>' instruction within the landing
6463 pad block.</li>
6464 <li>A basic block that is not a landing pad block may not include a
6465 '<tt>landingpad</tt>' instruction.</li>
6466 <li>All '<tt>landingpad</tt>' instructions in a function must have the same
6467 personality function.</li>
6468</ul>
6469
6470<h5>Example:</h5>
6471<pre>
6472 ;; A landing pad which can catch an integer.
6473 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6474 catch i8** @_ZTIi
6475 ;; A landing pad that is a cleanup.
6476 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6477 cleanup
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6478 ;; A landing pad which can catch an integer and can only throw a double.
6479 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6480 catch i8** @_ZTIi
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6481 filter [1 x i8**] [@_ZTId]
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6482</pre>
6483
6484</div>
6485
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6486</div>
6487
6488</div>
6489
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6490<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6491<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]6492<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6493
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6494<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6495
6496<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6497 well known names and semantics and are required to follow certain
6498 restrictions. Overall, these intrinsics represent an extension mechanism for
6499 the LLVM language that does not require changing all of the transformations
6500 in LLVM when adding to the language (or the bitcode reader/writer, the
6501 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6502
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]6503<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6504 prefix is reserved in LLVM for intrinsic names; thus, function names may not
6505 begin with this prefix. Intrinsic functions must always be external
6506 functions: you cannot define the body of intrinsic functions. Intrinsic
6507 functions may only be used in call or invoke instructions: it is illegal to
6508 take the address of an intrinsic function. Additionally, because intrinsic
6509 functions are part of the LLVM language, it is required if any are added that
6510 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6511
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6512<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
6513 family of functions that perform the same operation but on different data
6514 types. Because LLVM can represent over 8 million different integer types,
6515 overloading is used commonly to allow an intrinsic function to operate on any
6516 integer type. One or more of the argument types or the result type can be
6517 overloaded to accept any integer type. Argument types may also be defined as
6518 exactly matching a previous argument's type or the result type. This allows
6519 an intrinsic function which accepts multiple arguments, but needs all of them
6520 to be of the same type, to only be overloaded with respect to a single
6521 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6522
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6523<p>Overloaded intrinsics will have the names of its overloaded argument types
6524 encoded into its function name, each preceded by a period. Only those types
6525 which are overloaded result in a name suffix. Arguments whose type is matched
6526 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6527 can take an integer of any width and returns an integer of exactly the same
6528 integer width. This leads to a family of functions such as
6529 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6530 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6531 suffix is required. Because the argument's type is matched against the return
6532 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6533
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6534<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6535 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6536
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6537<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6538<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6539 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6540</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6541
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6542<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6543
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6544<p>Variable argument support is defined in LLVM with
6545 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6546 intrinsic functions. These functions are related to the similarly named
6547 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6548
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6549<p>All of these functions operate on arguments that use a target-specific value
6550 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6551 not define what this type is, so all transformations should be prepared to
6552 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6553
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]6554<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]6555 instruction and the variable argument handling intrinsic functions are
6556 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6557
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]6558<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6559define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6560 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6561 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6562 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6563 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6564
6565 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6566 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6567
6568 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6569 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6570 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6571 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6572 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6573
6574 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6575 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6576 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6577}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6578
6579declare void @llvm.va_start(i8*)
6580declare void @llvm.va_copy(i8*, i8*)
6581declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6582</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6583
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6584<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6585<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6586 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6587</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6588
6589
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6590<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6591
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6592<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6593<pre>
6594 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6595</pre>
6596
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6597<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6598<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6599 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]6600
6601<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6602<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]6603
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6604<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6605<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]6606 macro available in C. In a target-dependent way, it initializes
6607 the <tt>va_list</tt> element to which the argument points, so that the next
6608 call to <tt>va_arg</tt> will produce the first variable argument passed to
6609 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6610 need to know the last argument of the function as the compiler can figure
6611 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6612
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6613</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6614
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6615<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6616<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6617 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6618</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6619
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6620<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6621
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6622<h5>Syntax:</h5>
6623<pre>
6624 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6625</pre>
6626
6627<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6628<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6629 which has been initialized previously
6630 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6631 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6632
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6633<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6634<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]6635
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6636<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6637<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]6638 macro available in C. In a target-dependent way, it destroys
6639 the <tt>va_list</tt> element to which the argument points. Calls
6640 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6641 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6642 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6643
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6644</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6645
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6646<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6647<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6648 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6649</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6650
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6651<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6652
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6653<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6654<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6655 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6656</pre>
6657
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6658<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6659<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6660 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6661
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6662<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6663<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]6664 The second argument is a pointer to a <tt>va_list</tt> element to copy
6665 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6666
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6667<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6668<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]6669 macro available in C. In a target-dependent way, it copies the
6670 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6671 element. This intrinsic is necessary because
6672 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6673 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6674
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6675</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6676
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6677</div>
6678
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6679<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6680<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6681 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6682</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6683
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6684<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6685
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6686<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6687Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6688intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6689roots on the stack</a>, as well as garbage collector implementations that
6690require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6691barriers. Front-ends for type-safe garbage collected languages should generate
6692these intrinsics to make use of the LLVM garbage collectors. For more details,
6693see <a href="GarbageCollection.html">Accurate Garbage Collection with
6694LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6695
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6696<p>The garbage collection intrinsics only operate on objects in the generic
6697 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6698
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6699<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6700<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6701 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6702</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6703
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6704<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6705
6706<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6707<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6708 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6709</pre>
6710
6711<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]6712<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]6713 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6714
6715<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6716<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6717 root pointer. The second pointer (which must be either a constant or a
6718 global value address) contains the meta-data to be associated with the
6719 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6720
6721<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]6722<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]6723 location. At compile-time, the code generator generates information to allow
6724 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6725 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6726 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6727
6728</div>
6729
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6730<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6731<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6732 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6733</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6734
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6735<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6736
6737<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6738<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6739 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6740</pre>
6741
6742<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6743<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6744 locations, allowing garbage collector implementations that require read
6745 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6746
6747<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6748<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]6749 allocated from the garbage collector. The first object is a pointer to the
6750 start of the referenced object, if needed by the language runtime (otherwise
6751 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6752
6753<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6754<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6755 instruction, but may be replaced with substantially more complex code by the
6756 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6757 may only be used in a function which <a href="#gc">specifies a GC
6758 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6759
6760</div>
6761
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6762<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6763<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6764 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6765</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6766
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6767<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6768
6769<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6770<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6771 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6772</pre>
6773
6774<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6775<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6776 locations, allowing garbage collector implementations that require write
6777 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6778
6779<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6780<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]6781 object to store it to, and the third is the address of the field of Obj to
6782 store to. If the runtime does not require a pointer to the object, Obj may
6783 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6784
6785<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6786<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6787 instruction, but may be replaced with substantially more complex code by the
6788 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6789 may only be used in a function which <a href="#gc">specifies a GC
6790 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6791
6792</div>
6793
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6794</div>
6795
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6796<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6797<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6798 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6799</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6800
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6801<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6802
6803<p>These intrinsics are provided by LLVM to expose special features that may
6804 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6805
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6806<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6807<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6808 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6809</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6810
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6811<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6812
6813<h5>Syntax:</h5>
6814<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6815 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6816</pre>
6817
6818<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6819<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6820 target-specific value indicating the return address of the current function
6821 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6822
6823<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6824<p>The argument to this intrinsic indicates which function to return the address
6825 for. Zero indicates the calling function, one indicates its caller, etc.
6826 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6827
6828<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6829<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6830 indicating the return address of the specified call frame, or zero if it
6831 cannot be identified. The value returned by this intrinsic is likely to be
6832 incorrect or 0 for arguments other than zero, so it should only be used for
6833 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6834
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6835<p>Note that calling this intrinsic does not prevent function inlining or other
6836 aggressive transformations, so the value returned may not be that of the
6837 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6838
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6839</div>
6840
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6841<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6842<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6843 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6844</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6845
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6846<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6847
6848<h5>Syntax:</h5>
6849<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6850 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6851</pre>
6852
6853<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6854<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6855 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6856
6857<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6858<p>The argument to this intrinsic indicates which function to return the frame
6859 pointer for. Zero indicates the calling function, one indicates its caller,
6860 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6861
6862<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6863<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6864 indicating the frame address of the specified call frame, or zero if it
6865 cannot be identified. The value returned by this intrinsic is likely to be
6866 incorrect or 0 for arguments other than zero, so it should only be used for
6867 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6868
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6869<p>Note that calling this intrinsic does not prevent function inlining or other
6870 aggressive transformations, so the value returned may not be that of the
6871 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6872
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6873</div>
6874
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6875<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6876<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6877 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6878</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6879
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6880<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6881
6882<h5>Syntax:</h5>
6883<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6884 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6885</pre>
6886
6887<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6888<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6889 of the function stack, for use
6890 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6891 useful for implementing language features like scoped automatic variable
6892 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6893
6894<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6895<p>This intrinsic returns a opaque pointer value that can be passed
6896 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6897 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6898 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6899 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6900 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6901 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6902
6903</div>
6904
6905<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6906<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6907 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6908</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6909
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6910<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6911
6912<h5>Syntax:</h5>
6913<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6914 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6915</pre>
6916
6917<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6918<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6919 the function stack to the state it was in when the
6920 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6921 executed. This is useful for implementing language features like scoped
6922 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6923
6924<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6925<p>See the description
6926 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6927
6928</div>
6929
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6930<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6931<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6932 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6933</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6934
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6935<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6936
6937<h5>Syntax:</h5>
6938<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6939 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]6940</pre>
6941
6942<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6943<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6944 insert a prefetch instruction if supported; otherwise, it is a noop.
6945 Prefetches have no effect on the behavior of the program but can change its
6946 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6947
6948<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6949<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6950 specifier determining if the fetch should be for a read (0) or write (1),
6951 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6952 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6953 specifies whether the prefetch is performed on the data (1) or instruction (0)
6954 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6955 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6956
6957<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6958<p>This intrinsic does not modify the behavior of the program. In particular,
6959 prefetches cannot trap and do not produce a value. On targets that support
6960 this intrinsic, the prefetch can provide hints to the processor cache for
6961 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6962
6963</div>
6964
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6965<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6966<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6967 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6968</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6969
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6970<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6971
6972<h5>Syntax:</h5>
6973<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6974 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6975</pre>
6976
6977<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6978<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6979 Counter (PC) in a region of code to simulators and other tools. The method
6980 is target specific, but it is expected that the marker will use exported
6981 symbols to transmit the PC of the marker. The marker makes no guarantees
6982 that it will remain with any specific instruction after optimizations. It is
6983 possible that the presence of a marker will inhibit optimizations. The
6984 intended use is to be inserted after optimizations to allow correlations of
6985 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6986
6987<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6988<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6989
6990<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6991<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6992 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6993
6994</div>
6995
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6996<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6997<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6998 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6999</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]7000
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7001<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]7002
7003<h5>Syntax:</h5>
7004<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7005 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]7006</pre>
7007
7008<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7009<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
7010 counter register (or similar low latency, high accuracy clocks) on those
7011 targets that support it. On X86, it should map to RDTSC. On Alpha, it
7012 should map to RPCC. As the backing counters overflow quickly (on the order
7013 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]7014
7015<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7016<p>When directly supported, reading the cycle counter should not modify any
7017 memory. Implementations are allowed to either return a application specific
7018 value or a system wide value. On backends without support, this is lowered
7019 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]7020
7021</div>
7022
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7023</div>
7024
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7025<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7026<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7027 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7028</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7029
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7030<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7031
7032<p>LLVM provides intrinsics for a few important standard C library functions.
7033 These intrinsics allow source-language front-ends to pass information about
7034 the alignment of the pointer arguments to the code generator, providing
7035 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7036
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7037<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7038<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7039 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7040</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7041
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7042<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7043
7044<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7045<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]7046 integer bit width and for different address spaces. Not all targets support
7047 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7048
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7049<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]7050 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]7051 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]7052 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]7053 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7054</pre>
7055
7056<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7057<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
7058 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7059
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7060<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7061 intrinsics do not return a value, takes extra alignment/isvolatile arguments
7062 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7063
7064<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7065
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7066<p>The first argument is a pointer to the destination, the second is a pointer
7067 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7068 number of bytes to copy, the fourth argument is the alignment of the
7069 source and destination locations, and the fifth is a boolean indicating a
7070 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7071
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7072<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]7073 then the caller guarantees that both the source and destination pointers are
7074 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]7075
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]7076<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
7077 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
7078 The detailed access behavior is not very cleanly specified and it is unwise
7079 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7080
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7081<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7082
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7083<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
7084 source location to the destination location, which are not allowed to
7085 overlap. It copies "len" bytes of memory over. If the argument is known to
7086 be aligned to some boundary, this can be specified as the fourth argument,
7087 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7088
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]7089</div>
7090
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7091<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7092<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7093 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7094</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7095
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7096<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7097
7098<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]7099<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]7100 width and for different address space. Not all targets support all bit
7101 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7102
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7103<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]7104 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]7105 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]7106 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]7107 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7108</pre>
7109
7110<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7111<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
7112 source location to the destination location. It is similar to the
7113 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
7114 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7115
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7116<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7117 intrinsics do not return a value, takes extra alignment/isvolatile arguments
7118 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7119
7120<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7121
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7122<p>The first argument is a pointer to the destination, the second is a pointer
7123 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7124 number of bytes to copy, the fourth argument is the alignment of the
7125 source and destination locations, and the fifth is a boolean indicating a
7126 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7127
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7128<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]7129 then the caller guarantees that the source and destination pointers are
7130 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]7131
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]7132<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
7133 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
7134 The detailed access behavior is not very cleanly specified and it is unwise
7135 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7136
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7137<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7138
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7139<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
7140 source location to the destination location, which may overlap. It copies
7141 "len" bytes of memory over. If the argument is known to be aligned to some
7142 boundary, this can be specified as the fourth argument, otherwise it should
7143 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7144
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]7145</div>
7146
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7147<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7148<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7149 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7150</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7151
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7152<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7153
7154<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]7155<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]7156 width and for different address spaces. However, not all targets support all
7157 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7158
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7159<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]7160 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]7161 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]7162 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]7163 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7164</pre>
7165
7166<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7167<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
7168 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7169
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7170<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]7171 intrinsic does not return a value and takes extra alignment/volatile
7172 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7173
7174<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7175<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]7176 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7177 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]7178 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7179
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7180<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]7181 then the caller guarantees that the destination pointer is aligned to that
7182 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7183
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]7184<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
7185 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
7186 The detailed access behavior is not very cleanly specified and it is unwise
7187 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]7188
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7189<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7190<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
7191 at the destination location. If the argument is known to be aligned to some
7192 boundary, this can be specified as the fourth argument, otherwise it should
7193 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7194
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]7195</div>
7196
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]7197<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7198<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7199 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7200</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]7201
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7202<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]7203
7204<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7205<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
7206 floating point or vector of floating point type. Not all targets support all
7207 types however.</p>
7208
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]7209<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]7210 declare float @llvm.sqrt.f32(float %Val)
7211 declare double @llvm.sqrt.f64(double %Val)
7212 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
7213 declare fp128 @llvm.sqrt.f128(fp128 %Val)
7214 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]7215</pre>
7216
7217<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7218<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
7219 returning the same value as the libm '<tt>sqrt</tt>' functions would.
7220 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
7221 behavior for negative numbers other than -0.0 (which allows for better
7222 optimization, because there is no need to worry about errno being
7223 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]7224
7225<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7226<p>The argument and return value are floating point numbers of the same
7227 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]7228
7229<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7230<p>This function returns the sqrt of the specified operand if it is a
7231 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]7232
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]7233</div>
7234
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7235<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7236<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7237 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7238</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7239
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7240<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7241
7242<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7243<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
7244 floating point or vector of floating point type. Not all targets support all
7245 types however.</p>
7246
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7247<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]7248 declare float @llvm.powi.f32(float %Val, i32 %power)
7249 declare double @llvm.powi.f64(double %Val, i32 %power)
7250 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
7251 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
7252 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7253</pre>
7254
7255<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7256<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
7257 specified (positive or negative) power. The order of evaluation of
7258 multiplications is not defined. When a vector of floating point type is
7259 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7260
7261<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7262<p>The second argument is an integer power, and the first is a value to raise to
7263 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7264
7265<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7266<p>This function returns the first value raised to the second power with an
7267 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7268
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]7269</div>
7270
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7271<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7272<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7273 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7274</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7275
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7276<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7277
7278<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7279<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
7280 floating point or vector of floating point type. Not all targets support all
7281 types however.</p>
7282
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7283<pre>
7284 declare float @llvm.sin.f32(float %Val)
7285 declare double @llvm.sin.f64(double %Val)
7286 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
7287 declare fp128 @llvm.sin.f128(fp128 %Val)
7288 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
7289</pre>
7290
7291<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7292<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7293
7294<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7295<p>The argument and return value are floating point numbers of the same
7296 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7297
7298<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7299<p>This function returns the sine of the specified operand, returning the same
7300 values as the libm <tt>sin</tt> functions would, and handles error conditions
7301 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7302
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7303</div>
7304
7305<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7306<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7307 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7308</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7309
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7310<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7311
7312<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7313<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
7314 floating point or vector of floating point type. Not all targets support all
7315 types however.</p>
7316
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7317<pre>
7318 declare float @llvm.cos.f32(float %Val)
7319 declare double @llvm.cos.f64(double %Val)
7320 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
7321 declare fp128 @llvm.cos.f128(fp128 %Val)
7322 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
7323</pre>
7324
7325<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7326<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7327
7328<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7329<p>The argument and return value are floating point numbers of the same
7330 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7331
7332<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7333<p>This function returns the cosine of the specified operand, returning the same
7334 values as the libm <tt>cos</tt> functions would, and handles error conditions
7335 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7336
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7337</div>
7338
7339<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7340<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7341 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7342</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7343
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7344<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7345
7346<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7347<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
7348 floating point or vector of floating point type. Not all targets support all
7349 types however.</p>
7350
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7351<pre>
7352 declare float @llvm.pow.f32(float %Val, float %Power)
7353 declare double @llvm.pow.f64(double %Val, double %Power)
7354 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
7355 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
7356 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
7357</pre>
7358
7359<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7360<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
7361 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7362
7363<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7364<p>The second argument is a floating point power, and the first is a value to
7365 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7366
7367<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7368<p>This function returns the first value raised to the second power, returning
7369 the same values as the libm <tt>pow</tt> functions would, and handles error
7370 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7371
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]7372</div>
7373
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]7374<!-- _______________________________________________________________________ -->
7375<h4>
7376 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
7377</h4>
7378
7379<div>
7380
7381<h5>Syntax:</h5>
7382<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
7383 floating point or vector of floating point type. Not all targets support all
7384 types however.</p>
7385
7386<pre>
7387 declare float @llvm.exp.f32(float %Val)
7388 declare double @llvm.exp.f64(double %Val)
7389 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
7390 declare fp128 @llvm.exp.f128(fp128 %Val)
7391 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
7392</pre>
7393
7394<h5>Overview:</h5>
7395<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
7396
7397<h5>Arguments:</h5>
7398<p>The argument and return value are floating point numbers of the same
7399 type.</p>
7400
7401<h5>Semantics:</h5>
7402<p>This function returns the same values as the libm <tt>exp</tt> functions
7403 would, and handles error conditions in the same way.</p>
7404
7405</div>
7406
7407<!-- _______________________________________________________________________ -->
7408<h4>
7409 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
7410</h4>
7411
7412<div>
7413
7414<h5>Syntax:</h5>
7415<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
7416 floating point or vector of floating point type. Not all targets support all
7417 types however.</p>
7418
7419<pre>
7420 declare float @llvm.log.f32(float %Val)
7421 declare double @llvm.log.f64(double %Val)
7422 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
7423 declare fp128 @llvm.log.f128(fp128 %Val)
7424 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
7425</pre>
7426
7427<h5>Overview:</h5>
7428<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
7429
7430<h5>Arguments:</h5>
7431<p>The argument and return value are floating point numbers of the same
7432 type.</p>
7433
7434<h5>Semantics:</h5>
7435<p>This function returns the same values as the libm <tt>log</tt> functions
7436 would, and handles error conditions in the same way.</p>
7437
Nick Lewycky1c929be2011-10-31 01:32:21 +0000[diff] [blame]7438</div>
7439
7440<!-- _______________________________________________________________________ -->
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]7441<h4>
7442 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
7443</h4>
7444
7445<div>
7446
7447<h5>Syntax:</h5>
7448<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
7449 floating point or vector of floating point type. Not all targets support all
7450 types however.</p>
7451
7452<pre>
7453 declare float @llvm.fma.f32(float %a, float %b, float %c)
7454 declare double @llvm.fma.f64(double %a, double %b, double %c)
7455 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
7456 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
7457 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
7458</pre>
7459
7460<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]7461<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]7462 operation.</p>
7463
7464<h5>Arguments:</h5>
7465<p>The argument and return value are floating point numbers of the same
7466 type.</p>
7467
7468<h5>Semantics:</h5>
7469<p>This function returns the same values as the libm <tt>fma</tt> functions
7470 would.</p>
7471
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]7472</div>
7473
NAKAMURA Takumi4b2e07a2011-10-31 13:04:26 +0000[diff] [blame]7474</div>
7475
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7476<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7477<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7478 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7479</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7480
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7481<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7482
7483<p>LLVM provides intrinsics for a few important bit manipulation operations.
7484 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7485
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7486<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7487<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7488 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7489</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7490
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7491<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7492
7493<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7494<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7495 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
7496
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7497<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7498 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
7499 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
7500 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7501</pre>
7502
7503<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7504<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
7505 values with an even number of bytes (positive multiple of 16 bits). These
7506 are useful for performing operations on data that is not in the target's
7507 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7508
7509<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7510<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
7511 and low byte of the input i16 swapped. Similarly,
7512 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
7513 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
7514 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
7515 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
7516 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
7517 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7518
7519</div>
7520
7521<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7522<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]7523 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7524</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7525
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7526<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7527
7528<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7529<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]7530 width, or on any vector with integer elements. Not all targets support all
7531 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7532
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7533<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7534 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7535 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7536 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7537 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7538 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7539 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]7540</pre>
7541
7542<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7543<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7544 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7545
7546<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7547<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]7548 integer type, or a vector with integer elements.
7549 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7550
7551<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7552<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7553 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7554
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7555</div>
7556
7557<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7558<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7559 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7560</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7561
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7562<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7563
7564<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7565<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]7566 integer bit width, or any vector whose elements are integers. Not all
7567 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7568
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7569<pre>
Chandler Carruth48b0bbf2011-12-12 04:36:04 +0000[diff] [blame]7570 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7571 declare i16 @llvm.ctlz.i16 (i16 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7572 declare i32 @llvm.ctlz.i32 (i32 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7573 declare i64 @llvm.ctlz.i64 (i64 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7574 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7575 declase &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7576</pre>
7577
7578<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7579<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7580 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7581
7582<h5>Arguments:</h5>
Chandler Carruth48b0bbf2011-12-12 04:36:04 +0000[diff] [blame]7583<p>The first argument is the value to be counted. This argument may be of any
7584 integer type, or a vectory with integer element type. The return type
7585 must match the first argument type.</p>
7586
7587<p>The second argument must be a constant and is a flag to indicate whether the
7588 intrinsic should ensure that a zero as the first argument produces a defined
7589 result. Historically some architectures did not provide a defined result for
7590 zero values as efficiently, and many algorithms are now predicated on
7591 avoiding zero-value inputs.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7592
7593<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7594<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Chandler Carruth48b0bbf2011-12-12 04:36:04 +0000[diff] [blame]7595 zeros in a variable, or within each element of the vector.
7596 If <tt>src == 0</tt> then the result is the size in bits of the type of
7597 <tt>src</tt> if <tt>is_zero_undef == 0</tt> and <tt>undef</tt> otherwise.
7598 For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7599
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7600</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]7601
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7602<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7603<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7604 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7605</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7606
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7607<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7608
7609<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7610<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]7611 integer bit width, or any vector of integer elements. Not all targets
7612 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7613
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7614<pre>
Chandler Carruth48b0bbf2011-12-12 04:36:04 +0000[diff] [blame]7615 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7616 declare i16 @llvm.cttz.i16 (i16 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7617 declare i32 @llvm.cttz.i32 (i32 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7618 declare i64 @llvm.cttz.i64 (i64 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7619 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7620 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7621</pre>
7622
7623<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7624<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7625 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7626
7627<h5>Arguments:</h5>
Chandler Carruth48b0bbf2011-12-12 04:36:04 +0000[diff] [blame]7628<p>The first argument is the value to be counted. This argument may be of any
7629 integer type, or a vectory with integer element type. The return type
7630 must match the first argument type.</p>
7631
7632<p>The second argument must be a constant and is a flag to indicate whether the
7633 intrinsic should ensure that a zero as the first argument produces a defined
7634 result. Historically some architectures did not provide a defined result for
7635 zero values as efficiently, and many algorithms are now predicated on
7636 avoiding zero-value inputs.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7637
7638<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7639<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7640 zeros in a variable, or within each element of a vector.
Chandler Carruth48b0bbf2011-12-12 04:36:04 +0000[diff] [blame]7641 If <tt>src == 0</tt> then the result is the size in bits of the type of
7642 <tt>src</tt> if <tt>is_zero_undef == 0</tt> and <tt>undef</tt> otherwise.
7643 For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7644
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7645</div>
7646
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7647</div>
7648
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7649<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7650<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7651 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7652</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7653
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7654<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7655
7656<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7657
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7658<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7659<h4>
7660 <a name="int_sadd_overflow">
7661 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7662 </a>
7663</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7664
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7665<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7666
7667<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7668<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]7669 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7670
7671<pre>
7672 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7673 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7674 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7675</pre>
7676
7677<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7678<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7679 a signed addition of the two arguments, and indicate whether an overflow
7680 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7681
7682<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7683<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]7684 be of integer types of any bit width, but they must have the same bit
7685 width. The second element of the result structure must be of
7686 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7687 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7688
7689<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7690<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7691 a signed addition of the two variables. They return a structure &mdash; the
7692 first element of which is the signed summation, and the second element of
7693 which is a bit specifying if the signed summation resulted in an
7694 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7695
7696<h5>Examples:</h5>
7697<pre>
7698 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7699 %sum = extractvalue {i32, i1} %res, 0
7700 %obit = extractvalue {i32, i1} %res, 1
7701 br i1 %obit, label %overflow, label %normal
7702</pre>
7703
7704</div>
7705
7706<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7707<h4>
7708 <a name="int_uadd_overflow">
7709 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7710 </a>
7711</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7712
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7713<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7714
7715<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7716<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]7717 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7718
7719<pre>
7720 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7721 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7722 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7723</pre>
7724
7725<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7726<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7727 an unsigned addition of the two arguments, and indicate whether a carry
7728 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7729
7730<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7731<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]7732 be of integer types of any bit width, but they must have the same bit
7733 width. The second element of the result structure must be of
7734 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7735 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7736
7737<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7738<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7739 an unsigned addition of the two arguments. They return a structure &mdash;
7740 the first element of which is the sum, and the second element of which is a
7741 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7742
7743<h5>Examples:</h5>
7744<pre>
7745 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7746 %sum = extractvalue {i32, i1} %res, 0
7747 %obit = extractvalue {i32, i1} %res, 1
7748 br i1 %obit, label %carry, label %normal
7749</pre>
7750
7751</div>
7752
7753<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7754<h4>
7755 <a name="int_ssub_overflow">
7756 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7757 </a>
7758</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7759
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7760<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7761
7762<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7763<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]7764 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7765
7766<pre>
7767 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7768 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7769 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7770</pre>
7771
7772<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7773<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7774 a signed subtraction of the two arguments, and indicate whether an overflow
7775 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7776
7777<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7778<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]7779 be of integer types of any bit width, but they must have the same bit
7780 width. The second element of the result structure must be of
7781 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7782 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7783
7784<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7785<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7786 a signed subtraction of the two arguments. They return a structure &mdash;
7787 the first element of which is the subtraction, and the second element of
7788 which is a bit specifying if the signed subtraction resulted in an
7789 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7790
7791<h5>Examples:</h5>
7792<pre>
7793 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7794 %sum = extractvalue {i32, i1} %res, 0
7795 %obit = extractvalue {i32, i1} %res, 1
7796 br i1 %obit, label %overflow, label %normal
7797</pre>
7798
7799</div>
7800
7801<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7802<h4>
7803 <a name="int_usub_overflow">
7804 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7805 </a>
7806</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7807
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7808<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7809
7810<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7811<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]7812 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7813
7814<pre>
7815 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7816 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7817 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7818</pre>
7819
7820<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7821<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7822 an unsigned subtraction of the two arguments, and indicate whether an
7823 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7824
7825<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7826<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]7827 be of integer types of any bit width, but they must have the same bit
7828 width. The second element of the result structure must be of
7829 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7830 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7831
7832<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7833<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7834 an unsigned subtraction of the two arguments. They return a structure &mdash;
7835 the first element of which is the subtraction, and the second element of
7836 which is a bit specifying if the unsigned subtraction resulted in an
7837 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7838
7839<h5>Examples:</h5>
7840<pre>
7841 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7842 %sum = extractvalue {i32, i1} %res, 0
7843 %obit = extractvalue {i32, i1} %res, 1
7844 br i1 %obit, label %overflow, label %normal
7845</pre>
7846
7847</div>
7848
7849<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7850<h4>
7851 <a name="int_smul_overflow">
7852 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7853 </a>
7854</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7855
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7856<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7857
7858<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7859<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]7860 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7861
7862<pre>
7863 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7864 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7865 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7866</pre>
7867
7868<h5>Overview:</h5>
7869
7870<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7871 a signed multiplication of the two arguments, and indicate whether an
7872 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7873
7874<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7875<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]7876 be of integer types of any bit width, but they must have the same bit
7877 width. The second element of the result structure must be of
7878 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7879 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7880
7881<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7882<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7883 a signed multiplication of the two arguments. They return a structure &mdash;
7884 the first element of which is the multiplication, and the second element of
7885 which is a bit specifying if the signed multiplication resulted in an
7886 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7887
7888<h5>Examples:</h5>
7889<pre>
7890 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7891 %sum = extractvalue {i32, i1} %res, 0
7892 %obit = extractvalue {i32, i1} %res, 1
7893 br i1 %obit, label %overflow, label %normal
7894</pre>
7895
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7896</div>
7897
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7898<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7899<h4>
7900 <a name="int_umul_overflow">
7901 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7902 </a>
7903</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7904
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7905<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7906
7907<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7908<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]7909 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7910
7911<pre>
7912 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7913 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7914 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7915</pre>
7916
7917<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7918<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7919 a unsigned multiplication of the two arguments, and indicate whether an
7920 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7921
7922<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7923<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]7924 be of integer types of any bit width, but they must have the same bit
7925 width. The second element of the result structure must be of
7926 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7927 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7928
7929<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7930<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7931 an unsigned multiplication of the two arguments. They return a structure
7932 &mdash; the first element of which is the multiplication, and the second
7933 element of which is a bit specifying if the unsigned multiplication resulted
7934 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7935
7936<h5>Examples:</h5>
7937<pre>
7938 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7939 %sum = extractvalue {i32, i1} %res, 0
7940 %obit = extractvalue {i32, i1} %res, 1
7941 br i1 %obit, label %overflow, label %normal
7942</pre>
7943
7944</div>
7945
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7946</div>
7947
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7948<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7949<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7950 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7951</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7952
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7953<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7954
Tobias Grosser057beb82012-05-24 15:59:06 +0000[diff] [blame]7955<p>For most target platforms, half precision floating point is a storage-only
7956 format. This means that it is
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7957 a dense encoding (in memory) but does not support computation in the
7958 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7959
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7960<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7961 value as an i16, then convert it to float with <a
7962 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7963 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7964 double etc). To store the value back to memory, it is first converted to
7965 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7966 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7967 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7968
7969<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7970<h4>
7971 <a name="int_convert_to_fp16">
7972 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7973 </a>
7974</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7975
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7976<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7977
7978<h5>Syntax:</h5>
7979<pre>
7980 declare i16 @llvm.convert.to.fp16(f32 %a)
7981</pre>
7982
7983<h5>Overview:</h5>
7984<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7985 a conversion from single precision floating point format to half precision
7986 floating point format.</p>
7987
7988<h5>Arguments:</h5>
7989<p>The intrinsic function contains single argument - the value to be
7990 converted.</p>
7991
7992<h5>Semantics:</h5>
7993<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7994 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7995 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7996 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7997
7998<h5>Examples:</h5>
7999<pre>
8000 %res = call i16 @llvm.convert.to.fp16(f32 %a)
8001 store i16 %res, i16* @x, align 2
8002</pre>
8003
8004</div>
8005
8006<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8007<h4>
8008 <a name="int_convert_from_fp16">
8009 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
8010 </a>
8011</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]8012
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8013<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]8014
8015<h5>Syntax:</h5>
8016<pre>
8017 declare f32 @llvm.convert.from.fp16(i16 %a)
8018</pre>
8019
8020<h5>Overview:</h5>
8021<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
8022 a conversion from half precision floating point format to single precision
8023 floating point format.</p>
8024
8025<h5>Arguments:</h5>
8026<p>The intrinsic function contains single argument - the value to be
8027 converted.</p>
8028
8029<h5>Semantics:</h5>
8030<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]8031 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]8032 precision floating point format. The input half-float value is represented by
8033 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]8034
8035<h5>Examples:</h5>
8036<pre>
8037 %a = load i16* @x, align 2
8038 %res = call f32 @llvm.convert.from.fp16(i16 %a)
8039</pre>
8040
8041</div>
8042
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8043</div>
8044
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]8045<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8046<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]8047 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8048</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]8049
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8050<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]8051
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8052<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
8053 prefix), are described in
8054 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
8055 Level Debugging</a> document.</p>
8056
8057</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]8058
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8059<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8060<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8061 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8062</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8063
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8064<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8065
8066<p>The LLVM exception handling intrinsics (which all start with
8067 <tt>llvm.eh.</tt> prefix), are described in
8068 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
8069 Handling</a> document.</p>
8070
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8071</div>
8072
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8073<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8074<h3>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]8075 <a name="int_trampoline">Trampoline Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8076</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8077
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8078<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8079
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]8080<p>These intrinsics make it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]8081 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
8082 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8083 function pointer lacking the nest parameter - the caller does not need to
8084 provide a value for it. Instead, the value to use is stored in advance in a
8085 "trampoline", a block of memory usually allocated on the stack, which also
8086 contains code to splice the nest value into the argument list. This is used
8087 to implement the GCC nested function address extension.</p>
8088
8089<p>For example, if the function is
8090 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
8091 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
8092 follows:</p>
8093
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]8094<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]8095 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
8096 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]8097 call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8*, i32, i32)* @f to i8*), i8* %nval)
8098 %p = call i8* @llvm.adjust.trampoline(i8* %tramp1)
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]8099 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8100</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8101
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8102<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
8103 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8104
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8105<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8106<h4>
8107 <a name="int_it">
8108 '<tt>llvm.init.trampoline</tt>' Intrinsic
8109 </a>
8110</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8111
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8112<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8113
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8114<h5>Syntax:</h5>
8115<pre>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]8116 declare void @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]8117</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8118
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8119<h5>Overview:</h5>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]8120<p>This fills the memory pointed to by <tt>tramp</tt> with executable code,
8121 turning it into a trampoline.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8122
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8123<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8124<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
8125 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
8126 sufficiently aligned block of memory; this memory is written to by the
8127 intrinsic. Note that the size and the alignment are target-specific - LLVM
8128 currently provides no portable way of determining them, so a front-end that
8129 generates this intrinsic needs to have some target-specific knowledge.
8130 The <tt>func</tt> argument must hold a function bitcast to
8131 an <tt>i8*</tt>.</p>
8132
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8133<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8134<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]8135 dependent code, turning it into a function. Then <tt>tramp</tt> needs to be
8136 passed to <a href="#int_at">llvm.adjust.trampoline</a> to get a pointer
8137 which can be <a href="#int_trampoline">bitcast (to a new function) and
8138 called</a>. The new function's signature is the same as that of
8139 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
8140 removed. At most one such <tt>nest</tt> argument is allowed, and it must be of
8141 pointer type. Calling the new function is equivalent to calling <tt>func</tt>
8142 with the same argument list, but with <tt>nval</tt> used for the missing
8143 <tt>nest</tt> argument. If, after calling <tt>llvm.init.trampoline</tt>, the
8144 memory pointed to by <tt>tramp</tt> is modified, then the effect of any later call
8145 to the returned function pointer is undefined.</p>
8146</div>
8147
8148<!-- _______________________________________________________________________ -->
8149<h4>
8150 <a name="int_at">
8151 '<tt>llvm.adjust.trampoline</tt>' Intrinsic
8152 </a>
8153</h4>
8154
8155<div>
8156
8157<h5>Syntax:</h5>
8158<pre>
8159 declare i8* @llvm.adjust.trampoline(i8* &lt;tramp&gt;)
8160</pre>
8161
8162<h5>Overview:</h5>
8163<p>This performs any required machine-specific adjustment to the address of a
8164 trampoline (passed as <tt>tramp</tt>).</p>
8165
8166<h5>Arguments:</h5>
8167<p><tt>tramp</tt> must point to a block of memory which already has trampoline code
8168 filled in by a previous call to <a href="#int_it"><tt>llvm.init.trampoline</tt>
8169 </a>.</p>
8170
8171<h5>Semantics:</h5>
8172<p>On some architectures the address of the code to be executed needs to be
8173 different to the address where the trampoline is actually stored. This
8174 intrinsic returns the executable address corresponding to <tt>tramp</tt>
8175 after performing the required machine specific adjustments.
8176 The pointer returned can then be <a href="#int_trampoline"> bitcast and
8177 executed</a>.
8178</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8179
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8180</div>
8181
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8182</div>
8183
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]8184<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8185<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8186 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8187</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8188
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8189<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8190
8191<p>This class of intrinsics exists to information about the lifetime of memory
8192 objects and ranges where variables are immutable.</p>
8193
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8194<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8195<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8196 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8197</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8198
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8199<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8200
8201<h5>Syntax:</h5>
8202<pre>
8203 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8204</pre>
8205
8206<h5>Overview:</h5>
8207<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8208 object's lifetime.</p>
8209
8210<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8211<p>The first argument is a constant integer representing the size of the
8212 object, or -1 if it is variable sized. The second argument is a pointer to
8213 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8214
8215<h5>Semantics:</h5>
8216<p>This intrinsic indicates that before this point in the code, the value of the
8217 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]8218 never be used and has an undefined value. A load from the pointer that
8219 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8220 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8221
8222</div>
8223
8224<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8225<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8226 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8227</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8228
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8229<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8230
8231<h5>Syntax:</h5>
8232<pre>
8233 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8234</pre>
8235
8236<h5>Overview:</h5>
8237<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8238 object's lifetime.</p>
8239
8240<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8241<p>The first argument is a constant integer representing the size of the
8242 object, or -1 if it is variable sized. The second argument is a pointer to
8243 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8244
8245<h5>Semantics:</h5>
8246<p>This intrinsic indicates that after this point in the code, the value of the
8247 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8248 never be used and has an undefined value. Any stores into the memory object
8249 following this intrinsic may be removed as dead.
8250
8251</div>
8252
8253<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8254<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8255 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8256</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8257
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8258<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8259
8260<h5>Syntax:</h5>
8261<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]8262 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8263</pre>
8264
8265<h5>Overview:</h5>
8266<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8267 a memory object will not change.</p>
8268
8269<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8270<p>The first argument is a constant integer representing the size of the
8271 object, or -1 if it is variable sized. The second argument is a pointer to
8272 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8273
8274<h5>Semantics:</h5>
8275<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8276 the return value, the referenced memory location is constant and
8277 unchanging.</p>
8278
8279</div>
8280
8281<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8282<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8283 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8284</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8285
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8286<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8287
8288<h5>Syntax:</h5>
8289<pre>
8290 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8291</pre>
8292
8293<h5>Overview:</h5>
8294<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8295 a memory object are mutable.</p>
8296
8297<h5>Arguments:</h5>
8298<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8299 The second argument is a constant integer representing the size of the
8300 object, or -1 if it is variable sized and the third argument is a pointer
8301 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8302
8303<h5>Semantics:</h5>
8304<p>This intrinsic indicates that the memory is mutable again.</p>
8305
8306</div>
8307
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8308</div>
8309
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8310<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8311<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8312 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8313</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8314
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8315<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8316
8317<p>This class of intrinsics is designed to be generic and has no specific
8318 purpose.</p>
8319
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8320<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8321<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8322 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8323</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8324
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8325<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8326
8327<h5>Syntax:</h5>
8328<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8329 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]8330</pre>
8331
8332<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8333<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8334
8335<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8336<p>The first argument is a pointer to a value, the second is a pointer to a
8337 global string, the third is a pointer to a global string which is the source
8338 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8339
8340<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8341<p>This intrinsic allows annotation of local variables with arbitrary strings.
8342 This can be useful for special purpose optimizations that want to look for
John Criswelle865c032011-08-19 16:57:55 +0000[diff] [blame]8343 these annotations. These have no other defined use; they are ignored by code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8344 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8345
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8346</div>
8347
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8348<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8349<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]8350 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8351</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8352
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8353<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8354
8355<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8356<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8357 any integer bit width.</p>
8358
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8359<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8360 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8361 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8362 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8363 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8364 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]8365</pre>
8366
8367<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8368<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8369
8370<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8371<p>The first argument is an integer value (result of some expression), the
8372 second is a pointer to a global string, the third is a pointer to a global
8373 string which is the source file name, and the last argument is the line
8374 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8375
8376<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8377<p>This intrinsic allows annotations to be put on arbitrary expressions with
8378 arbitrary strings. This can be useful for special purpose optimizations that
John Criswelle865c032011-08-19 16:57:55 +0000[diff] [blame]8379 want to look for these annotations. These have no other defined use; they
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8380 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8381
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8382</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8383
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8384<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8385<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8386 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8387</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8388
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8389<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8390
8391<h5>Syntax:</h5>
8392<pre>
Chris Lattner86208902012-05-27 23:20:41 +0000[diff] [blame]8393 declare void @llvm.trap() noreturn nounwind
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8394</pre>
8395
8396<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8397<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8398
8399<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8400<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8401
8402<h5>Semantics:</h5>
John Criswell99534f32012-05-16 00:26:51 +0000[diff] [blame]8403<p>This intrinsic is lowered to the target dependent trap instruction. If the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8404 target does not have a trap instruction, this intrinsic will be lowered to
John Criswell99534f32012-05-16 00:26:51 +0000[diff] [blame]8405 a call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8406
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8407</div>
8408
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8409<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8410<h4>
Dan Gohmana6063c62012-05-14 18:58:10 +0000[diff] [blame]8411 <a name="int_debugtrap">'<tt>llvm.debugtrap</tt>' Intrinsic</a>
Dan Gohmand4347e12012-05-11 00:19:32 +0000[diff] [blame]8412</h4>
8413
8414<div>
8415
8416<h5>Syntax:</h5>
8417<pre>
Chris Lattner86208902012-05-27 23:20:41 +0000[diff] [blame]8418 declare void @llvm.debugtrap() nounwind
Dan Gohmand4347e12012-05-11 00:19:32 +0000[diff] [blame]8419</pre>
8420
8421<h5>Overview:</h5>
Dan Gohmana6063c62012-05-14 18:58:10 +0000[diff] [blame]8422<p>The '<tt>llvm.debugtrap</tt>' intrinsic.</p>
Dan Gohmand4347e12012-05-11 00:19:32 +0000[diff] [blame]8423
8424<h5>Arguments:</h5>
8425<p>None.</p>
8426
8427<h5>Semantics:</h5>
8428<p>This intrinsic is lowered to code which is intended to cause an execution
8429 trap with the intention of requesting the attention of a debugger.</p>
8430
8431</div>
8432
8433<!-- _______________________________________________________________________ -->
8434<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8435 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8436</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8437
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8438<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8439
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8440<h5>Syntax:</h5>
8441<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8442 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8443</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8444
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8445<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8446<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8447 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8448 ensure that it is placed on the stack before local variables.</p>
8449
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8450<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8451<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8452 arguments. The first argument is the value loaded from the stack
8453 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8454 that has enough space to hold the value of the guard.</p>
8455
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8456<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8457<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8458 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8459 stack. This is to ensure that if a local variable on the stack is
8460 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8461 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8462 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8463 function.</p>
8464
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8465</div>
8466
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8467<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8468<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8469 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8470</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8471
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8472<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8473
8474<h5>Syntax:</h5>
8475<pre>
Nuno Lopes23e75da2012-05-22 15:25:31 +0000[diff] [blame]8476 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;min&gt;)
8477 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;min&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8478</pre>
8479
8480<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8481<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8482 the optimizers to determine at compile time whether a) an operation (like
8483 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8484 runtime check for overflow isn't necessary. An object in this context means
8485 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8486
8487<h5>Arguments:</h5>
Nuno Lopes23e75da2012-05-22 15:25:31 +0000[diff] [blame]8488<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8489 argument is a pointer to or into the <tt>object</tt>. The second argument
Nuno Lopes23e75da2012-05-22 15:25:31 +0000[diff] [blame]8490 is a boolean and determines whether <tt>llvm.objectsize</tt> returns 0 (if
8491 true) or -1 (if false) when the object size is unknown.
8492 The second argument only accepts constants.</p>
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8493
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8494<h5>Semantics:</h5>
Nuno Lopes30759542012-05-09 15:52:43 +0000[diff] [blame]8495<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to a constant representing
8496 the size of the object concerned. If the size cannot be determined at compile
Nuno Lopes23e75da2012-05-22 15:25:31 +0000[diff] [blame]8497 time, <tt>llvm.objectsize</tt> returns <tt>i32/i64 -1 or 0</tt>
8498 (depending on the <tt>min</tt> argument).</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8499
8500</div>
Jakub Staszakb170e2d2011-12-04 18:29:26 +0000[diff] [blame]8501<!-- _______________________________________________________________________ -->
8502<h4>
8503 <a name="int_expect">'<tt>llvm.expect</tt>' Intrinsic</a>
8504</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8505
Jakub Staszakb170e2d2011-12-04 18:29:26 +0000[diff] [blame]8506<div>
8507
8508<h5>Syntax:</h5>
8509<pre>
8510 declare i32 @llvm.expect.i32(i32 &lt;val&gt;, i32 &lt;expected_val&gt;)
8511 declare i64 @llvm.expect.i64(i64 &lt;val&gt;, i64 &lt;expected_val&gt;)
8512</pre>
8513
8514<h5>Overview:</h5>
8515<p>The <tt>llvm.expect</tt> intrinsic provides information about expected (the
8516 most probable) value of <tt>val</tt>, which can be used by optimizers.</p>
8517
8518<h5>Arguments:</h5>
8519<p>The <tt>llvm.expect</tt> intrinsic takes two arguments. The first
8520 argument is a value. The second argument is an expected value, this needs to
8521 be a constant value, variables are not allowed.</p>
8522
8523<h5>Semantics:</h5>
8524<p>This intrinsic is lowered to the <tt>val</tt>.</p>
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8525</div>
8526
8527</div>
8528
Jakub Staszakb170e2d2011-12-04 18:29:26 +0000[diff] [blame]8529</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8530<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8531<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8532<address>
8533 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8534 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8535 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8536 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]8537
8538 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8539 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8540 Last modified: $Date$
8541</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8542
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8543</body>
8544</html>