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gerrit-public.fairphone.software / toolchain / llvm-project / dfab443ae83958b5a6f0e052e6afbf4ae6d92999 / . / llvm / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Daniel Dunbar46d611a2012-04-19 20:20:34 +0000[diff] [blame]10 <link rel="stylesheet" href="_static/llvm.css" type="text/css">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling578ee402010-08-20 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 Wendling8693ef82009-07-20 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 Lattner80d73c72009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
Bill Wendlingb4d076e2011-10-11 06:41:28 +0000[diff] [blame]38 <li><a href="#linkage_external">'<tt>external</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 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 Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]56 <li><a href="#memmodel">Memory Model for Concurrent Operations</a></li>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]57 <li><a href="#ordering">Atomic Memory Ordering Constraints</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]58 </ol>
59 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]60 <li><a href="#typesystem">Type System</a>
61 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]63 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]64 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]65 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]67 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner7824d182008-01-04 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 Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]70 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#t_derived">Derived Types</a>
74 <ol>
Chris Lattner392be582010-02-12 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 Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]79 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]80 <li><a href="#t_vector">Vector Type</a></li>
81 </ol>
82 </li>
Misha Brukman76307852003-11-08 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 Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
87 </ol>
88 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 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 Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]95 <li><a href="#poisonvalues">Poison Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Peter Collingbourneec9ff672011-10-27 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 Sands34bd91a2012-04-14 12:36:06 +0000[diff] [blame]106 <li><a href="#fpmath">'<tt>fpmath</tt>' Metadata</a></li>
Rafael Espindolaef9f5502012-03-24 00:14:51 +0000[diff] [blame]107 <li><a href="#range">'<tt>range</tt>' Metadata</a></li>
Peter Collingbourneec9ff672011-10-27 19:19:07 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]110 </ol>
111 </li>
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]112 <li><a href="#module_flags">Module Flags Metadata</a>
113 <ol>
Bill Wendling73462772012-02-16 01:10:50 +0000[diff] [blame]114 <li><a href="#objc_gc_flags">Objective-C Garbage Collection Module Flags Metadata</a></li>
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]115 </ol>
116 </li>
Chris Lattnerae76db52009-07-20 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 Lattner58f9bb22009-07-20 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 Lattnerae76db52009-07-20 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 Lattner2f7c9632001-06-06 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 Lattner48b383b02003-11-25 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 Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]134 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]135 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]136 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]137 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]138 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]139 </ol>
140 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]141 <li><a href="#binaryops">Binary Operations</a>
142 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]143 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]144 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]145 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]146 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]147 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]148 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 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 Spencer7eb55b32006-11-02 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 Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]157 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
158 <ol>
Reid Spencer2ab01932007-02-02 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 Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]162 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]163 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]164 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]165 </ol>
166 </li>
Chris Lattnerce83bff2006-04-08 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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]172 </ol>
173 </li>
Dan Gohmanb9d66602008-05-12 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 Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]180 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]181 <ol>
Eli Friedmanc9a551e2011-07-28 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 Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]188 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]189 </ol>
190 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]191 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 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 Spencer51b07252006-11-09 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 Spencerb7344ff2006-11-11 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 Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]204 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]205 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]206 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]207 <li><a href="#otherops">Other Operations</a>
208 <ol>
Reid Spencerc828a0e2006-11-18 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 Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]211 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]212 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]213 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]214 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]215 <li><a href="#i_landingpad">'<tt>landingpad</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]216 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]217 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]218 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]219 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]220 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]221 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]222 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
223 <ol>
Reid Spencer96a5f022007-04-04 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 Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]227 </ol>
228 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]229 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
230 <ol>
Reid Spencer96a5f022007-04-04 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 Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]234 </ol>
235 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]236 <li><a href="#int_codegen">Code Generator Intrinsics</a>
237 <ol>
Reid Spencer96a5f022007-04-04 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 Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]244 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]245 </ol>
246 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]247 <li><a href="#int_libc">Standard C Library Intrinsics</a>
248 <ol>
Reid Spencer96a5f022007-04-04 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 Gohmanb6324c12007-10-15 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 Gohmane635c522011-05-27 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 Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]259 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]260 </ol>
261 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]262 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]263 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]264 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 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 Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]268 </ol>
269 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]270 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
271 <ol>
Bill Wendlingfd2bd722009-02-08 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 Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]277 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]278 </ol>
279 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]280 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
281 <ol>
Chris Lattnerbbd8bd32010-03-14 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 Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]284 </ol>
285 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]286 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]287 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsa0984362011-09-06 13:37:06 +0000[diff] [blame]288 <li><a href="#int_trampoline">Trampoline Intrinsics</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]289 <ol>
290 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sandsa0984362011-09-06 13:37:06 +0000[diff] [blame]291 <li><a href="#int_at">'<tt>llvm.adjust.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]292 </ol>
293 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]294 <li><a href="#int_memorymarkers">Memory Use Markers</a>
295 <ol>
Jakub Staszak5fd147f2011-12-04 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 Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]300 </ol>
301 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]302 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]303 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]304 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]306 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]307 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]308 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.trap</tt>' Intrinsic</a></li>
Dan Gohmandfab4432012-05-11 00:19:32 +0000[diff] [blame^]310 <li><a href="#int_debugger">
311 '<tt>llvm.debugger</tt>' Intrinsic</a></li>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]312 <li><a href="#int_stackprotector">
313 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]314 <li><a href="#int_objectsize">
315 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Jakub Staszak5fef7922011-12-04 18:29:26 +0000[diff] [blame]316 <li><a href="#int_expect">
317 '<tt>llvm.expect</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]318 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]319 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]320 </ol>
321 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]322</ol>
Chris Lattner757528b0b2004-05-23 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 Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]327</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]328
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]329<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]330<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]331<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]332
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]333<div>
Bill Wendlingd9a66f72009-07-20 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 Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]341</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]342
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]343<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]344<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]345<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]346
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]347<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]348
Bill Wendlingd9a66f72009-07-20 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 Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]357
Bill Wendlingd9a66f72009-07-20 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 Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]365 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]366 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]367
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]368<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]369<h4>
370 <a name="wellformed">Well-Formedness</a>
371</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]372
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]373<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]374
Bill Wendlingd9a66f72009-07-20 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 Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]379
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]380<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]381%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]382</pre>
383
Bill Wendling7f4a3362009-11-02 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]390
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]391</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]392
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]393</div>
394
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]395<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]396
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]397<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]398<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]399<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]400
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]401<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]402
Bill Wendlingd9a66f72009-07-20 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 Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]408
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]409<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]410 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]418
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]419 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]420 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]422 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]423 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]424</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]425
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]426<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]431
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]432<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]441
442<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]443 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]445<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]447<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]448%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]449</pre>
450
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]451<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]452
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]453<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]454%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]455</pre>
456
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]457<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]458
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]459<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 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 Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]462%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]463</pre>
464
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]468<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]469 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]470 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]471
472 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]473 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]474
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]475 <li>Unnamed temporaries are numbered sequentially</li>
476</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]477
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]478<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]482
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]483</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]484
485<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]486<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]487<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]488<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]490<h3>
491 <a name="modulestructure">Module Structure</a>
492</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]493
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]494<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]495
Bill Wendling21ee0d22012-03-14 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]503<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]504<i>; Declare the string constant as a global constant.</i>&nbsp;
Bill Wendling21ee0d22012-03-14 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]506
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]507<i>; External declaration of the puts function</i>&nbsp;
Bill Wendling21ee0d22012-03-14 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]509
510<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]511define i32 @main() { <i>; i32()* </i>&nbsp;
512 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
Bill Wendling21ee0d22012-03-14 08:07:43 +0000[diff] [blame]513 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.str, i64 0, i64 0
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]514
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]515 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
Bill Wendling21ee0d22012-03-14 08:07:43 +0000[diff] [blame]516 <a href="#i_call">call</a> i32 @puts(i8* %cast210)
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]517 <a href="#i_ret">ret</a> i32 0&nbsp;
518}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]519
520<i>; Named metadata</i>
Bill Wendling21ee0d22012-03-14 08:07:43 +0000[diff] [blame]521!1 = metadata !{i32 42}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]522!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]523</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]524
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]525<p>This example is made up of a <a href="#globalvars">global variable</a> named
Bill Wendling21ee0d22012-03-14 08:07:43 +0000[diff] [blame]526 "<tt>.str</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]527 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]528 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
Bill Wendling21ee0d22012-03-14 08:07:43 +0000[diff] [blame]529 "<tt>foo</tt>".</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]530
Bill Wendling21ee0d22012-03-14 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 Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]536
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]537</div>
538
539<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]540<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]541 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]542</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]543
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]544<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]545
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]546<p>All Global Variables and Functions have one of the following types of
547 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]548
549<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]550 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 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 Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]557
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]558 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 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 Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]569
Bill Wendling578ee402010-08-20 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 Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]579 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]580 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]583
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]584 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]585 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 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 Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]592
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]593 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]594 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]606
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]607 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 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 Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]613 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 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 Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]619 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]620 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]621 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
622 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]623
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]624
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]625 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]626 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 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 Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]631
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]632 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]636
Bill Wendling7f4a3362009-11-02 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 Wendlingd9a66f72009-07-20 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 Wendling03bcd6e2010-07-01 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 Wendlingd9a66f72009-07-20 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 Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]646
Bill Wendlingef3cdea2011-11-04 20:40:41 +0000[diff] [blame]647 <dt><tt><b><a name="linkage_external">external</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]648 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 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 Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]651</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlingd9a66f72009-07-20 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 Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]656
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]657<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]658 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]659 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 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 Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]664
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]665 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]666 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]671</dl>
672
Bill Wendlingd9a66f72009-07-20 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 Wendlingb4d076e2011-10-11 06:41:28 +0000[diff] [blame]680 other than <tt>external</tt>, <tt>dllimport</tt>
681 or <tt>extern_weak</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]682
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]683<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]684 or <tt>weak_odr</tt> linkages.</p>
685
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]686</div>
687
688<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]689<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]690 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]691</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]692
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]693<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]694
695<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 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 Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]701
702<dl>
703 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]704 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 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 Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]709
710 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]711 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 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 Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]715 (Application Binary Interface).
716 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 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 Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]720
721 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]722 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 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 Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]728
Chris Lattnera179e4d2010-03-11 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 Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]749 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]750 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]751 target-specific calling conventions to be used. Target specific calling
752 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]753</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]754
755<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]756 support Pascal conventions or any other well-known target-independent
757 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]758
759</div>
760
761<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]762<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]764</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]765
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]766<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]767
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]768<p>All Global Variables and Functions have one of the following visibility
769 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]770
771<dl>
772 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]773 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 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 Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]778
779 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]780 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 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 Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]785
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]786 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]787 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 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 Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]791</dl>
792
793</div>
794
795<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]796<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]797 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]798</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]799
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]800<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]801
802<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 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 Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]805
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]806<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]807%mytype = type { %mytype*, i32 }
808</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]809
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]810<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]811 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]812 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]813
814<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 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 Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]823
824</div>
825
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]826<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]827<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]828 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]829</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]830
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]831<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]832
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]833<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 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 Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]844
Bill Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]851
Bill Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]857
Rafael Espindola45e6c192011-01-08 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 Espindolaf1ed7812011-01-15 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 Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]864
Bill Wendlingd9a66f72009-07-20 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 Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]870
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]871<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]872 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]873
Chris Lattner78e00bc2010-04-28 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 Lattner4bd85e42010-04-28 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 Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]883
Bill Wendlingd9a66f72009-07-20 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 Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]886
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]887<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]888@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]889</pre>
890
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]891</div>
892
893
894<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]895<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]896 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]897</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]898
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]899<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]900
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]901<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 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 Espindola45e6c192011-01-08 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 Wendlingd9a66f72009-07-20 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 Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]912
Bill Wendlingd9a66f72009-07-20 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 Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]915 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 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 Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]921
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]922<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]927
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]928<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]933
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]934<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]935 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]936
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]937<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 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 Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]942
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]943<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
Bill Wendlingef3cdea2011-11-04 20:40:41 +0000[diff] [blame]944 be significant and two identical functions can be merged.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]945
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]946<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]947<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]948define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 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 Patel02256232008-10-07 17:48:33 +0000[diff] [blame]954
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]955</div>
956
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]957<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]958<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]959 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]960</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]961
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]962<div>
Bill Wendlingd9a66f72009-07-20 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 Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]968
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]969<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]970<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]971@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]972</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]973
974</div>
975
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]976<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]977<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]978 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]979</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]980
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]981<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]982
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]983<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]984 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]985 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]986
987<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]988<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]989; Some unnamed metadata nodes, which are referenced by the named metadata.
990!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]991!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]992!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]993; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]994!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]995</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]996
997</div>
998
999<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1000<h3>
1001 <a name="paramattrs">Parameter Attributes</a>
1002</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1003
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1004<div>
Bill Wendlingd9a66f72009-07-20 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 Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1016
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1017<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1018declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1019declare i32 @atoi(i8 zeroext)
1020declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1021</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1022
Bill Wendlingd9a66f72009-07-20 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 Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1025
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1026<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1027
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1028<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1029 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1030 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 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 Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1034
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1035 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1036 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 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 Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1040
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1041 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1047
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1048 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1052 is made between the caller and the callee, so the callee is unable to
1053 modify the value in the callee. This attribute is only valid on LLVM
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 Lattnerd78dbee2010-11-20 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1066
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1067 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1075 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 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 Gohmande256292010-07-02 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 Gohmandf12d082010-07-02 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 Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1087 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1088<br>
John McCall72ed8902010-07-06 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 Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1091 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1096
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1097 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1102 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1107
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1108</div>
1109
1110<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1111<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1112 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1113</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1114
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1115<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1116
Bill Wendlingd9a66f72009-07-20 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 Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1120<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1121define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1122</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1123
1124<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 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 Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1128</div>
1129
1130<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1131<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1132 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1133</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1134
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1135<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendlingd9a66f72009-07-20 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 Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1141
Bill Wendlingd9a66f72009-07-20 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 Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1144
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1145<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1146define void @f() noinline { ... }
1147define void @f() alwaysinline { ... }
1148define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1149define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1150</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1151
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1152<dl>
Kostya Serebryanya5054ad2012-01-20 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 Davisbe5557e2010-02-12 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 Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1162 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1166
Dan Gohman8bd11f12011-06-16 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 Olesen74bb06c2010-02-06 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 Lewycky14b58da2010-07-06 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 Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1184 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1188
Nick Lewycky14b58da2010-07-06 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 Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1192
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1193 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1197
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1202
Nick Lewycky14b58da2010-07-06 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 Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1208 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Wendling3f6a3a22012-02-06 21:57:33 +0000[diff] [blame]1216 exceptions by calling the <tt>C++</tt> exception throwing methods.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1217
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1218 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Wendling3f6a3a22012-02-06 21:57:33 +0000[diff] [blame]1226 exception by calling the <tt>C++</tt> exception throwing methods.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1227
Bill Wendlingb437ab82011-12-05 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 Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1234 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1245 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 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 Wendling30235112009-07-20 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 Espindola163d6752011-07-25 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 Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1261</dl>
1262
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1263</div>
1264
1265<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1266<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1267 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1268</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1269
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1270<div>
Bill Wendlingd9a66f72009-07-20 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 Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1276
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1277<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1278module asm "inline asm code goes here"
1279module asm "more can go here"
1280</pre>
Chris Lattner91c15c42006-01-23 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1284 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1285
Bill Wendlingd9a66f72009-07-20 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 Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1289</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1290
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1291<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1292<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1293 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1294</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1295
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1296<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1297
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1298<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 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 Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1302<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1303target datalayout = "<i>layout specification</i>"
1304</pre>
Bill Wendlingd9a66f72009-07-20 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 Spencer50c723a2007-02-19 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1314 bits with the most significance have the lowest address location.</dd>
1315
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1316 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1317 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1318 the bits with the least significance have the lowest address
1319 location.</dd>
1320
Lang Hamesde7ab802011-10-10 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 Hamesff2c52c2011-10-11 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 Hamesde7ab802011-10-10 23:42:08 +0000[diff] [blame]1327
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1328 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1329 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingd9a66f72009-07-20 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 Spencer50c723a2007-02-19 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 Wendlingd9a66f72009-07-20 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 Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1338 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1339 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1340 <i>size</i>.</dd>
1341
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1342 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1343 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1348
Reid Spencer50c723a2007-02-19 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1351 <i>size</i>.</dd>
1352
Daniel Dunbar7921a592009-06-08 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1355 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 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 Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1361 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1362 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1363</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1364
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1365<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1366 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 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 Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1370<ul>
1371 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1372 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencer50c723a2007-02-19 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 Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1377 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 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 Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1384 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1385</ul>
Bill Wendlingd9a66f72009-07-20 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 Spencer50c723a2007-02-19 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1392 specification is used.</li>
1393
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1394 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlingd9a66f72009-07-20 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 Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1402 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlingd9a66f72009-07-20 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 Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1406</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1407
Chris Lattner48797402011-10-11 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 Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1424</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1425
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1426<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1427<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1428 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1429</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1430
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1431<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1432
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1433<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1434with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 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 Gohmandf12d082010-07-02 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 Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1441 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 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 Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1446 no address.</li>
Dan Gohman6154a012009-07-27 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 Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1450 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1451 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 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 Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1474
1475<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 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 Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1478interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 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 Gohman6154a012009-07-27 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 Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1490<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1491<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1492 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1493</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1494
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1495<div>
Jeffrey Yasskin5d284ae2010-04-26 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 Friedman35b54aa2011-07-20 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 Friedman95f69a42011-08-22 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 Friedman35b54aa2011-07-20 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 Friedmanc9a551e2011-07-28 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 Friedman35b54aa2011-07-20 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 Friedmanf12e4e92011-07-22 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 Friedman35b54aa2011-07-20 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 Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1551 does not see <var>write<sub>1</sub></var>.
Bill Wendling537603b2011-07-31 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 Friedman35b54aa2011-07-20 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 Friedman95f69a42011-08-22 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 Friedman35b54aa2011-07-20 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 Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1567 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1568 <var>R<sub>byte</sub></var> returns the value written by that
1569 write.</li>
Eli Friedmanf12e4e92011-07-22 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 Friedmanc9a551e2011-07-28 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 Friedman35b54aa2011-07-20 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 Friedman4bc9f3c2011-08-02 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 Friedman35b54aa2011-07-20 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 Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1606<!-- ======================================================================= -->
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]1607<h3>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1608 <a name="ordering">Atomic Memory Ordering Constraints</a>
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]1609</h3>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1610
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]1611<div>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1612
1613<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
Eli Friedman59b66882011-08-09 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 Friedman75362532011-08-09 23:26:12 +0000[diff] [blame]1617<a href="#i_store"><code>atomic store</code></a>) take an ordering parameter
Eli Friedmanc9a551e2011-07-28 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 Friedman95f69a42011-08-22 21:35:27 +0000[diff] [blame]1621check those specs (see spec references in the
Nick Lewycky75499f52012-01-23 08:47:21 +0000[diff] [blame]1622<a href="Atomics.html#introduction">atomics guide</a>).
Eli Friedman95f69a42011-08-22 21:35:27 +0000[diff] [blame]1623<a href="#i_fence"><code>fence</code></a> instructions
Eli Friedmanc9a551e2011-07-28 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 Friedman95f69a42011-08-22 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 Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1630<dl>
Eli Friedmanc9a551e2011-07-28 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 Friedman95f69a42011-08-22 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 Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1656<dt><code>acquire</code></dt>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1657<dd>In addition to the guarantees of <code>monotonic</code>,
Eli Friedman0cb3b562011-08-24 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 Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1666<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
Eli Friedman95f69a42011-08-22 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 Friedmanc9a551e2011-07-28 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 Friedman95f69a42011-08-22 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 Friedmanc9a551e2011-07-28 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 Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1687</div>
1688
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1689<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1690<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1691<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1692
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1693<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1694
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1695<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1702
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1703<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1704<h3>
1705 <a name="t_classifications">Type Classifications</a>
1706</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1707
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1708<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1709
1710<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1711
1712<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1713 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1714 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1715 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1716 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1717 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1718 </tr>
1719 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1720 <td><a href="#t_floating">floating point</a></td>
Dan Gohman518cda42011-12-17 00:04:22 +0000[diff] [blame]1721 <td><tt>half, float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1722 </tr>
1723 <tr>
1724 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 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 Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1728 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1729 <a href="#t_struct">structure</a>,
1730 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1731 <a href="#t_label">label</a>,
1732 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1733 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1734 </tr>
Chris Lattner7824d182008-01-04 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 Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1739 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1740 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1741 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1742 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1743 </tr>
1744 <tr>
1745 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1746 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 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 Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1750 <a href="#t_vector">vector</a>,
1751 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1752 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1753 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1754 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1755</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1756
Bill Wendlingd9a66f72009-07-20 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 Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1759 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1760
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1761</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1762
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1763<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1764<h3>
1765 <a name="t_primitive">Primitive Types</a>
1766</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1767
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1768<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1769
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1770<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1771 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1772
1773<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1774<h4>
1775 <a name="t_integer">Integer Type</a>
1776</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1777
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1778<div>
Nick Lewycky84a1eeb2009-09-27 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 Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1809</div>
1810
1811<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1812<h4>
1813 <a name="t_floating">Floating Point Types</a>
1814</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1815
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1816<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1817
1818<table>
1819 <tbody>
1820 <tr><th>Type</th><th>Description</th></tr>
Dan Gohman518cda42011-12-17 00:04:22 +0000[diff] [blame]1821 <tr><td><tt>half</tt></td><td>16-bit floating point value</td></tr>
Bill Wendlingd9a66f72009-07-20 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 Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1830</div>
1831
1832<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1833<h4>
1834 <a name="t_x86mmx">X86mmx Type</a>
1835</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1836
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1837<div>
Dale Johannesen33e5c352010-10-01 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 Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1844 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1845</pre>
1846
1847</div>
1848
1849<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1850<h4>
1851 <a name="t_void">Void Type</a>
1852</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1853
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1854<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1855
Chris Lattner7824d182008-01-04 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 Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1860<pre>
1861 void
1862</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1863
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1864</div>
1865
1866<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1867<h4>
1868 <a name="t_label">Label Type</a>
1869</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1870
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1871<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1872
Chris Lattner7824d182008-01-04 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 Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1877<pre>
1878 label
1879</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1880
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1881</div>
1882
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1883<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1884<h4>
1885 <a name="t_metadata">Metadata Type</a>
1886</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1887
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1888<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1889
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1890<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 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 Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1894
1895<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1896<pre>
1897 metadata
1898</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1899
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1900</div>
1901
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1902</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1903
1904<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1905<h3>
1906 <a name="t_derived">Derived Types</a>
1907</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1908
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1909<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1910
Bill Wendlingd9a66f72009-07-20 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 Lewycky84a1eeb2009-09-27 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 Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1917
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1918<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1919<h4>
1920 <a name="t_aggregate">Aggregate Types</a>
1921</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1922
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1923<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1924
1925<p>Aggregate Types are a subset of derived types that can contain multiple
Duncan Sands9aaec152011-12-14 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 Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1929
1930</div>
1931
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1932<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1933<h4>
1934 <a name="t_array">Array Type</a>
1935</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1936
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1937<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1938
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1939<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1940<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 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 Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1943
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1944<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1945<pre>
1946 [&lt;# elements&gt; x &lt;elementtype&gt;]
1947</pre>
1948
Bill Wendlingd9a66f72009-07-20 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 Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1951
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1952<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1953<table class="layout">
1954 <tr class="layout">
Chris Lattner747359f2007-12-19 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 Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1965 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1966</table>
Reid Spencerc3c4c4f2004-11-01 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 Lattner747359f2007-12-19 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 Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1980 </tr>
1981</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1982
Dan Gohmanc74bc282009-11-09 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 Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1989
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1990</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1991
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1992<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1993<h4>
1994 <a name="t_function">Function Type</a>
1995</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1996
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1997<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1998
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1999<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 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 Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]2002 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]2003
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2004<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2005<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]2006 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2007</pre>
2008
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2009<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlingd9a66f72009-07-20 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 Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]2014 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]2015 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2016
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2017<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2018<table class="layout">
2019 <tr class="layout">
Reid Spencer58c08712006-12-31 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 Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2022 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]2023 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]2024 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]2025 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2026 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 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 Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]2029 </td>
2030 </tr><tr class="layout">
2031 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 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 Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]2035 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2036 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2037 </tr><tr class="layout">
2038 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 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 Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2041 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2042 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2043</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2044
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2045</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2046
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2047<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2048<h4>
2049 <a name="t_struct">Structure Type</a>
2050</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2051
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2052<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2053
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2054<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2055<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2056 in memory. The elements of a structure may be any type that has a size.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2057
Jeffrey Yasskinf991bbb2010-01-11 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 Lattnerb1ed91f2011-07-09 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 Lattner190552d2011-08-12 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 Lattner7bd0ea32011-10-11 23:02:17 +0000[diff] [blame]2069 what the underlying code generator expects.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2070
Chris Lattner190552d2011-08-12 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 Lattner32531732011-08-12 18:12:40 +0000[diff] [blame]2075 no way to write one. Identified types can be recursive, can be opaqued, and are
Chris Lattner190552d2011-08-12 17:31:02 +0000[diff] [blame]2076 never uniqued.
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2077</p>
2078
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2079<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2080<pre>
Chris Lattner190552d2011-08-12 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 Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2083</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2084
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2085<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2086<table class="layout">
2087 <tr class="layout">
Jeff Cohen5819f182007-04-22 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 Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2090 </tr>
2091 <tr class="layout">
Jeff Cohen5819f182007-04-22 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 Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2097 </tr>
Chris Lattnerb1ed91f2011-07-09 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 Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2102</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2103
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2104</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2105
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2106<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2107<h4>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2108 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2109</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2110
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2111<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2112
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2113<h5>Overview:</h5>
Chris Lattner2a843822011-07-23 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 Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2117
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2118<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2119<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2120 %X = type opaque
2121 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2122</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2123
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2124<h5>Examples:</h5>
2125<table class="layout">
2126 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2127 <td class="left"><tt>opaque</tt></td>
2128 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2129 </tr>
2130</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2131
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2132</div>
2133
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2134
2135
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2136<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2137<h4>
2138 <a name="t_pointer">Pointer Type</a>
2139</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2140
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2141<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2142
2143<h5>Overview:</h5>
Dan Gohman88481112010-02-25 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 Wendlingd9a66f72009-07-20 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 Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2154
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2155<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2156<pre>
2157 &lt;type&gt; *
2158</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2159
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2160<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2161<table class="layout">
2162 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2163 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 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 Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]2168 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2169 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2170 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 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 Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2177 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2178</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2179
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2180</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2181
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2182<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2183<h4>
2184 <a name="t_vector">Vector Type</a>
2185</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2186
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2187<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2188
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2189<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 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 Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]2193 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2194 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2195
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2196<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2197<pre>
2198 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2199</pre>
2200
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]2201<p>The number of elements is a constant integer value larger than 0; elementtype
Nadav Rotem3924cb02011-12-05 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 Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2204
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2205<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2206<table class="layout">
2207 <tr class="layout">
Chris Lattner747359f2007-12-19 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 Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2218 </tr>
Nadav Rotem3924cb02011-12-05 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 Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2223</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2224
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2225</div>
2226
Bill Wendlingae8b5ea2011-07-31 06:47:33 +0000[diff] [blame]2227</div>
2228
NAKAMURA Takumia35cdd62011-10-31 13:04:26 +0000[diff] [blame]2229</div>
2230
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2231<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2232<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2233<!-- *********************************************************************** -->
2234
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2235<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2236
2237<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2238 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2239
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2240<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2241<h3>
2242 <a name="simpleconstants">Simple Constants</a>
2243</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2244
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2245<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2246
2247<dl>
2248 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2249 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2250 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2251
2252 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 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 Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2256
2257 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2258 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 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 Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2264
2265 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2266 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2267 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2268</dl>
2269
Bill Wendlingd9a66f72009-07-20 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 Gohman518cda42011-12-17 00:04:22 +0000[diff] [blame]2281<p>When using the hexadecimal form, constants of types half, float, and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2282 represented using the 16-digit form shown above (which matches the IEEE754
Dan Gohman518cda42011-12-17 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 Wendlingd9a66f72009-07-20 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
2292 they match the long double format on your target. All hexadecimal formats
2293 are big-endian (sign bit at the left).</p>
2294
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2295<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2296</div>
2297
2298<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2299<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2300<a name="aggregateconstants"></a> <!-- old anchor -->
2301<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2302</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2303
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2304<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2305
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2306<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2307 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2308
2309<dl>
2310 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2311 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2312 type definitions (a comma separated list of elements, surrounded by braces
2313 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2314 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2315 Structure constants must have <a href="#t_struct">structure type</a>, and
2316 the number and types of elements must match those specified by the
2317 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2318
2319 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2320 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2321 definitions (a comma separated list of elements, surrounded by square
2322 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2323 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2324 the number and types of elements must match those specified by the
2325 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2326
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2327 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2328 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2329 definitions (a comma separated list of elements, surrounded by
2330 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2331 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2332 have <a href="#t_vector">vector type</a>, and the number and types of
2333 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2334
2335 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2336 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2337 value to zero of <em>any</em> type, including scalar and
2338 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2339 This is often used to avoid having to print large zero initializers
2340 (e.g. for large arrays) and is always exactly equivalent to using explicit
2341 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2342
2343 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2344 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2345 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2346 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2347 be interpreted as part of the instruction stream, metadata is a place to
2348 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2349</dl>
2350
2351</div>
2352
2353<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2354<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2355 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2356</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2357
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2358<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2359
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2360<p>The addresses of <a href="#globalvars">global variables</a>
2361 and <a href="#functionstructure">functions</a> are always implicitly valid
2362 (link-time) constants. These constants are explicitly referenced when
2363 the <a href="#identifiers">identifier for the global</a> is used and always
2364 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2365 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2366
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2367<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2368@X = global i32 17
2369@Y = global i32 42
2370@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2371</pre>
2372
2373</div>
2374
2375<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2376<h3>
2377 <a name="undefvalues">Undefined Values</a>
2378</h3>
2379
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2380<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2381
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2382<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2383 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2384 Undefined values may be of any type (other than '<tt>label</tt>'
2385 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2386
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2387<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2388 program is well defined no matter what value is used. This gives the
2389 compiler more freedom to optimize. Here are some examples of (potentially
2390 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2391
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2392
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2393<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2394 %A = add %X, undef
2395 %B = sub %X, undef
2396 %C = xor %X, undef
2397Safe:
2398 %A = undef
2399 %B = undef
2400 %C = undef
2401</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2402
2403<p>This is safe because all of the output bits are affected by the undef bits.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2404 Any output bit can have a zero or one depending on the input bits.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2405
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2406<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2407 %A = or %X, undef
2408 %B = and %X, undef
2409Safe:
2410 %A = -1
2411 %B = 0
2412Unsafe:
2413 %A = undef
2414 %B = undef
2415</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2416
2417<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2418 For example, if <tt>%X</tt> has a zero bit, then the output of the
2419 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2420 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2421 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2422 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2423 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2424 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2425 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2426
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2427<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2428 %A = select undef, %X, %Y
2429 %B = select undef, 42, %Y
2430 %C = select %X, %Y, undef
2431Safe:
2432 %A = %X (or %Y)
2433 %B = 42 (or %Y)
2434 %C = %Y
2435Unsafe:
2436 %A = undef
2437 %B = undef
2438 %C = undef
2439</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2440
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2441<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2442 branch) conditions can go <em>either way</em>, but they have to come from one
2443 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2444 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2445 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2446 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2447 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2448 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2449
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2450<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2451 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2452
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2453 %B = undef
2454 %C = xor %B, %B
2455
2456 %D = undef
2457 %E = icmp lt %D, 4
2458 %F = icmp gte %D, 4
2459
2460Safe:
2461 %A = undef
2462 %B = undef
2463 %C = undef
2464 %D = undef
2465 %E = undef
2466 %F = undef
2467</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2468
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2469<p>This example points out that two '<tt>undef</tt>' operands are not
2470 necessarily the same. This can be surprising to people (and also matches C
2471 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2472 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2473 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2474 its value over its "live range". This is true because the variable doesn't
2475 actually <em>have a live range</em>. Instead, the value is logically read
2476 from arbitrary registers that happen to be around when needed, so the value
2477 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2478 need to have the same semantics or the core LLVM "replace all uses with"
2479 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2480
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2481<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2482 %A = fdiv undef, %X
2483 %B = fdiv %X, undef
2484Safe:
2485 %A = undef
2486b: unreachable
2487</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2488
2489<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2490 value</em> and <em>undefined behavior</em>. An undefined value (like
2491 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2492 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2493 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2494 defined on SNaN's. However, in the second example, we can make a more
2495 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2496 arbitrary value, we are allowed to assume that it could be zero. Since a
2497 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2498 the operation does not execute at all. This allows us to delete the divide and
2499 all code after it. Because the undefined operation "can't happen", the
2500 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2501
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2502<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2503a: store undef -> %X
2504b: store %X -> undef
2505Safe:
2506a: &lt;deleted&gt;
2507b: unreachable
2508</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2509
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2510<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2511 undefined value can be assumed to not have any effect; we can assume that the
2512 value is overwritten with bits that happen to match what was already there.
2513 However, a store <em>to</em> an undefined location could clobber arbitrary
2514 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2515
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2516</div>
2517
2518<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2519<h3>
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]2520 <a name="poisonvalues">Poison Values</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2521</h3>
2522
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2523<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2524
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]2525<p>Poison values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohman32772f72011-12-06 03:35:58 +0000[diff] [blame]2526 they also represent the fact that an instruction or constant expression which
2527 cannot evoke side effects has nevertheless detected a condition which results
2528 in undefined behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2529
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]2530<p>There is currently no way of representing a poison value in the IR; they
Dan Gohmanac355aa2010-05-03 14:51:43 +0000[diff] [blame]2531 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2532 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag.</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2533
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]2534<p>Poison value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2535
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2536<ul>
2537<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2538 their operands.</li>
2539
2540<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2541 to their dynamic predecessor basic block.</li>
2542
2543<li>Function arguments depend on the corresponding actual argument values in
2544 the dynamic callers of their functions.</li>
2545
2546<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2547 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2548 control back to them.</li>
2549
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2550<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
Bill Wendling3f6a3a22012-02-06 21:57:33 +0000[diff] [blame]2551 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_resume"><tt>resume</tt></a>,
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2552 or exception-throwing call instructions that dynamically transfer control
2553 back to them.</li>
2554
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2555<li>Non-volatile loads and stores depend on the most recent stores to all of the
2556 referenced memory addresses, following the order in the IR
2557 (including loads and stores implied by intrinsics such as
2558 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2559
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2560<!-- TODO: In the case of multiple threads, this only applies if the store
2561 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2562
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2563<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2564
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2565<li>An instruction with externally visible side effects depends on the most
2566 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2567 the order in the IR. (This includes
2568 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2569
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2570<li>An instruction <i>control-depends</i> on a
2571 <a href="#terminators">terminator instruction</a>
2572 if the terminator instruction has multiple successors and the instruction
2573 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2574 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2575
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2576<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2577 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2578 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2579 successor.</li>
2580
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2581<li>Dependence is transitive.</li>
2582
2583</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2584
Dan Gohman32772f72011-12-06 03:35:58 +0000[diff] [blame]2585<p>Poison Values have the same behavior as <a href="#undefvalues">undef values</a>,
2586 with the additional affect that any instruction which has a <i>dependence</i>
2587 on a poison value has undefined behavior.</p>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2588
2589<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2590
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2591<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2592entry:
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]2593 %poison = sub nuw i32 0, 1 ; Results in a poison value.
Dan Gohman32772f72011-12-06 03:35:58 +0000[diff] [blame]2594 %still_poison = and i32 %poison, 0 ; 0, but also poison.
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]2595 %poison_yet_again = getelementptr i32* @h, i32 %still_poison
Dan Gohman32772f72011-12-06 03:35:58 +0000[diff] [blame]2596 store i32 0, i32* %poison_yet_again ; memory at @h[0] is poisoned
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2597
Dan Gohman32772f72011-12-06 03:35:58 +0000[diff] [blame]2598 store i32 %poison, i32* @g ; Poison value stored to memory.
2599 %poison2 = load i32* @g ; Poison value loaded back from memory.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2600
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]2601 store volatile i32 %poison, i32* @g ; External observation; undefined behavior.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2602
2603 %narrowaddr = bitcast i32* @g to i16*
2604 %wideaddr = bitcast i32* @g to i64*
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]2605 %poison3 = load i16* %narrowaddr ; Returns a poison value.
2606 %poison4 = load i64* %wideaddr ; Returns a poison value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2607
Dan Gohman5f115a72011-12-06 03:31:14 +0000[diff] [blame]2608 %cmp = icmp slt i32 %poison, 0 ; Returns a poison value.
2609 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2610
2611true:
Dan Gohman5f115a72011-12-06 03:31:14 +0000[diff] [blame]2612 store volatile i32 0, i32* @g ; This is control-dependent on %cmp, so
2613 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2614 br label %end
2615
2616end:
2617 %p = phi i32 [ 0, %entry ], [ 1, %true ]
Dan Gohman5f115a72011-12-06 03:31:14 +0000[diff] [blame]2618 ; Both edges into this PHI are
2619 ; control-dependent on %cmp, so this
2620 ; always results in a poison value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2621
Dan Gohman5f115a72011-12-06 03:31:14 +0000[diff] [blame]2622 store volatile i32 0, i32* @g ; This would depend on the store in %true
2623 ; if %cmp is true, or the store in %entry
2624 ; otherwise, so this is undefined behavior.
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2625
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2626 br i1 %cmp, label %second_true, label %second_end
Dan Gohman5f115a72011-12-06 03:31:14 +0000[diff] [blame]2627 ; The same branch again, but this time the
2628 ; true block doesn't have side effects.
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2629
2630second_true:
2631 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2632 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2633
2634second_end:
Dan Gohman5f115a72011-12-06 03:31:14 +0000[diff] [blame]2635 store volatile i32 0, i32* @g ; This time, the instruction always depends
2636 ; on the store in %end. Also, it is
2637 ; control-equivalent to %end, so this is
Dan Gohman32772f72011-12-06 03:35:58 +0000[diff] [blame]2638 ; well-defined (ignoring earlier undefined
2639 ; behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2640</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2641
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2642</div>
2643
2644<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2645<h3>
2646 <a name="blockaddress">Addresses of Basic Blocks</a>
2647</h3>
2648
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2649<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2650
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2651<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2652
2653<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2654 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2655 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2656
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2657<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2658 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2659 comparisons against null. Pointer equality tests between labels addresses
2660 results in undefined behavior &mdash; though, again, comparison against null
2661 is ok, and no label is equal to the null pointer. This may be passed around
2662 as an opaque pointer sized value as long as the bits are not inspected. This
2663 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2664 long as the original value is reconstituted before the <tt>indirectbr</tt>
2665 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2666
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2667<p>Finally, some targets may provide defined semantics when using the value as
2668 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2669
2670</div>
2671
2672
2673<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2674<h3>
2675 <a name="constantexprs">Constant Expressions</a>
2676</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2677
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2678<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2679
2680<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2681 to be used as constants. Constant expressions may be of
2682 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2683 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2684 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2685
2686<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2687 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2688 <dd>Truncate a constant to another type. The bit size of CST must be larger
2689 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2690
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2691 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2692 <dd>Zero extend a constant to another type. The bit size of CST must be
Duncan Sandsa522e562010-07-13 12:06:14 +0000[diff] [blame]2693 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2694
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2695 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2696 <dd>Sign extend a constant to another type. The bit size of CST must be
Duncan Sandsa522e562010-07-13 12:06:14 +0000[diff] [blame]2697 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2698
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2699 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2700 <dd>Truncate a floating point constant to another floating point type. The
2701 size of CST must be larger than the size of TYPE. Both types must be
2702 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2703
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2704 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2705 <dd>Floating point extend a constant to another type. The size of CST must be
2706 smaller or equal to the size of TYPE. Both types must be floating
2707 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2708
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2709 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2710 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2711 constant. TYPE must be a scalar or vector integer type. CST must be of
2712 scalar or vector floating point type. Both CST and TYPE must be scalars,
2713 or vectors of the same number of elements. If the value won't fit in the
2714 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2715
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2716 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2717 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2718 constant. TYPE must be a scalar or vector integer type. CST must be of
2719 scalar or vector floating point type. Both CST and TYPE must be scalars,
2720 or vectors of the same number of elements. If the value won't fit in the
2721 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2722
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2723 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2724 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2725 constant. TYPE must be a scalar or vector floating point type. CST must be
2726 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2727 vectors of the same number of elements. If the value won't fit in the
2728 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2729
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2730 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2731 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2732 constant. TYPE must be a scalar or vector floating point type. CST must be
2733 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2734 vectors of the same number of elements. If the value won't fit in the
2735 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2736
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2737 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2738 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2739 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2740 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2741 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2742
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2743 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2744 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2745 type. CST must be of integer type. The CST value is zero extended,
2746 truncated, or unchanged to make it fit in a pointer size. This one is
2747 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2748
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2749 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2750 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2751 are the same as those for the <a href="#i_bitcast">bitcast
2752 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2753
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2754 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2755 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2756 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2757 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2758 instruction, the index list may have zero or more indexes, which are
2759 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2760
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2761 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2762 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2763
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2764 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2765 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2766
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2767 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2768 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2769
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2770 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2771 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2772 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2773
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2774 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2775 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2776 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2777
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2778 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2779 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2780 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2781
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2782 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2783 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2784 constants. The index list is interpreted in a similar manner as indices in
2785 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2786 index value must be specified.</dd>
2787
2788 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2789 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2790 constants. The index list is interpreted in a similar manner as indices in
2791 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2792 index value must be specified.</dd>
2793
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2794 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2795 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2796 be any of the <a href="#binaryops">binary</a>
2797 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2798 on operands are the same as those for the corresponding instruction
2799 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2800</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2801
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2802</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2803
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2804</div>
2805
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2806<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2807<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2808<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2809<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2810<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2811<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2812<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2813</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2814
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2815<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2816
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2817<p>LLVM supports inline assembler expressions (as opposed
Bill Wendlingad8b58b2011-11-30 21:52:43 +0000[diff] [blame]2818 to <a href="#moduleasm">Module-Level Inline Assembly</a>) through the use of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2819 a special value. This value represents the inline assembler as a string
2820 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2821 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2822 expression has side effects, and a flag indicating whether the function
2823 containing the asm needs to align its stack conservatively. An example
2824 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2825
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2826<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2827i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2828</pre>
2829
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2830<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2831 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2832 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2833
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2834<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2835%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2836</pre>
2837
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2838<p>Inline asms with side effects not visible in the constraint list must be
2839 marked as having side effects. This is done through the use of the
2840 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2841
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2842<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2843call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2844</pre>
2845
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2846<p>In some cases inline asms will contain code that will not work unless the
2847 stack is aligned in some way, such as calls or SSE instructions on x86,
2848 yet will not contain code that does that alignment within the asm.
2849 The compiler should make conservative assumptions about what the asm might
2850 contain and should generate its usual stack alignment code in the prologue
2851 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2852
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2853<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2854call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2855</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2856
2857<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2858 first.</p>
2859
Bill Wendlingad8b58b2011-11-30 21:52:43 +0000[diff] [blame]2860<!--
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2861<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2862 documented here. Constraints on what can be done (e.g. duplication, moving,
2863 etc need to be documented). This is probably best done by reference to
2864 another document that covers inline asm from a holistic perspective.</p>
Bill Wendlingad8b58b2011-11-30 21:52:43 +0000[diff] [blame]2865 -->
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2866
Bill Wendlingad8b58b2011-11-30 21:52:43 +0000[diff] [blame]2867<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2868<h4>
Bill Wendlingad8b58b2011-11-30 21:52:43 +0000[diff] [blame]2869 <a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2870</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2871
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2872<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2873
Bill Wendlingad8b58b2011-11-30 21:52:43 +0000[diff] [blame]2874<p>The call instructions that wrap inline asm nodes may have a
2875 "<tt>!srcloc</tt>" MDNode attached to it that contains a list of constant
2876 integers. If present, the code generator will use the integer as the
2877 location cookie value when report errors through the <tt>LLVMContext</tt>
2878 error reporting mechanisms. This allows a front-end to correlate backend
2879 errors that occur with inline asm back to the source code that produced it.
2880 For example:</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2881
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2882<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2883call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2884...
2885!42 = !{ i32 1234567 }
2886</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2887
2888<p>It is up to the front-end to make sense of the magic numbers it places in the
Bill Wendlingad8b58b2011-11-30 21:52:43 +0000[diff] [blame]2889 IR. If the MDNode contains multiple constants, the code generator will use
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2890 the one that corresponds to the line of the asm that the error occurs on.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2891
2892</div>
2893
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2894</div>
2895
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2896<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2897<h3>
2898 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2899</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2900
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2901<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2902
2903<p>LLVM IR allows metadata to be attached to instructions in the program that
2904 can convey extra information about the code to the optimizers and code
2905 generator. One example application of metadata is source-level debug
2906 information. There are two metadata primitives: strings and nodes. All
2907 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2908 preceding exclamation point ('<tt>!</tt>').</p>
2909
2910<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlingb6c22202011-11-30 21:43:43 +0000[diff] [blame]2911 any character by escaping non-printable characters with "<tt>\xx</tt>" where
2912 "<tt>xx</tt>" is the two digit hex code. For example:
2913 "<tt>!"test\00"</tt>".</p>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2914
2915<p>Metadata nodes are represented with notation similar to structure constants
2916 (a comma separated list of elements, surrounded by braces and preceded by an
Bill Wendlingb6c22202011-11-30 21:43:43 +0000[diff] [blame]2917 exclamation point). Metadata nodes can have any values as their operand. For
2918 example:</p>
2919
2920<div class="doc_code">
2921<pre>
2922!{ metadata !"test\00", i32 10}
2923</pre>
2924</div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2925
2926<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2927 metadata nodes, which can be looked up in the module symbol table. For
Bill Wendlingb6c22202011-11-30 21:43:43 +0000[diff] [blame]2928 example:</p>
2929
2930<div class="doc_code">
2931<pre>
2932!foo = metadata !{!4, !3}
2933</pre>
2934</div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2935
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2936<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Bill Wendlingb6c22202011-11-30 21:43:43 +0000[diff] [blame]2937 function is using two metadata arguments:</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2938
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2939<div class="doc_code">
2940<pre>
2941call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2942</pre>
2943</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2944
2945<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Bill Wendlingb6c22202011-11-30 21:43:43 +0000[diff] [blame]2946 attached to the <tt>add</tt> instruction using the <tt>!dbg</tt>
2947 identifier:</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2948
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2949<div class="doc_code">
2950<pre>
2951%indvar.next = add i64 %indvar, 1, !dbg !21
2952</pre>
2953</div>
2954
Peter Collingbourneec9ff672011-10-27 19:19:07 +0000[diff] [blame]2955<p>More information about specific metadata nodes recognized by the optimizers
2956 and code generator is found below.</p>
2957
Bill Wendlingb6c22202011-11-30 21:43:43 +0000[diff] [blame]2958<!-- _______________________________________________________________________ -->
Peter Collingbourneec9ff672011-10-27 19:19:07 +0000[diff] [blame]2959<h4>
2960 <a name="tbaa">'<tt>tbaa</tt>' Metadata</a>
2961</h4>
2962
2963<div>
2964
2965<p>In LLVM IR, memory does not have types, so LLVM's own type system is not
2966 suitable for doing TBAA. Instead, metadata is added to the IR to describe
2967 a type system of a higher level language. This can be used to implement
2968 typical C/C++ TBAA, but it can also be used to implement custom alias
2969 analysis behavior for other languages.</p>
2970
2971<p>The current metadata format is very simple. TBAA metadata nodes have up to
2972 three fields, e.g.:</p>
2973
2974<div class="doc_code">
2975<pre>
2976!0 = metadata !{ metadata !"an example type tree" }
2977!1 = metadata !{ metadata !"int", metadata !0 }
2978!2 = metadata !{ metadata !"float", metadata !0 }
2979!3 = metadata !{ metadata !"const float", metadata !2, i64 1 }
2980</pre>
2981</div>
2982
2983<p>The first field is an identity field. It can be any value, usually
2984 a metadata string, which uniquely identifies the type. The most important
2985 name in the tree is the name of the root node. Two trees with
2986 different root node names are entirely disjoint, even if they
2987 have leaves with common names.</p>
2988
2989<p>The second field identifies the type's parent node in the tree, or
2990 is null or omitted for a root node. A type is considered to alias
2991 all of its descendants and all of its ancestors in the tree. Also,
2992 a type is considered to alias all types in other trees, so that
2993 bitcode produced from multiple front-ends is handled conservatively.</p>
2994
2995<p>If the third field is present, it's an integer which if equal to 1
2996 indicates that the type is "constant" (meaning
2997 <tt>pointsToConstantMemory</tt> should return true; see
2998 <a href="AliasAnalysis.html#OtherItfs">other useful
2999 <tt>AliasAnalysis</tt> methods</a>).</p>
3000
3001</div>
3002
Bill Wendlingb6c22202011-11-30 21:43:43 +0000[diff] [blame]3003<!-- _______________________________________________________________________ -->
Peter Collingbournef7d1e7b2011-10-27 19:19:14 +0000[diff] [blame]3004<h4>
Duncan Sands34bd91a2012-04-14 12:36:06 +0000[diff] [blame]3005 <a name="fpmath">'<tt>fpmath</tt>' Metadata</a>
Peter Collingbournef7d1e7b2011-10-27 19:19:14 +0000[diff] [blame]3006</h4>
3007
3008<div>
3009
Duncan Sands34bd91a2012-04-14 12:36:06 +0000[diff] [blame]3010<p><tt>fpmath</tt> metadata may be attached to any instruction of floating point
Duncan Sands05f4df82012-04-16 16:28:59 +0000[diff] [blame]3011 type. It can be used to express the maximum acceptable error in the result of
3012 that instruction, in ULPs, thus potentially allowing the compiler to use a
Duncan Sands9af62982012-04-16 19:39:33 +0000[diff] [blame]3013 more efficient but less accurate method of computing it. ULP is defined as
3014 follows:</p>
Peter Collingbournef7d1e7b2011-10-27 19:19:14 +0000[diff] [blame]3015
Bill Wendling302d7ce2011-11-09 19:33:56 +0000[diff] [blame]3016<blockquote>
3017
3018<p>If <tt>x</tt> is a real number that lies between two finite consecutive
3019 floating-point numbers <tt>a</tt> and <tt>b</tt>, without being equal to one
3020 of them, then <tt>ulp(x) = |b - a|</tt>, otherwise <tt>ulp(x)</tt> is the
3021 distance between the two non-equal finite floating-point numbers nearest
3022 <tt>x</tt>. Moreover, <tt>ulp(NaN)</tt> is <tt>NaN</tt>.</p>
3023
3024</blockquote>
Peter Collingbournef7d1e7b2011-10-27 19:19:14 +0000[diff] [blame]3025
Duncan Sands05f4df82012-04-16 16:28:59 +0000[diff] [blame]3026<p>The metadata node shall consist of a single positive floating point number
Duncan Sands9af62982012-04-16 19:39:33 +0000[diff] [blame]3027 representing the maximum relative error, for example:</p>
Peter Collingbournef7d1e7b2011-10-27 19:19:14 +0000[diff] [blame]3028
3029<div class="doc_code">
3030<pre>
Duncan Sands05f4df82012-04-16 16:28:59 +0000[diff] [blame]3031!0 = metadata !{ float 2.5 } ; maximum acceptable inaccuracy is 2.5 ULPs
Peter Collingbournef7d1e7b2011-10-27 19:19:14 +0000[diff] [blame]3032</pre>
3033</div>
3034
NAKAMURA Takumic9d9b922012-03-27 11:25:16 +0000[diff] [blame]3035</div>
3036
Rafael Espindolaef9f5502012-03-24 00:14:51 +0000[diff] [blame]3037<!-- _______________________________________________________________________ -->
3038<h4>
3039 <a name="range">'<tt>range</tt>' Metadata</a>
3040</h4>
3041
3042<div>
3043<p><tt>range</tt> metadata may be attached only to loads of integer types. It
3044 expresses the possible ranges the loaded value is in. The ranges are
3045 represented with a flattened list of integers. The loaded value is known to
3046 be in the union of the ranges defined by each consecutive pair. Each pair
3047 has the following properties:</p>
3048<ul>
3049 <li>The type must match the type loaded by the instruction.</li>
3050 <li>The pair <tt>a,b</tt> represents the range <tt>[a,b)</tt>.</li>
3051 <li>Both <tt>a</tt> and <tt>b</tt> are constants.</li>
3052 <li>The range is allowed to wrap.</li>
3053 <li>The range should not represent the full or empty set. That is,
3054 <tt>a!=b</tt>. </li>
3055</ul>
3056
3057<p>Examples:</p>
3058<div class="doc_code">
3059<pre>
3060 %a = load i8* %x, align 1, !range !0 ; Can only be 0 or 1
3061 %b = load i8* %y, align 1, !range !1 ; Can only be 255 (-1), 0 or 1
3062 %c = load i8* %z, align 1, !range !2 ; Can only be 0, 1, 3, 4 or 5
3063...
3064!0 = metadata !{ i8 0, i8 2 }
3065!1 = metadata !{ i8 255, i8 2 }
3066!2 = metadata !{ i8 0, i8 2, i8 3, i8 6 }
3067</pre>
3068</div>
3069</div>
Peter Collingbournef7d1e7b2011-10-27 19:19:14 +0000[diff] [blame]3070</div>
3071
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]3072</div>
3073
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3074<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3075<h2>
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]3076 <a name="module_flags">Module Flags Metadata</a>
3077</h2>
3078<!-- *********************************************************************** -->
3079
3080<div>
3081
3082<p>Information about the module as a whole is difficult to convey to LLVM's
3083 subsystems. The LLVM IR isn't sufficient to transmit this
3084 information. The <tt>llvm.module.flags</tt> named metadata exists in order to
3085 facilitate this. These flags are in the form of key / value pairs &mdash;
3086 much like a dictionary &mdash; making it easy for any subsystem who cares
3087 about a flag to look it up.</p>
3088
3089<p>The <tt>llvm.module.flags</tt> metadata contains a list of metadata
3090 triplets. Each triplet has the following form:</p>
3091
3092<ul>
3093 <li>The first element is a <i>behavior</i> flag, which specifies the behavior
3094 when two (or more) modules are merged together, and it encounters two (or
3095 more) metadata with the same ID. The supported behaviors are described
3096 below.</li>
3097
3098 <li>The second element is a metadata string that is a unique ID for the
3099 metadata. How each ID is interpreted is documented below.</li>
3100
3101 <li>The third element is the value of the flag.</li>
3102</ul>
3103
3104<p>When two (or more) modules are merged together, the resulting
3105 <tt>llvm.module.flags</tt> metadata is the union of the
3106 modules' <tt>llvm.module.flags</tt> metadata. The only exception being a flag
3107 with the <i>Override</i> behavior, which may override another flag's value
3108 (see below).</p>
3109
3110<p>The following behaviors are supported:</p>
3111
3112<table border="1" cellspacing="0" cellpadding="4">
3113 <tbody>
3114 <tr>
3115 <th>Value</th>
3116 <th>Behavior</th>
3117 </tr>
3118 <tr>
3119 <td>1</td>
3120 <td align="left">
Bill Wendlingd672d9c2012-03-06 09:17:04 +0000[diff] [blame]3121 <dl>
3122 <dt><b>Error</b></dt>
3123 <dd>Emits an error if two values disagree. It is an error to have an ID
3124 with both an Error and a Warning behavior.</dd>
3125 </dl>
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]3126 </td>
3127 </tr>
3128 <tr>
3129 <td>2</td>
3130 <td align="left">
Bill Wendlingd672d9c2012-03-06 09:17:04 +0000[diff] [blame]3131 <dl>
3132 <dt><b>Warning</b></dt>
3133 <dd>Emits a warning if two values disagree.</dd>
3134 </dl>
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]3135 </td>
3136 </tr>
3137 <tr>
3138 <td>3</td>
3139 <td align="left">
Bill Wendlingd672d9c2012-03-06 09:17:04 +0000[diff] [blame]3140 <dl>
3141 <dt><b>Require</b></dt>
3142 <dd>Emits an error when the specified value is not present or doesn't
3143 have the specified value. It is an error for two (or more)
3144 <tt>llvm.module.flags</tt> with the same ID to have the Require
3145 behavior but different values. There may be multiple Require flags
3146 per ID.</dd>
3147 </dl>
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]3148 </td>
3149 </tr>
3150 <tr>
3151 <td>4</td>
3152 <td align="left">
Bill Wendlingd672d9c2012-03-06 09:17:04 +0000[diff] [blame]3153 <dl>
3154 <dt><b>Override</b></dt>
3155 <dd>Uses the specified value if the two values disagree. It is an
3156 error for two (or more) <tt>llvm.module.flags</tt> with the same
3157 ID to have the Override behavior but different values.</dd>
3158 </dl>
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]3159 </td>
3160 </tr>
3161 </tbody>
3162</table>
3163
3164<p>An example of module flags:</p>
3165
3166<pre class="doc_code">
3167!0 = metadata !{ i32 1, metadata !"foo", i32 1 }
3168!1 = metadata !{ i32 4, metadata !"bar", i32 37 }
3169!2 = metadata !{ i32 2, metadata !"qux", i32 42 }
3170!3 = metadata !{ i32 3, metadata !"qux",
3171 metadata !{
3172 metadata !"foo", i32 1
3173 }
3174}
3175!llvm.module.flags = !{ !0, !1, !2, !3 }
3176</pre>
3177
3178<ul>
3179 <li><p>Metadata <tt>!0</tt> has the ID <tt>!"foo"</tt> and the value '1'. The
3180 behavior if two or more <tt>!"foo"</tt> flags are seen is to emit an
3181 error if their values are not equal.</p></li>
3182
3183 <li><p>Metadata <tt>!1</tt> has the ID <tt>!"bar"</tt> and the value '37'. The
3184 behavior if two or more <tt>!"bar"</tt> flags are seen is to use the
3185 value '37' if their values are not equal.</p></li>
3186
3187 <li><p>Metadata <tt>!2</tt> has the ID <tt>!"qux"</tt> and the value '42'. The
3188 behavior if two or more <tt>!"qux"</tt> flags are seen is to emit a
3189 warning if their values are not equal.</p></li>
3190
3191 <li><p>Metadata <tt>!3</tt> has the ID <tt>!"qux"</tt> and the value:</p>
3192
3193<pre class="doc_code">
3194metadata !{ metadata !"foo", i32 1 }
3195</pre>
Bill Wendling73462772012-02-16 01:10:50 +0000[diff] [blame]3196
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]3197 <p>The behavior is to emit an error if the <tt>llvm.module.flags</tt> does
3198 not contain a flag with the ID <tt>!"foo"</tt> that has the value
3199 '1'. If two or more <tt>!"qux"</tt> flags exist, then they must have
3200 the same value or an error will be issued.</p></li>
3201</ul>
3202
Bill Wendling73462772012-02-16 01:10:50 +0000[diff] [blame]3203
3204<!-- ======================================================================= -->
3205<h3>
3206<a name="objc_gc_flags">Objective-C Garbage Collection Module Flags Metadata</a>
3207</h3>
3208
3209<div>
3210
3211<p>On the Mach-O platform, Objective-C stores metadata about garbage collection
3212 in a special section called "image info". The metadata consists of a version
3213 number and a bitmask specifying what types of garbage collection are
3214 supported (if any) by the file. If two or more modules are linked together
3215 their garbage collection metadata needs to be merged rather than appended
3216 together.</p>
3217
3218<p>The Objective-C garbage collection module flags metadata consists of the
3219 following key-value pairs:</p>
3220
3221<table border="1" cellspacing="0" cellpadding="4">
Bill Wendling4fa13cc2012-03-06 09:23:25 +0000[diff] [blame]3222 <col width="30%">
Bill Wendling73462772012-02-16 01:10:50 +0000[diff] [blame]3223 <tbody>
3224 <tr>
Bill Wendlingd672d9c2012-03-06 09:17:04 +0000[diff] [blame]3225 <th>Key</th>
Bill Wendling73462772012-02-16 01:10:50 +0000[diff] [blame]3226 <th>Value</th>
3227 </tr>
3228 <tr>
3229 <td><tt>Objective-C&nbsp;Version</tt></td>
3230 <td align="left"><b>[Required]</b> &mdash; The Objective-C ABI
3231 version. Valid values are 1 and 2.</td>
3232 </tr>
3233 <tr>
3234 <td><tt>Objective-C&nbsp;Image&nbsp;Info&nbsp;Version</tt></td>
3235 <td align="left"><b>[Required]</b> &mdash; The version of the image info
3236 section. Currently always 0.</td>
3237 </tr>
3238 <tr>
3239 <td><tt>Objective-C&nbsp;Image&nbsp;Info&nbsp;Section</tt></td>
3240 <td align="left"><b>[Required]</b> &mdash; The section to place the
3241 metadata. Valid values are <tt>"__OBJC, __image_info, regular"</tt> for
3242 Objective-C ABI version 1, and <tt>"__DATA,__objc_imageinfo, regular,
3243 no_dead_strip"</tt> for Objective-C ABI version 2.</td>
3244 </tr>
3245 <tr>
3246 <td><tt>Objective-C&nbsp;Garbage&nbsp;Collection</tt></td>
3247 <td align="left"><b>[Required]</b> &mdash; Specifies whether garbage
3248 collection is supported or not. Valid values are 0, for no garbage
3249 collection, and 2, for garbage collection supported.</td>
3250 </tr>
3251 <tr>
3252 <td><tt>Objective-C&nbsp;GC&nbsp;Only</tt></td>
3253 <td align="left"><b>[Optional]</b> &mdash; Specifies that only garbage
3254 collection is supported. If present, its value must be 6. This flag
3255 requires that the <tt>Objective-C Garbage Collection</tt> flag have the
3256 value 2.</td>
3257 </tr>
3258 </tbody>
3259</table>
3260
3261<p>Some important flag interactions:</p>
3262
3263<ul>
3264 <li>If a module with <tt>Objective-C Garbage Collection</tt> set to 0 is
3265 merged with a module with <tt>Objective-C Garbage Collection</tt> set to
3266 2, then the resulting module has the <tt>Objective-C Garbage
3267 Collection</tt> flag set to 0.</li>
3268
3269 <li>A module with <tt>Objective-C Garbage Collection</tt> set to 0 cannot be
3270 merged with a module with <tt>Objective-C GC Only</tt> set to 6.</li>
3271</ul>
3272
3273</div>
3274
Bill Wendling911fdf42012-02-11 11:59:36 +0000[diff] [blame]3275</div>
3276
3277<!-- *********************************************************************** -->
3278<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3279 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3280</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3281<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3282<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3283<p>LLVM has a number of "magic" global variables that contain data that affect
3284code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]3285of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
3286section and all globals that start with "<tt>llvm.</tt>" are reserved for use
3287by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3288
3289<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3290<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3291<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3292</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3293
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3294<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3295
3296<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
3297href="#linkage_appending">appending linkage</a>. This array contains a list of
3298pointers to global variables and functions which may optionally have a pointer
3299cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
3300
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3301<div class="doc_code">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3302<pre>
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3303@X = global i8 4
3304@Y = global i32 123
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3305
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3306@llvm.used = appending global [2 x i8*] [
3307 i8* @X,
3308 i8* bitcast (i32* @Y to i8*)
3309], section "llvm.metadata"
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3310</pre>
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3311</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3312
3313<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3314 compiler, assembler, and linker are required to treat the symbol as if there
3315 is a reference to the global that it cannot see. For example, if a variable
3316 has internal linkage and no references other than that from
3317 the <tt>@llvm.used</tt> list, it cannot be deleted. This is commonly used to
3318 represent references from inline asms and other things the compiler cannot
3319 "see", and corresponds to "<tt>attribute((used))</tt>" in GNU C.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3320
3321<p>On some targets, the code generator must emit a directive to the assembler or
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3322 object file to prevent the assembler and linker from molesting the
3323 symbol.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3324
3325</div>
3326
3327<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3328<h3>
3329 <a name="intg_compiler_used">
3330 The '<tt>llvm.compiler.used</tt>' Global Variable
3331 </a>
3332</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]3333
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3334<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]3335
3336<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3337 <tt>@llvm.used</tt> directive, except that it only prevents the compiler from
3338 touching the symbol. On targets that support it, this allows an intelligent
3339 linker to optimize references to the symbol without being impeded as it would
3340 be by <tt>@llvm.used</tt>.</p>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]3341
3342<p>This is a rare construct that should only be used in rare circumstances, and
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3343 should not be exposed to source languages.</p>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]3344
3345</div>
3346
3347<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3348<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3349<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3350</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3351
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3352<div>
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3353
3354<div class="doc_code">
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]3355<pre>
3356%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]3357@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]3358</pre>
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3359</div>
3360
3361<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor
3362 functions and associated priorities. The functions referenced by this array
3363 will be called in ascending order of priority (i.e. lowest first) when the
3364 module is loaded. The order of functions with the same priority is not
3365 defined.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3366
3367</div>
3368
3369<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3370<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3371<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3372</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3373
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3374<div>
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3375
3376<div class="doc_code">
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]3377<pre>
3378%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]3379@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]3380</pre>
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3381</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3382
Bill Wendling1654bb22011-11-08 00:32:45 +0000[diff] [blame]3383<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions
3384 and associated priorities. The functions referenced by this array will be
3385 called in descending order of priority (i.e. highest first) when the module
3386 is loaded. The order of functions with the same priority is not defined.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3387
3388</div>
3389
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3390</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3391
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]3392<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3393<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3394<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3395
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3396<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3397
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3398<p>The LLVM instruction set consists of several different classifications of
3399 instructions: <a href="#terminators">terminator
3400 instructions</a>, <a href="#binaryops">binary instructions</a>,
3401 <a href="#bitwiseops">bitwise binary instructions</a>,
3402 <a href="#memoryops">memory instructions</a>, and
3403 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3404
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3405<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3406<h3>
3407 <a name="terminators">Terminator Instructions</a>
3408</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3409
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3410<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3411
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3412<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3413 in a program ends with a "Terminator" instruction, which indicates which
3414 block should be executed after the current block is finished. These
3415 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3416 control flow, not values (the one exception being the
3417 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3418
Chris Lattnerd3d65ab2011-08-02 20:29:13 +0000[diff] [blame]3419<p>The terminator instructions are:
3420 '<a href="#i_ret"><tt>ret</tt></a>',
3421 '<a href="#i_br"><tt>br</tt></a>',
3422 '<a href="#i_switch"><tt>switch</tt></a>',
3423 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>',
3424 '<a href="#i_invoke"><tt>invoke</tt></a>',
Chris Lattnerd3d65ab2011-08-02 20:29:13 +0000[diff] [blame]3425 '<a href="#i_resume"><tt>resume</tt></a>', and
3426 '<a href="#i_unreachable"><tt>unreachable</tt></a>'.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3427
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3428<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3429<h4>
3430 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3431</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3432
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3433<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3434
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3435<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3436<pre>
3437 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3438 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3439</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3440
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3441<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3442<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3443 a value) from a function back to the caller.</p>
3444
3445<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3446 value and then causes control flow, and one that just causes control flow to
3447 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3448
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3449<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3450<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3451 return value. The type of the return value must be a
3452 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3453
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3454<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3455 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3456 value or a return value with a type that does not match its type, or if it
3457 has a void return type and contains a '<tt>ret</tt>' instruction with a
3458 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3459
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3460<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3461<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3462 the calling function's context. If the caller is a
3463 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3464 instruction after the call. If the caller was an
3465 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3466 the beginning of the "normal" destination block. If the instruction returns
3467 a value, that value shall set the call or invoke instruction's return
3468 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3469
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3470<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3471<pre>
3472 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3473 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]3474 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3475</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3476
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3477</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3478<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3479<h4>
3480 <a name="i_br">'<tt>br</tt>' Instruction</a>
3481</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3482
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3483<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3484
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3485<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3486<pre>
Bill Wendling16b86742011-07-26 10:41:15 +0000[diff] [blame]3487 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3488 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3489</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3490
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3491<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3492<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3493 different basic block in the current function. There are two forms of this
3494 instruction, corresponding to a conditional branch and an unconditional
3495 branch.</p>
3496
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3497<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3498<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3499 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3500 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3501 target.</p>
3502
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3503<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3504<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3505 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3506 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3507 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3508
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3509<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3510<pre>
3511Test:
3512 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3513 br i1 %cond, label %IfEqual, label %IfUnequal
3514IfEqual:
3515 <a href="#i_ret">ret</a> i32 1
3516IfUnequal:
3517 <a href="#i_ret">ret</a> i32 0
3518</pre>
3519
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3520</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3521
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3522<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3523<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3524 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3525</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3526
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3527<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3528
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3529<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3530<pre>
3531 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3532</pre>
3533
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3534<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3535<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3536 several different places. It is a generalization of the '<tt>br</tt>'
3537 instruction, allowing a branch to occur to one of many possible
3538 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3539
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3540<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3541<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3542 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3543 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3544 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3545
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3546<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3547<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3548 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3549 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3550 transferred to the corresponding destination; otherwise, control flow is
3551 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3552
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3553<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3554<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3555 <tt>switch</tt> instruction, this instruction may be code generated in
3556 different ways. For example, it could be generated as a series of chained
3557 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3558
3559<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3560<pre>
3561 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3562 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3563 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3564
3565 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3566 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3567
3568 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3569 switch i32 %val, label %otherwise [ i32 0, label %onzero
3570 i32 1, label %onone
3571 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3572</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3573
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3574</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3575
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3576
3577<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3578<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3579 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3580</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3581
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3582<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3583
3584<h5>Syntax:</h5>
3585<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3586 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3587</pre>
3588
3589<h5>Overview:</h5>
3590
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3591<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3592 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3593 "<tt>address</tt>". Address must be derived from a <a
3594 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3595
3596<h5>Arguments:</h5>
3597
3598<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3599 rest of the arguments indicate the full set of possible destinations that the
3600 address may point to. Blocks are allowed to occur multiple times in the
3601 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3602
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3603<p>This destination list is required so that dataflow analysis has an accurate
3604 understanding of the CFG.</p>
3605
3606<h5>Semantics:</h5>
3607
3608<p>Control transfers to the block specified in the address argument. All
3609 possible destination blocks must be listed in the label list, otherwise this
3610 instruction has undefined behavior. This implies that jumps to labels
3611 defined in other functions have undefined behavior as well.</p>
3612
3613<h5>Implementation:</h5>
3614
3615<p>This is typically implemented with a jump through a register.</p>
3616
3617<h5>Example:</h5>
3618<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3619 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3620</pre>
3621
3622</div>
3623
3624
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3625<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3626<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3627 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3628</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3629
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3630<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3631
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3632<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3633<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3634 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]3635 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3636</pre>
3637
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3638<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3639<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3640 function, with the possibility of control flow transfer to either the
3641 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3642 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3643 control flow will return to the "normal" label. If the callee (or any
Bill Wendling3f6a3a22012-02-06 21:57:33 +0000[diff] [blame]3644 indirect callees) returns via the "<a href="#i_resume"><tt>resume</tt></a>"
3645 instruction or other exception handling mechanism, control is interrupted and
3646 continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3647
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3648<p>The '<tt>exception</tt>' label is a
3649 <i><a href="ExceptionHandling.html#overview">landing pad</a></i> for the
3650 exception. As such, '<tt>exception</tt>' label is required to have the
3651 "<a href="#i_landingpad"><tt>landingpad</tt></a>" instruction, which contains
Chad Rosierc28f3e92011-12-09 02:00:44 +0000[diff] [blame]3652 the information about the behavior of the program after unwinding
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3653 happens, as its first non-PHI instruction. The restrictions on the
3654 "<tt>landingpad</tt>" instruction's tightly couples it to the
3655 "<tt>invoke</tt>" instruction, so that the important information contained
3656 within the "<tt>landingpad</tt>" instruction can't be lost through normal
3657 code motion.</p>
3658
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3659<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3660<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3661
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3662<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3663 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3664 convention</a> the call should use. If none is specified, the call
3665 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3666
3667 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3668 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3669 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3670
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3671 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3672 function value being invoked. In most cases, this is a direct function
3673 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3674 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3675
3676 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3677 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3678
3679 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3680 signature argument types and parameter attributes. All arguments must be
3681 of <a href="#t_firstclass">first class</a> type. If the function
3682 signature indicates the function accepts a variable number of arguments,
3683 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3684
3685 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3686 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3687
Bill Wendling3f6a3a22012-02-06 21:57:33 +0000[diff] [blame]3688 <li>'<tt>exception label</tt>': the label reached when a callee returns via
3689 the <a href="#i_resume"><tt>resume</tt></a> instruction or other exception
3690 handling mechanism.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3691
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3692 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3693 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3694 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3695</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3696
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3697<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3698<p>This instruction is designed to operate as a standard
3699 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3700 primary difference is that it establishes an association with a label, which
3701 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3702
3703<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3704 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3705 exception. Additionally, this is important for implementation of
3706 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3707
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3708<p>For the purposes of the SSA form, the definition of the value returned by the
3709 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3710 block to the "normal" label. If the callee unwinds then no return value is
3711 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3712
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3713<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3714<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3715 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3716 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3717 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3718 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3719</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3720
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3721</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3722
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3723 <!-- _______________________________________________________________________ -->
3724
3725<h4>
3726 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3727</h4>
3728
3729<div>
3730
3731<h5>Syntax:</h5>
3732<pre>
3733 resume &lt;type&gt; &lt;value&gt;
3734</pre>
3735
3736<h5>Overview:</h5>
3737<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3738 successors.</p>
3739
3740<h5>Arguments:</h5>
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3741<p>The '<tt>resume</tt>' instruction requires one argument, which must have the
Bill Wendlingc5a13612011-08-03 18:37:32 +0000[diff] [blame]3742 same type as the result of any '<tt>landingpad</tt>' instruction in the same
3743 function.</p>
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3744
3745<h5>Semantics:</h5>
3746<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3747 (in-flight) exception whose unwinding was interrupted with
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3748 a <a href="#i_landingpad"><tt>landingpad</tt></a> instruction.</p>
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3749
3750<h5>Example:</h5>
3751<pre>
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3752 resume { i8*, i32 } %exn
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3753</pre>
3754
3755</div>
3756
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3757<!-- _______________________________________________________________________ -->
3758
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3759<h4>
3760 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3761</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3762
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3763<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3764
3765<h5>Syntax:</h5>
3766<pre>
3767 unreachable
3768</pre>
3769
3770<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3771<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3772 instruction is used to inform the optimizer that a particular portion of the
3773 code is not reachable. This can be used to indicate that the code after a
3774 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3775
3776<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3777<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3778
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3779</div>
3780
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3781</div>
3782
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3783<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3784<h3>
3785 <a name="binaryops">Binary Operations</a>
3786</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3787
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3788<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3789
3790<p>Binary operators are used to do most of the computation in a program. They
3791 require two operands of the same type, execute an operation on them, and
3792 produce a single value. The operands might represent multiple data, as is
3793 the case with the <a href="#t_vector">vector</a> data type. The result value
3794 has the same type as its operands.</p>
3795
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3796<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3797
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3798<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3799<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3800 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3801</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3802
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3803<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3804
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3805<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3806<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3807 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3808 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3809 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3810 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3811</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3812
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3813<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3814<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3815
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3816<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3817<p>The two arguments to the '<tt>add</tt>' instruction must
3818 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3819 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3820
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3821<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3822<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3823
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3824<p>If the sum has unsigned overflow, the result returned is the mathematical
3825 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3826
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3827<p>Because LLVM integers use a two's complement representation, this instruction
3828 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3829
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3830<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3831 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3832 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]3833 is a <a href="#poisonvalues">poison value</a> if unsigned and/or signed overflow,
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3834 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3835
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3836<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3837<pre>
3838 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3839</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3840
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3841</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3842
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3843<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3844<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3845 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3846</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3847
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3848<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3849
3850<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3851<pre>
3852 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3853</pre>
3854
3855<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3856<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3857
3858<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3859<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3860 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3861 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3862
3863<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3864<p>The value produced is the floating point sum of the two operands.</p>
3865
3866<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3867<pre>
3868 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3869</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3870
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3871</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3872
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3873<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3874<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3875 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3876</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3877
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3878<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3879
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3880<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3881<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3882 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3883 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3884 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3885 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3886</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3887
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3888<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3889<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3890 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3891
3892<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3893 '<tt>neg</tt>' instruction present in most other intermediate
3894 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3895
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3896<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3897<p>The two arguments to the '<tt>sub</tt>' instruction must
3898 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3899 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3900
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3901<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3902<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3903
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3904<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3905 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3906 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3907
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3908<p>Because LLVM integers use a two's complement representation, this instruction
3909 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3910
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3911<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3912 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3913 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]3914 is a <a href="#poisonvalues">poison value</a> if unsigned and/or signed overflow,
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3915 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3916
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3917<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3918<pre>
3919 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3920 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3921</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3922
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3923</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3924
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3925<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3926<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3927 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3928</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3929
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3930<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3931
3932<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3933<pre>
3934 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3935</pre>
3936
3937<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3938<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3939 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3940
3941<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3942 '<tt>fneg</tt>' instruction present in most other intermediate
3943 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3944
3945<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3946<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3947 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3948 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3949
3950<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3951<p>The value produced is the floating point difference of the two operands.</p>
3952
3953<h5>Example:</h5>
3954<pre>
3955 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3956 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3957</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3958
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3959</div>
3960
3961<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3962<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3963 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3964</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3965
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3966<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3967
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3968<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3969<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3970 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3971 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3972 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3973 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3974</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3975
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3976<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3977<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3978
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3979<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3980<p>The two arguments to the '<tt>mul</tt>' instruction must
3981 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3982 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3983
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3984<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3985<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3986
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3987<p>If the result of the multiplication has unsigned overflow, the result
3988 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3989 width of the result.</p>
3990
3991<p>Because LLVM integers use a two's complement representation, and the result
3992 is the same width as the operands, this instruction returns the correct
3993 result for both signed and unsigned integers. If a full product
3994 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3995 be sign-extended or zero-extended as appropriate to the width of the full
3996 product.</p>
3997
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3998<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3999 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
4000 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]4001 is a <a href="#poisonvalues">poison value</a> if unsigned and/or signed overflow,
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]4002 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]4003
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4004<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4005<pre>
4006 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4007</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4008
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4009</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4010
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4011<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4012<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4013 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4014</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4015
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4016<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4017
4018<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4019<pre>
4020 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4021</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4022
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4023<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4024<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4025
4026<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4027<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4028 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
4029 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4030
4031<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4032<p>The value produced is the floating point product of the two operands.</p>
4033
4034<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4035<pre>
4036 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4037</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4038
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]4039</div>
4040
4041<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4042<h4>
4043 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
4044</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4045
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4046<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4047
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4048<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4049<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]4050 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4051 &lt;result&gt; = udiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4052</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4053
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4054<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4055<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4056
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4057<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4058<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4059 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4060 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4061
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4062<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4063<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4064
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4065<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4066 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
4067
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4068<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4069
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]4070<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]4071 <tt>udiv</tt> is a <a href="#poisonvalues">poison value</a> if %op1 is not a
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]4072 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
4073
4074
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4075<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4076<pre>
4077 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4078</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4079
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4080</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4081
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4082<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4083<h4>
4084 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
4085</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4086
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4087<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4088
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4089<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4090<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]4091 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]4092 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4093</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4094
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4095<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4096<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4097
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4098<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4099<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4100 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4101 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4102
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4103<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4104<p>The value produced is the signed integer quotient of the two operands rounded
4105 towards zero.</p>
4106
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4107<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4108 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
4109
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4110<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4111 undefined behavior; this is a rare case, but can occur, for example, by doing
4112 a 32-bit division of -2147483648 by -1.</p>
4113
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]4114<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]4115 <tt>sdiv</tt> is a <a href="#poisonvalues">poison value</a> if the result would
Dan Gohmane501ff72010-07-11 00:08:34 +0000[diff] [blame]4116 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]4117
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4118<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4119<pre>
4120 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4121</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4122
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4123</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4124
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4125<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4126<h4>
4127 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
4128</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4129
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4130<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4131
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4132<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4133<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4134 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4135</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4136
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4137<h5>Overview:</h5>
4138<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4139
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4140<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4141<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4142 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
4143 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4144
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4145<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]4146<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4147
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4148<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4149<pre>
4150 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4151</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4152
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4153</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4154
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4155<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4156<h4>
4157 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
4158</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4159
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4160<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4161
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4162<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4163<pre>
4164 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4165</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4166
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4167<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4168<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
4169 division of its two arguments.</p>
4170
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4171<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4172<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4173 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4174 values. Both arguments must have identical types.</p>
4175
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4176<h5>Semantics:</h5>
4177<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4178 This instruction always performs an unsigned division to get the
4179 remainder.</p>
4180
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4181<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4182 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
4183
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4184<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4185
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4186<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4187<pre>
4188 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4189</pre>
4190
4191</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4192
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4193<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4194<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4195 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4196</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4197
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4198<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4199
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4200<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4201<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4202 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4203</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4204
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4205<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4206<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
4207 division of its two operands. This instruction can also take
4208 <a href="#t_vector">vector</a> versions of the values in which case the
4209 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]4210
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4211<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4212<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4213 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4214 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4215
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4216<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4217<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]4218 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
4219 <i>modulo</i> operator (where the result is either zero or has the same sign
4220 as the divisor, <tt>op2</tt>) of a value.
4221 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4222 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
4223 Math Forum</a>. For a table of how this is implemented in various languages,
4224 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
4225 Wikipedia: modulo operation</a>.</p>
4226
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4227<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4228 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
4229
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]4230<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4231 Overflow also leads to undefined behavior; this is a rare case, but can
4232 occur, for example, by taking the remainder of a 32-bit division of
4233 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
4234 lets srem be implemented using instructions that return both the result of
4235 the division and the remainder.)</p>
4236
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4237<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4238<pre>
4239 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4240</pre>
4241
4242</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4243
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4244<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4245<h4>
4246 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
4247</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4248
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4249<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4250
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4251<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4252<pre>
4253 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4254</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4255
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4256<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4257<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
4258 its two operands.</p>
4259
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4260<h5>Arguments:</h5>
4261<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4262 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
4263 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4264
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4265<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4266<p>This instruction returns the <i>remainder</i> of a division. The remainder
4267 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4268
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]4269<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4270<pre>
4271 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4272</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4273
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4274</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]4275
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4276</div>
4277
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]4278<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4279<h3>
4280 <a name="bitwiseops">Bitwise Binary Operations</a>
4281</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4282
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4283<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4284
4285<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
4286 program. They are generally very efficient instructions and can commonly be
4287 strength reduced from other instructions. They require two operands of the
4288 same type, execute an operation on them, and produce a single value. The
4289 resulting value is the same type as its operands.</p>
4290
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4291<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4292<h4>
4293 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
4294</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4295
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4296<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4297
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4298<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4299<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4300 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4301 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4302 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4303 &lt;result&gt; = shl nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4304</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4305
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4306<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4307<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
4308 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4309
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4310<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4311<p>Both arguments to the '<tt>shl</tt>' instruction must be the
4312 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
4313 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4314
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4315<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4316<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
4317 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
4318 is (statically or dynamically) negative or equal to or larger than the number
4319 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4320 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4321 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4322
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4323<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]4324 <a href="#poisonvalues">poison value</a> if it shifts out any non-zero bits. If
Chris Lattnerf10dfdc2011-02-09 16:44:44 +0000[diff] [blame]4325 the <tt>nsw</tt> keyword is present, then the shift produces a
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]4326 <a href="#poisonvalues">poison value</a> if it shifts out any bits that disagree
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4327 with the resultant sign bit. As such, NUW/NSW have the same semantics as
4328 they would if the shift were expressed as a mul instruction with the same
4329 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
4330
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4331<h5>Example:</h5>
4332<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4333 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
4334 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
4335 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4336 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4337 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4338</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4339
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4340</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4341
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4342<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4343<h4>
4344 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
4345</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4346
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4347<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4348
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4349<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4350<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4351 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4352 &lt;result&gt; = lshr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4353</pre>
4354
4355<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4356<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
4357 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4358
4359<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4360<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4361 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4362 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4363
4364<h5>Semantics:</h5>
4365<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4366 significant bits of the result will be filled with zero bits after the shift.
4367 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
4368 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4369 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4370 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4371
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4372<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]4373 <tt>lshr</tt> is a <a href="#poisonvalues">poison value</a> if any of the bits
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4374 shifted out are non-zero.</p>
4375
4376
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4377<h5>Example:</h5>
4378<pre>
4379 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4380 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4381 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4382 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4383 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4384 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4385</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4386
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4387</div>
4388
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]4389<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4390<h4>
4391 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4392</h4>
4393
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4394<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4395
4396<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4397<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4398 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4399 &lt;result&gt; = ashr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4400</pre>
4401
4402<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4403<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4404 operand shifted to the right a specified number of bits with sign
4405 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4406
4407<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4408<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4409 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4410 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4411
4412<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4413<p>This instruction always performs an arithmetic shift right operation, The
4414 most significant bits of the result will be filled with the sign bit
4415 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4416 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4417 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4418 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4419
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4420<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]4421 <tt>ashr</tt> is a <a href="#poisonvalues">poison value</a> if any of the bits
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4422 shifted out are non-zero.</p>
4423
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4424<h5>Example:</h5>
4425<pre>
4426 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4427 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4428 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4429 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4430 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4431 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4432</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4433
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4434</div>
4435
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4436<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4437<h4>
4438 <a name="i_and">'<tt>and</tt>' Instruction</a>
4439</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4440
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4441<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4442
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4443<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4444<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4445 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4446</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4447
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4448<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4449<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4450 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4451
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4452<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4453<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4454 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4455 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4456
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4457<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4458<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4459
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4460<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4461 <tbody>
4462 <tr>
Bill Wendling4517fe52011-12-09 22:41:40 +0000[diff] [blame]4463 <th>In0</th>
4464 <th>In1</th>
4465 <th>Out</th>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4466 </tr>
4467 <tr>
4468 <td>0</td>
4469 <td>0</td>
4470 <td>0</td>
4471 </tr>
4472 <tr>
4473 <td>0</td>
4474 <td>1</td>
4475 <td>0</td>
4476 </tr>
4477 <tr>
4478 <td>1</td>
4479 <td>0</td>
4480 <td>0</td>
4481 </tr>
4482 <tr>
4483 <td>1</td>
4484 <td>1</td>
4485 <td>1</td>
4486 </tr>
4487 </tbody>
4488</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4489
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4490<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4491<pre>
4492 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4493 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4494 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4495</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4496</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4497<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4498<h4>
4499 <a name="i_or">'<tt>or</tt>' Instruction</a>
4500</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4501
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4502<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4503
4504<h5>Syntax:</h5>
4505<pre>
4506 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4507</pre>
4508
4509<h5>Overview:</h5>
4510<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4511 two operands.</p>
4512
4513<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4514<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4515 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4516 values. Both arguments must have identical types.</p>
4517
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4518<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4519<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4520
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4521<table border="1" cellspacing="0" cellpadding="4">
4522 <tbody>
4523 <tr>
Bill Wendling4517fe52011-12-09 22:41:40 +0000[diff] [blame]4524 <th>In0</th>
4525 <th>In1</th>
4526 <th>Out</th>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4527 </tr>
4528 <tr>
4529 <td>0</td>
4530 <td>0</td>
4531 <td>0</td>
4532 </tr>
4533 <tr>
4534 <td>0</td>
4535 <td>1</td>
4536 <td>1</td>
4537 </tr>
4538 <tr>
4539 <td>1</td>
4540 <td>0</td>
4541 <td>1</td>
4542 </tr>
4543 <tr>
4544 <td>1</td>
4545 <td>1</td>
4546 <td>1</td>
4547 </tr>
4548 </tbody>
4549</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4550
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4551<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4552<pre>
4553 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4554 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4555 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4556</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4557
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4558</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4559
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4560<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4561<h4>
4562 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4563</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4564
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4565<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4566
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4567<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4568<pre>
4569 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4570</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4571
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4572<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4573<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4574 its two operands. The <tt>xor</tt> is used to implement the "one's
4575 complement" operation, which is the "~" operator in C.</p>
4576
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4577<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4578<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4579 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4580 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4581
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4582<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4583<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4584
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4585<table border="1" cellspacing="0" cellpadding="4">
4586 <tbody>
4587 <tr>
Bill Wendling4517fe52011-12-09 22:41:40 +0000[diff] [blame]4588 <th>In0</th>
4589 <th>In1</th>
4590 <th>Out</th>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4591 </tr>
4592 <tr>
4593 <td>0</td>
4594 <td>0</td>
4595 <td>0</td>
4596 </tr>
4597 <tr>
4598 <td>0</td>
4599 <td>1</td>
4600 <td>1</td>
4601 </tr>
4602 <tr>
4603 <td>1</td>
4604 <td>0</td>
4605 <td>1</td>
4606 </tr>
4607 <tr>
4608 <td>1</td>
4609 <td>1</td>
4610 <td>0</td>
4611 </tr>
4612 </tbody>
4613</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4614
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4615<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4616<pre>
4617 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4618 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4619 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4620 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4621</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4622
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4623</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4624
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4625</div>
4626
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4627<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4628<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4629 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4630</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4631
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4632<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4633
4634<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4635 target-independent manner. These instructions cover the element-access and
4636 vector-specific operations needed to process vectors effectively. While LLVM
4637 does directly support these vector operations, many sophisticated algorithms
4638 will want to use target-specific intrinsics to take full advantage of a
4639 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4640
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4641<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4642<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4643 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4644</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4645
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4646<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4647
4648<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4649<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4650 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4651</pre>
4652
4653<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4654<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4655 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4656
4657
4658<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4659<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4660 of <a href="#t_vector">vector</a> type. The second operand is an index
4661 indicating the position from which to extract the element. The index may be
4662 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4663
4664<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4665<p>The result is a scalar of the same type as the element type of
4666 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4667 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4668 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4669
4670<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4671<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4672 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4673</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4674
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4675</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4676
4677<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4678<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4679 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4680</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4681
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4682<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4683
4684<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4685<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4686 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4687</pre>
4688
4689<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4690<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4691 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4692
4693<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4694<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4695 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4696 whose type must equal the element type of the first operand. The third
4697 operand is an index indicating the position at which to insert the value.
4698 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4699
4700<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4701<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4702 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4703 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4704 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4705
4706<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4707<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4708 &lt;result&gt; = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4709</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4710
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4711</div>
4712
4713<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4714<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4715 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4716</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4717
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4718<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4719
4720<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4721<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4722 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4723</pre>
4724
4725<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4726<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4727 from two input vectors, returning a vector with the same element type as the
4728 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4729
4730<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4731<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4732 with types that match each other. The third argument is a shuffle mask whose
4733 element type is always 'i32'. The result of the instruction is a vector
4734 whose length is the same as the shuffle mask and whose element type is the
4735 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4736
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4737<p>The shuffle mask operand is required to be a constant vector with either
4738 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4739
4740<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4741<p>The elements of the two input vectors are numbered from left to right across
4742 both of the vectors. The shuffle mask operand specifies, for each element of
4743 the result vector, which element of the two input vectors the result element
4744 gets. The element selector may be undef (meaning "don't care") and the
4745 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4746
4747<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4748<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4749 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4750 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4751 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4752 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4753 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4754 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4755 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4756 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4757</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4758
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4759</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4760
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4761</div>
4762
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4763<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4764<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4765 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4766</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4767
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4768<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4769
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4770<p>LLVM supports several instructions for working with
4771 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4772
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4773<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4774<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4775 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4776</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4777
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4778<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4779
4780<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4781<pre>
4782 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4783</pre>
4784
4785<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4786<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4787 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4788
4789<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4790<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4791 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4792 <a href="#t_array">array</a> type. The operands are constant indices to
4793 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4794 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4795 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4796 <ul>
4797 <li>Since the value being indexed is not a pointer, the first index is
4798 omitted and assumed to be zero.</li>
4799 <li>At least one index must be specified.</li>
4800 <li>Not only struct indices but also array indices must be in
4801 bounds.</li>
4802 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4803
4804<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4805<p>The result is the value at the position in the aggregate specified by the
4806 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4807
4808<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4809<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4810 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4811</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4812
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4813</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4814
4815<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4816<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4817 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4818</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4819
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4820<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4821
4822<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4823<pre>
Bill Wendlingf6a91cf2011-07-26 20:42:28 +0000[diff] [blame]4824 &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 Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4825</pre>
4826
4827<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4828<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4829 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4830
4831<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4832<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4833 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4834 <a href="#t_array">array</a> type. The second operand is a first-class
4835 value to insert. The following operands are constant indices indicating
4836 the position at which to insert the value in a similar manner as indices in a
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4837 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4838 value to insert must have the same type as the value identified by the
4839 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4840
4841<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4842<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4843 that of <tt>val</tt> except that the value at the position specified by the
4844 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4845
4846<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4847<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4848 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4849 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4850 %agg3 = insertvalue {i32, {float}} %agg1, float %val, 1, 0 <i>; yields {i32 1, float %val}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4851</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4852
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4853</div>
4854
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4855</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4856
4857<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4858<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4859 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4860</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4861
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4862<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4863
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4864<p>A key design point of an SSA-based representation is how it represents
4865 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4866 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4867 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4868
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4869<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4870<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4871 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4872</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4873
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4874<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4875
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4876<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4877<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4878 &lt;result&gt; = alloca &lt;type&gt;[, &lt;ty&gt; &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4879</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4880
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4881<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4882<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4883 currently executing function, to be automatically released when this function
4884 returns to its caller. The object is always allocated in the generic address
4885 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4886
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4887<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4888<p>The '<tt>alloca</tt>' instruction
4889 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4890 runtime stack, returning a pointer of the appropriate type to the program.
4891 If "NumElements" is specified, it is the number of elements allocated,
4892 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4893 specified, the value result of the allocation is guaranteed to be aligned to
4894 at least that boundary. If not specified, or if zero, the target can choose
4895 to align the allocation on any convenient boundary compatible with the
4896 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4897
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4898<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4899
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4900<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4901<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4902 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4903 memory is automatically released when the function returns. The
4904 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4905 variables that must have an address available. When the function returns
4906 (either with the <tt><a href="#i_ret">ret</a></tt>
Bill Wendling3f6a3a22012-02-06 21:57:33 +0000[diff] [blame]4907 or <tt><a href="#i_resume">resume</a></tt> instructions), the memory is
Nick Lewyckyefe5e2e2012-02-29 08:26:44 +0000[diff] [blame]4908 reclaimed. Allocating zero bytes is legal, but the result is undefined.
4909 The order in which memory is allocated (ie., which way the stack grows) is
Nick Lewyckyf70a2bd2012-03-18 09:35:50 +0000[diff] [blame]4910 not specified.</p>
Nick Lewyckyefe5e2e2012-02-29 08:26:44 +0000[diff] [blame]4911
4912<p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4913
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4914<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4915<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4916 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4917 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4918 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4919 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4920</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4921
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4922</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4923
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4924<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4925<h4>
4926 <a name="i_load">'<tt>load</tt>' Instruction</a>
4927</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4928
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4929<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4930
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4931<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4932<pre>
Pete Cooper13e082d2012-02-10 18:13:54 +0000[diff] [blame]4933 &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 Friedman02e737b2011-08-12 22:50:01 +0000[diff] [blame]4934 &lt;result&gt; = load atomic [volatile] &lt;ty&gt;* &lt;pointer&gt; [singlethread] &lt;ordering&gt;, align &lt;alignment&gt;
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4935 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4936</pre>
4937
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4938<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4939<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4940
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4941<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4942<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4943 from which to load. The pointer must point to
4944 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4945 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4946 number or order of execution of this <tt>load</tt> with other <a
4947 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4948
Eli Friedman59b66882011-08-09 23:02:53 +0000[diff] [blame]4949<p>If the <code>load</code> is marked as <code>atomic</code>, it takes an extra
4950 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
4951 argument. The <code>release</code> and <code>acq_rel</code> orderings are
4952 not valid on <code>load</code> instructions. Atomic loads produce <a
4953 href="#memorymodel">defined</a> results when they may see multiple atomic
4954 stores. The type of the pointee must be an integer type whose bit width
4955 is a power of two greater than or equal to eight and less than or equal
4956 to a target-specific size limit. <code>align</code> must be explicitly
4957 specified on atomic loads, and the load has undefined behavior if the
4958 alignment is not set to a value which is at least the size in bytes of
4959 the pointee. <code>!nontemporal</code> does not have any defined semantics
4960 for atomic loads.</p>
4961
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4962<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4963 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4964 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4965 alignment for the target. It is the responsibility of the code emitter to
4966 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4967 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4968 produce less efficient code. An alignment of 1 is always safe.</p>
4969
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4970<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4971 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4972 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4973 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4974 and code generator that this load is not expected to be reused in the cache.
4975 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4976 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4977
Pete Cooper13e082d2012-02-10 18:13:54 +0000[diff] [blame]4978<p>The optional <tt>!invariant.load</tt> metadata must reference a single
4979 metatadata name &lt;index&gt; corresponding to a metadata node with no
4980 entries. The existence of the <tt>!invariant.load</tt> metatadata on the
4981 instruction tells the optimizer and code generator that this load address
4982 points to memory which does not change value during program execution.
4983 The optimizer may then move this load around, for example, by hoisting it
4984 out of loops using loop invariant code motion.</p>
4985
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4986<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4987<p>The location of memory pointed to is loaded. If the value being loaded is of
4988 scalar type then the number of bytes read does not exceed the minimum number
4989 of bytes needed to hold all bits of the type. For example, loading an
4990 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4991 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4992 is undefined if the value was not originally written using a store of the
4993 same type.</p>
4994
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4995<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4996<pre>
4997 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4998 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4999 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5000</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5001
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5002</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5003
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5004<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5005<h4>
5006 <a name="i_store">'<tt>store</tt>' Instruction</a>
5007</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5008
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5009<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5010
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5011<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5012<pre>
Bill Wendling4517fe52011-12-09 22:41:40 +0000[diff] [blame]5013 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>
5014 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 Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5015</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5016
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5017<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5018<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5019
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5020<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5021<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
5022 and an address at which to store it. The type of the
5023 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
5024 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]5025 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
5026 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
5027 order of execution of this <tt>store</tt> with other <a
5028 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5029
Eli Friedman59b66882011-08-09 23:02:53 +0000[diff] [blame]5030<p>If the <code>store</code> is marked as <code>atomic</code>, it takes an extra
5031 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
5032 argument. The <code>acquire</code> and <code>acq_rel</code> orderings aren't
5033 valid on <code>store</code> instructions. Atomic loads produce <a
5034 href="#memorymodel">defined</a> results when they may see multiple atomic
5035 stores. The type of the pointee must be an integer type whose bit width
5036 is a power of two greater than or equal to eight and less than or equal
5037 to a target-specific size limit. <code>align</code> must be explicitly
5038 specified on atomic stores, and the store has undefined behavior if the
5039 alignment is not set to a value which is at least the size in bytes of
5040 the pointee. <code>!nontemporal</code> does not have any defined semantics
5041 for atomic stores.</p>
5042
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5043<p>The optional constant "align" argument specifies the alignment of the
5044 operation (that is, the alignment of the memory address). A value of 0 or an
5045 omitted "align" argument means that the operation has the preferential
5046 alignment for the target. It is the responsibility of the code emitter to
5047 ensure that the alignment information is correct. Overestimating the
5048 alignment results in an undefined behavior. Underestimating the alignment may
5049 produce less efficient code. An alignment of 1 is always safe.</p>
5050
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]5051<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5052 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5053 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]5054 instruction tells the optimizer and code generator that this load is
5055 not expected to be reused in the cache. The code generator may
5056 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5057 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]5058
5059
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5060<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5061<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
5062 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
5063 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
5064 does not exceed the minimum number of bytes needed to hold all bits of the
5065 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
5066 writing a value of a type like <tt>i20</tt> with a size that is not an
5067 integral number of bytes, it is unspecified what happens to the extra bits
5068 that do not belong to the type, but they will typically be overwritten.</p>
5069
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5070<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5071<pre>
5072 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]5073 store i32 3, i32* %ptr <i>; yields {void}</i>
5074 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5075</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5076
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]5077</div>
5078
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]5079<!-- _______________________________________________________________________ -->
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]5080<h4>
5081<a name="i_fence">'<tt>fence</tt>' Instruction</a>
5082</h4>
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]5083
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]5084<div>
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]5085
5086<h5>Syntax:</h5>
5087<pre>
5088 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
5089</pre>
5090
5091<h5>Overview:</h5>
5092<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
5093between operations.</p>
5094
5095<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
5096href="#ordering">ordering</a> argument which defines what
5097<i>synchronizes-with</i> edges they add. They can only be given
5098<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
5099<code>seq_cst</code> orderings.</p>
5100
5101<h5>Semantics:</h5>
5102<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
5103semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
5104<code>acquire</code> ordering semantics if and only if there exist atomic
5105operations <var>X</var> and <var>Y</var>, both operating on some atomic object
5106<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
5107<var>X</var> modifies <var>M</var> (either directly or through some side effect
5108of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
5109<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
5110<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
5111than an explicit <code>fence</code>, one (but not both) of the atomic operations
5112<var>X</var> or <var>Y</var> might provide a <code>release</code> or
5113<code>acquire</code> (resp.) ordering constraint and still
5114<i>synchronize-with</i> the explicit <code>fence</code> and establish the
5115<i>happens-before</i> edge.</p>
5116
5117<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
5118having both <code>acquire</code> and <code>release</code> semantics specified
5119above, participates in the global program order of other <code>seq_cst</code>
5120operations and/or fences.</p>
5121
5122<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
5123specifies that the fence only synchronizes with other fences in the same
5124thread. (This is useful for interacting with signal handlers.)</p>
5125
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]5126<h5>Example:</h5>
5127<pre>
5128 fence acquire <i>; yields {void}</i>
5129 fence singlethread seq_cst <i>; yields {void}</i>
5130</pre>
5131
5132</div>
5133
5134<!-- _______________________________________________________________________ -->
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]5135<h4>
5136<a name="i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a>
5137</h4>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]5138
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]5139<div>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]5140
5141<h5>Syntax:</h5>
5142<pre>
Bill Wendling4517fe52011-12-09 22:41:40 +0000[diff] [blame]5143 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 Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]5144</pre>
5145
5146<h5>Overview:</h5>
5147<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
5148It loads a value in memory and compares it to a given value. If they are
5149equal, it stores a new value into the memory.</p>
5150
5151<h5>Arguments:</h5>
5152<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
5153address to operate on, a value to compare to the value currently be at that
5154address, and a new value to place at that address if the compared values are
5155equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
5156bit width is a power of two greater than or equal to eight and less than
5157or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
5158'<var>&lt;new&gt;</var>' must have the same type, and the type of
5159'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
5160<code>cmpxchg</code> is marked as <code>volatile</code>, then the
5161optimizer is not allowed to modify the number or order of execution
5162of this <code>cmpxchg</code> with other <a href="#volatile">volatile
5163operations</a>.</p>
5164
5165<!-- FIXME: Extend allowed types. -->
5166
5167<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
5168<code>cmpxchg</code> synchronizes with other atomic operations.</p>
5169
5170<p>The optional "<code>singlethread</code>" argument declares that the
5171<code>cmpxchg</code> is only atomic with respect to code (usually signal
5172handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
5173cmpxchg is atomic with respect to all other code in the system.</p>
5174
5175<p>The pointer passed into cmpxchg must have alignment greater than or equal to
5176the size in memory of the operand.
5177
5178<h5>Semantics:</h5>
5179<p>The contents of memory at the location specified by the
5180'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
5181'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
5182'<tt>&lt;new&gt;</tt>' is written. The original value at the location
5183is returned.
5184
5185<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
5186purpose of identifying <a href="#release_sequence">release sequences</a>. A
5187failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
5188parameter determined by dropping any <code>release</code> part of the
5189<code>cmpxchg</code>'s ordering.</p>
5190
5191<!--
5192FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
5193optimization work on ARM.)
5194
5195FIXME: Is a weaker ordering constraint on failure helpful in practice?
5196-->
5197
5198<h5>Example:</h5>
5199<pre>
5200entry:
Bill Wendling4517fe52011-12-09 22:41:40 +0000[diff] [blame]5201 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]5202 <a href="#i_br">br</a> label %loop
5203
5204loop:
5205 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
5206 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
Bill Wendling4517fe52011-12-09 22:41:40 +0000[diff] [blame]5207 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]5208 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
5209 <a href="#i_br">br</a> i1 %success, label %done, label %loop
5210
5211done:
5212 ...
5213</pre>
5214
5215</div>
5216
5217<!-- _______________________________________________________________________ -->
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]5218<h4>
5219<a name="i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a>
5220</h4>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]5221
NAKAMURA Takumi0300d882011-08-12 06:17:17 +0000[diff] [blame]5222<div>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]5223
5224<h5>Syntax:</h5>
5225<pre>
Eli Friedman02e737b2011-08-12 22:50:01 +0000[diff] [blame]5226 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 Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]5227</pre>
5228
5229<h5>Overview:</h5>
5230<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
5231
5232<h5>Arguments:</h5>
5233<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
5234operation to apply, an address whose value to modify, an argument to the
5235operation. The operation must be one of the following keywords:</p>
5236<ul>
5237 <li>xchg</li>
5238 <li>add</li>
5239 <li>sub</li>
5240 <li>and</li>
5241 <li>nand</li>
5242 <li>or</li>
5243 <li>xor</li>
5244 <li>max</li>
5245 <li>min</li>
5246 <li>umax</li>
5247 <li>umin</li>
5248</ul>
5249
5250<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
5251bit width is a power of two greater than or equal to eight and less than
5252or equal to a target-specific size limit. The type of the
5253'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
5254If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
5255optimizer is not allowed to modify the number or order of execution of this
5256<code>atomicrmw</code> with other <a href="#volatile">volatile
5257 operations</a>.</p>
5258
5259<!-- FIXME: Extend allowed types. -->
5260
5261<h5>Semantics:</h5>
5262<p>The contents of memory at the location specified by the
5263'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
5264back. The original value at the location is returned. The modification is
5265specified by the <var>operation</var> argument:</p>
5266
5267<ul>
5268 <li>xchg: <code>*ptr = val</code></li>
5269 <li>add: <code>*ptr = *ptr + val</code></li>
5270 <li>sub: <code>*ptr = *ptr - val</code></li>
5271 <li>and: <code>*ptr = *ptr &amp; val</code></li>
5272 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
5273 <li>or: <code>*ptr = *ptr | val</code></li>
5274 <li>xor: <code>*ptr = *ptr ^ val</code></li>
5275 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
5276 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
5277 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
5278 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
5279</ul>
5280
5281<h5>Example:</h5>
5282<pre>
5283 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
5284</pre>
5285
5286</div>
5287
5288<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5289<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5290 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5291</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5292
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5293<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5294
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]5295<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5296<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]5297 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]5298 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5299 &lt;result&gt; = getelementptr &lt;ptr vector&gt; ptrval, &lt;vector index type&gt; idx
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5300</pre>
5301
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]5302<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5303<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]5304 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
5305 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5306
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]5307<h5>Arguments:</h5>
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5308<p>The first argument is always a pointer or a vector of pointers,
5309 and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]5310 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5311 elements of the aggregate object are indexed. The interpretation of each
5312 index is dependent on the type being indexed into. The first index always
5313 indexes the pointer value given as the first argument, the second index
5314 indexes a value of the type pointed to (not necessarily the value directly
5315 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]5316 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]5317 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]5318 can never be pointers, since that would require loading the pointer before
5319 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]5320
5321<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]5322 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]5323 integer <b>constants</b> are allowed. When indexing into an array, pointer
5324 or vector, integers of any width are allowed, and they are not required to be
Eli Friedmand8874dc2011-08-12 23:37:55 +0000[diff] [blame]5325 constant. These integers are treated as signed values where relevant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5326
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5327<p>For example, let's consider a C code fragment and how it gets compiled to
5328 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5329
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5330<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5331struct RT {
5332 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]5333 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5334 char C;
5335};
5336struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]5337 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5338 double Y;
5339 struct RT Z;
5340};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5341
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]5342int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5343 return &amp;s[1].Z.B[5][13];
5344}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5345</pre>
5346
Bill Wendling7ad1f362011-12-13 01:07:07 +0000[diff] [blame]5347<p>The LLVM code generated by Clang is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5348
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5349<pre class="doc_code">
Bill Wendling7ad1f362011-12-13 01:07:07 +0000[diff] [blame]5350%struct.RT = <a href="#namedtypes">type</a> { i8, [10 x [20 x i32]], i8 }
5351%struct.ST = <a href="#namedtypes">type</a> { i32, double, %struct.RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5352
Bill Wendling7ad1f362011-12-13 01:07:07 +0000[diff] [blame]5353define i32* @foo(%struct.ST* %s) nounwind uwtable readnone optsize ssp {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5354entry:
Bill Wendling7ad1f362011-12-13 01:07:07 +0000[diff] [blame]5355 %arrayidx = getelementptr inbounds %struct.ST* %s, i64 1, i32 2, i32 1, i64 5, i64 13
5356 ret i32* %arrayidx
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5357}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5358</pre>
5359
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]5360<h5>Semantics:</h5>
Bill Wendling7ad1f362011-12-13 01:07:07 +0000[diff] [blame]5361<p>In the example above, the first index is indexing into the
5362 '<tt>%struct.ST*</tt>' type, which is a pointer, yielding a
5363 '<tt>%struct.ST</tt>' = '<tt>{ i32, double, %struct.RT }</tt>' type, a
5364 structure. The second index indexes into the third element of the structure,
5365 yielding a '<tt>%struct.RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]], i8 }</tt>'
5366 type, another structure. The third index indexes into the second element of
5367 the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an array. The
5368 two dimensions of the array are subscripted into, yielding an '<tt>i32</tt>'
5369 type. The '<tt>getelementptr</tt>' instruction returns a pointer to this
5370 element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5371
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5372<p>Note that it is perfectly legal to index partially through a structure,
5373 returning a pointer to an inner element. Because of this, the LLVM code for
5374 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5375
Bill Wendling7ad1f362011-12-13 01:07:07 +0000[diff] [blame]5376<pre class="doc_code">
5377define i32* @foo(%struct.ST* %s) {
5378 %t1 = getelementptr %struct.ST* %s, i32 1 <i>; yields %struct.ST*:%t1</i>
5379 %t2 = getelementptr %struct.ST* %t1, i32 0, i32 2 <i>; yields %struct.RT*:%t2</i>
5380 %t3 = getelementptr %struct.RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
5381 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
5382 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
5383 ret i32* %t5
5384}
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5385</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]5386
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]5387<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman9a2a0932011-12-06 03:18:47 +0000[diff] [blame]5388 <tt>getelementptr</tt> is a <a href="#poisonvalues">poison value</a> if the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]5389 base pointer is not an <i>in bounds</i> address of an allocated object,
5390 or if any of the addresses that would be formed by successive addition of
5391 the offsets implied by the indices to the base address with infinitely
Eli Friedmand8874dc2011-08-12 23:37:55 +0000[diff] [blame]5392 precise signed arithmetic are not an <i>in bounds</i> address of that
5393 allocated object. The <i>in bounds</i> addresses for an allocated object
5394 are all the addresses that point into the object, plus the address one
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5395 byte past the end.
5396 In cases where the base is a vector of pointers the <tt>inbounds</tt> keyword
5397 applies to each of the computations element-wise. </p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]5398
5399<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
Eli Friedmand8874dc2011-08-12 23:37:55 +0000[diff] [blame]5400 the base address with silently-wrapping two's complement arithmetic. If the
5401 offsets have a different width from the pointer, they are sign-extended or
5402 truncated to the width of the pointer. The result value of the
5403 <tt>getelementptr</tt> may be outside the object pointed to by the base
5404 pointer. The result value may not necessarily be used to access memory
5405 though, even if it happens to point into allocated storage. See the
5406 <a href="#pointeraliasing">Pointer Aliasing Rules</a> section for more
5407 information.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]5408
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5409<p>The getelementptr instruction is often confusing. For some more insight into
5410 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]5411
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]5412<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5413<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5414 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]5415 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
5416 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5417 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]5418 <i>; yields i8*:eptr</i>
5419 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]5420 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]5421 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5422</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5423
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5424<p>In cases where the pointer argument is a vector of pointers, only a
5425 single index may be used, and the number of vector elements has to be
5426 the same. For example: </p>
5427<pre class="doc_code">
5428 %A = getelementptr <4 x i8*> %ptrs, <4 x i64> %offsets,
5429</pre>
5430
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5431</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]5432
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5433</div>
5434
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5435<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5436<h3>
5437 <a name="convertops">Conversion Operations</a>
5438</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5439
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5440<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5441
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5442<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5443 which all take a single operand and a type. They perform various bit
5444 conversions on the operand.</p>
5445
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5446<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5447<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5448 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5449</h4>
5450
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5451<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5452
5453<h5>Syntax:</h5>
5454<pre>
5455 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5456</pre>
5457
5458<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5459<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5460 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5461
5462<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5463<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5464 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5465 of the same number of integers.
5466 The bit size of the <tt>value</tt> must be larger than
5467 the bit size of the destination type, <tt>ty2</tt>.
5468 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5469
5470<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5471<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5472 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5473 source size must be larger than the destination size, <tt>trunc</tt> cannot
5474 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5475
5476<h5>Example:</h5>
5477<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5478 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5479 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5480 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5481 %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 Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5482</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5483
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5484</div>
5485
5486<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5487<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5488 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5489</h4>
5490
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5491<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5492
5493<h5>Syntax:</h5>
5494<pre>
5495 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5496</pre>
5497
5498<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5499<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5500 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5501
5502
5503<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5504<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5505 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5506 of the same number of integers.
5507 The bit size of the <tt>value</tt> must be smaller than
5508 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5509 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5510
5511<h5>Semantics:</h5>
5512<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5513 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5514
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]5515<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5516
5517<h5>Example:</h5>
5518<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5519 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5520 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5521 %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 Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5522</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5523
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5524</div>
5525
5526<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5527<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5528 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5529</h4>
5530
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5531<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5532
5533<h5>Syntax:</h5>
5534<pre>
5535 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5536</pre>
5537
5538<h5>Overview:</h5>
5539<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5540
5541<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5542<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5543 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5544 of the same number of integers.
5545 The bit size of the <tt>value</tt> must be smaller than
5546 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5547 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5548
5549<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5550<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5551 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5552 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5553
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5554<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5555
5556<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5557<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5558 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5559 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5560 %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 Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5561</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5562
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5563</div>
5564
5565<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5566<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5567 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5568</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5569
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5570<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5571
5572<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5573<pre>
5574 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5575</pre>
5576
5577<h5>Overview:</h5>
5578<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5579 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5580
5581<h5>Arguments:</h5>
5582<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5583 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5584 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5585 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5586 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5587
5588<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5589<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5590 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5591 <a href="#t_floating">floating point</a> type. If the value cannot fit
5592 within the destination type, <tt>ty2</tt>, then the results are
5593 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5594
5595<h5>Example:</h5>
5596<pre>
5597 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5598 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5599</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5600
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5601</div>
5602
5603<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5604<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5605 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5606</h4>
5607
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5608<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5609
5610<h5>Syntax:</h5>
5611<pre>
5612 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5613</pre>
5614
5615<h5>Overview:</h5>
5616<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5617 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5618
5619<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5620<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5621 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5622 a <a href="#t_floating">floating point</a> type to cast it to. The source
5623 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5624
5625<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5626<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5627 <a href="#t_floating">floating point</a> type to a larger
5628 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5629 used to make a <i>no-op cast</i> because it always changes bits. Use
5630 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5631
5632<h5>Example:</h5>
5633<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]5634 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5635 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5636</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5637
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5638</div>
5639
5640<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5641<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]5642 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5643</h4>
5644
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5645<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5646
5647<h5>Syntax:</h5>
5648<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5649 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5650</pre>
5651
5652<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5653<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5654 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5655
5656<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5657<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5658 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5659 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5660 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5661 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5662
5663<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5664<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5665 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5666 towards zero) unsigned integer value. If the value cannot fit
5667 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5668
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5669<h5>Example:</h5>
5670<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5671 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5672 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5673 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5674</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5675
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5676</div>
5677
5678<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5679<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5680 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5681</h4>
5682
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5683<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5684
5685<h5>Syntax:</h5>
5686<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5687 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5688</pre>
5689
5690<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5691<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5692 <a href="#t_floating">floating point</a> <tt>value</tt> to
5693 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5694
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5695<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5696<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5697 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5698 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5699 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5700 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5701
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5702<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5703<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5704 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5705 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5706 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5707
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5708<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5709<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5710 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5711 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5712 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5713</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5714
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5715</div>
5716
5717<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5718<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5719 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5720</h4>
5721
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5722<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5723
5724<h5>Syntax:</h5>
5725<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5726 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5727</pre>
5728
5729<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5730<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5731 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5732
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5733<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5734<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5735 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5736 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5737 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5738 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5739
5740<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5741<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5742 integer quantity and converts it to the corresponding floating point
5743 value. If the value cannot fit in the floating point value, the results are
5744 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5745
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5746<h5>Example:</h5>
5747<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5748 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5749 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5750</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5751
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5752</div>
5753
5754<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5755<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5756 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5757</h4>
5758
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5759<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5760
5761<h5>Syntax:</h5>
5762<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5763 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5764</pre>
5765
5766<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5767<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5768 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5769
5770<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5771<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5772 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5773 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5774 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5775 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5776
5777<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5778<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5779 quantity and converts it to the corresponding floating point value. If the
5780 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5781
5782<h5>Example:</h5>
5783<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5784 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5785 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5786</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5787
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5788</div>
5789
5790<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5791<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5792 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5793</h4>
5794
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5795<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5796
5797<h5>Syntax:</h5>
5798<pre>
5799 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5800</pre>
5801
5802<h5>Overview:</h5>
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5803<p>The '<tt>ptrtoint</tt>' instruction converts the pointer or a vector of
5804 pointers <tt>value</tt> to
5805 the integer (or vector of integers) type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5806
5807<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5808<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5809 must be a a value of type <a href="#t_pointer">pointer</a> or a vector of
5810 pointers, and a type to cast it to
5811 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> or a vector
5812 of integers type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5813
5814<h5>Semantics:</h5>
5815<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5816 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5817 truncating or zero extending that value to the size of the integer type. If
5818 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5819 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5820 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5821 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5822
5823<h5>Example:</h5>
5824<pre>
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5825 %X = ptrtoint i32* %P to i8 <i>; yields truncation on 32-bit architecture</i>
5826 %Y = ptrtoint i32* %P to i64 <i>; yields zero extension on 32-bit architecture</i>
5827 %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 Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5828</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5829
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5830</div>
5831
5832<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5833<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5834 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5835</h4>
5836
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5837<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5838
5839<h5>Syntax:</h5>
5840<pre>
5841 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5842</pre>
5843
5844<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5845<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5846 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5847
5848<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5849<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5850 value to cast, and a type to cast it to, which must be a
5851 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5852
5853<h5>Semantics:</h5>
5854<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5855 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5856 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5857 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5858 than the size of a pointer then a zero extension is done. If they are the
5859 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5860
5861<h5>Example:</h5>
5862<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5863 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5864 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5865 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5866 %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 Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5867</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5868
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5869</div>
5870
5871<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5872<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5873 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5874</h4>
5875
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5876<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5877
5878<h5>Syntax:</h5>
5879<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5880 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5881</pre>
5882
5883<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5884<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5885 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5886
5887<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5888<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5889 non-aggregate first class value, and a type to cast it to, which must also be
5890 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5891 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5892 identical. If the source type is a pointer, the destination type must also be
5893 a pointer. This instruction supports bitwise conversion of vectors to
5894 integers and to vectors of other types (as long as they have the same
5895 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5896
5897<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5898<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5899 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5900 this conversion. The conversion is done as if the <tt>value</tt> had been
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5901 stored to memory and read back as type <tt>ty2</tt>.
5902 Pointer (or vector of pointers) types may only be converted to other pointer
5903 (or vector of pointers) types with this instruction. To convert
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5904 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5905 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5906
5907<h5>Example:</h5>
5908<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5909 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5910 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5911 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
5912 %Z = bitcast &lt;2 x i32*&gt; %V to &lt;2 x i64*&gt; <i>; yields &lt;2 x i64*&gt;</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5913</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5914
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5915</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5916
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5917</div>
5918
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5919<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5920<h3>
5921 <a name="otherops">Other Operations</a>
5922</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5923
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5924<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5925
5926<p>The instructions in this category are the "miscellaneous" instructions, which
5927 defy better classification.</p>
5928
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5929<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5930<h4>
5931 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5932</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5933
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5934<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5935
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5936<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5937<pre>
5938 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5939</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5940
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5941<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5942<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
Nadav Rotem3924cb02011-12-05 06:29:09 +0000[diff] [blame]5943 boolean values based on comparison of its two integer, integer vector,
5944 pointer, or pointer vector operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5945
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5946<h5>Arguments:</h5>
5947<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5948 the condition code indicating the kind of comparison to perform. It is not a
5949 value, just a keyword. The possible condition code are:</p>
5950
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5951<ol>
5952 <li><tt>eq</tt>: equal</li>
5953 <li><tt>ne</tt>: not equal </li>
5954 <li><tt>ugt</tt>: unsigned greater than</li>
5955 <li><tt>uge</tt>: unsigned greater or equal</li>
5956 <li><tt>ult</tt>: unsigned less than</li>
5957 <li><tt>ule</tt>: unsigned less or equal</li>
5958 <li><tt>sgt</tt>: signed greater than</li>
5959 <li><tt>sge</tt>: signed greater or equal</li>
5960 <li><tt>slt</tt>: signed less than</li>
5961 <li><tt>sle</tt>: signed less or equal</li>
5962</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5963
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5964<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5965 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5966 typed. They must also be identical types.</p>
5967
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5968<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5969<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5970 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5971 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5972 result, as follows:</p>
5973
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5974<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5975 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5976 <tt>false</tt> otherwise. No sign interpretation is necessary or
5977 performed.</li>
5978
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5979 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5980 <tt>false</tt> otherwise. No sign interpretation is necessary or
5981 performed.</li>
5982
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5983 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5984 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5985
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5986 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5987 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5988 to <tt>op2</tt>.</li>
5989
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5990 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5991 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5992
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5993 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5994 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5995
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5996 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5997 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5998
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5999 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6000 <tt>true</tt> if <tt>op1</tt> is greater than or equal
6001 to <tt>op2</tt>.</li>
6002
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6003 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6004 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
6005
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6006 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6007 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6008</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6009
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6010<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6011 values are compared as if they were integers.</p>
6012
6013<p>If the operands are integer vectors, then they are compared element by
6014 element. The result is an <tt>i1</tt> vector with the same number of elements
6015 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6016
6017<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6018<pre>
6019 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]6020 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
6021 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
6022 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
6023 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
6024 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6025</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]6026
6027<p>Note that the code generator does not yet support vector types with
6028 the <tt>icmp</tt> instruction.</p>
6029
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6030</div>
6031
6032<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6033<h4>
6034 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
6035</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6036
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6037<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6038
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6039<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6040<pre>
6041 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6042</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6043
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6044<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6045<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
6046 values based on comparison of its operands.</p>
6047
6048<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]6049(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6050
6051<p>If the operands are floating point vectors, then the result type is a vector
6052 of boolean with the same number of elements as the operands being
6053 compared.</p>
6054
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6055<h5>Arguments:</h5>
6056<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6057 the condition code indicating the kind of comparison to perform. It is not a
6058 value, just a keyword. The possible condition code are:</p>
6059
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6060<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]6061 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6062 <li><tt>oeq</tt>: ordered and equal</li>
6063 <li><tt>ogt</tt>: ordered and greater than </li>
6064 <li><tt>oge</tt>: ordered and greater than or equal</li>
6065 <li><tt>olt</tt>: ordered and less than </li>
6066 <li><tt>ole</tt>: ordered and less than or equal</li>
6067 <li><tt>one</tt>: ordered and not equal</li>
6068 <li><tt>ord</tt>: ordered (no nans)</li>
6069 <li><tt>ueq</tt>: unordered or equal</li>
6070 <li><tt>ugt</tt>: unordered or greater than </li>
6071 <li><tt>uge</tt>: unordered or greater than or equal</li>
6072 <li><tt>ult</tt>: unordered or less than </li>
6073 <li><tt>ule</tt>: unordered or less than or equal</li>
6074 <li><tt>une</tt>: unordered or not equal</li>
6075 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]6076 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6077</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6078
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6079<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6080 <i>unordered</i> means that either operand may be a QNAN.</p>
6081
6082<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
6083 a <a href="#t_floating">floating point</a> type or
6084 a <a href="#t_vector">vector</a> of floating point type. They must have
6085 identical types.</p>
6086
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6087<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]6088<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6089 according to the condition code given as <tt>cond</tt>. If the operands are
6090 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]6091 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6092 follows:</p>
6093
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6094<ol>
6095 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6096
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6097 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6098 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
6099
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]6100 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6101 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6102
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6103 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6104 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
6105
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6106 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6107 <tt>op1</tt> is less than <tt>op2</tt>.</li>
6108
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6109 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6110 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
6111
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6112 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6113 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
6114
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]6115 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6116
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6117 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6118 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
6119
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6120 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6121 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
6122
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6123 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6124 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
6125
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6126 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6127 <tt>op1</tt> is less than <tt>op2</tt>.</li>
6128
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6129 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6130 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
6131
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6132 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6133 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
6134
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]6135 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6136
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6137 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
6138</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6139
6140<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6141<pre>
6142 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]6143 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
6144 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
6145 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6146</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]6147
6148<p>Note that the code generator does not yet support vector types with
6149 the <tt>fcmp</tt> instruction.</p>
6150
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]6151</div>
6152
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]6153<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6154<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]6155 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6156</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]6157
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6158<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]6159
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]6160<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6161<pre>
6162 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
6163</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]6164
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]6165<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6166<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
6167 SSA graph representing the function.</p>
6168
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]6169<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6170<p>The type of the incoming values is specified with the first type field. After
6171 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
6172 one pair for each predecessor basic block of the current block. Only values
6173 of <a href="#t_firstclass">first class</a> type may be used as the value
6174 arguments to the PHI node. Only labels may be used as the label
6175 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]6176
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6177<p>There must be no non-phi instructions between the start of a basic block and
6178 the PHI instructions: i.e. PHI instructions must be first in a basic
6179 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]6180
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6181<p>For the purposes of the SSA form, the use of each incoming value is deemed to
6182 occur on the edge from the corresponding predecessor block to the current
6183 block (but after any definition of an '<tt>invoke</tt>' instruction's return
6184 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]6185
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]6186<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6187<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6188 specified by the pair corresponding to the predecessor basic block that
6189 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]6190
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]6191<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]6192<pre>
6193Loop: ; Infinite loop that counts from 0 on up...
6194 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
6195 %nextindvar = add i32 %indvar, 1
6196 br label %Loop
6197</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6198
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]6199</div>
6200
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6201<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6202<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6203 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6204</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6205
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6206<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6207
6208<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6209<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]6210 &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>
6211
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6212 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6213</pre>
6214
6215<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6216<p>The '<tt>select</tt>' instruction is used to choose one value based on a
6217 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6218
6219
6220<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6221<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
6222 values indicating the condition, and two values of the
6223 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
6224 vectors and the condition is a scalar, then entire vectors are selected, not
6225 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6226
6227<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6228<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
6229 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6230
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6231<p>If the condition is a vector of i1, then the value arguments must be vectors
6232 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6233
6234<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6235<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]6236 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6237</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]6238
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]6239</div>
6240
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]6241<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6242<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6243 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6244</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6245
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6246<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6247
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6248<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6249<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]6250 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6251</pre>
6252
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6253<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6254<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6255
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6256<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6257<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6258
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]6259<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]6260 <li>The optional "tail" marker indicates that the callee function does not
6261 access any allocas or varargs in the caller. Note that calls may be
6262 marked "tail" even if they do not occur before
6263 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
6264 present, the function call is eligible for tail call optimization,
6265 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]6266 optimized into a jump</a>. The code generator may optimize calls marked
6267 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
6268 sibling call optimization</a> when the caller and callee have
6269 matching signatures, or 2) forced tail call optimization when the
6270 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]6271 <ul>
6272 <li>Caller and callee both have the calling
6273 convention <tt>fastcc</tt>.</li>
6274 <li>The call is in tail position (ret immediately follows call and ret
6275 uses value of call or is void).</li>
6276 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]6277 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]6278 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
6279 constraints are met.</a></li>
6280 </ul>
6281 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]6282
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6283 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
6284 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]6285 defaults to using C calling conventions. The calling convention of the
6286 call must match the calling convention of the target function, or else the
6287 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]6288
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6289 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
6290 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
6291 '<tt>inreg</tt>' attributes are valid here.</li>
6292
6293 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
6294 type of the return value. Functions that return no value are marked
6295 <tt><a href="#t_void">void</a></tt>.</li>
6296
6297 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
6298 being invoked. The argument types must match the types implied by this
6299 signature. This type can be omitted if the function is not varargs and if
6300 the function type does not return a pointer to a function.</li>
6301
6302 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
6303 be invoked. In most cases, this is a direct function invocation, but
6304 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
6305 to function value.</li>
6306
6307 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]6308 signature argument types and parameter attributes. All arguments must be
6309 of <a href="#t_firstclass">first class</a> type. If the function
6310 signature indicates the function accepts a variable number of arguments,
6311 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6312
6313 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
6314 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
6315 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]6316</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6317
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6318<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6319<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
6320 a specified function, with its incoming arguments bound to the specified
6321 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
6322 function, control flow continues with the instruction after the function
6323 call, and the return value of the function is bound to the result
6324 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6325
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6326<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6327<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]6328 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6329 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]6330 %X = tail call i32 @foo() <i>; yields i32</i>
6331 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
6332 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]6333
6334 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]6335 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]6336 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
6337 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]6338 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]6339 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]6340</pre>
6341
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]6342<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]6343standard C99 library as being the C99 library functions, and may perform
6344optimizations or generate code for them under that assumption. This is
6345something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6346freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]6347
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6348</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6349
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6350<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6351<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]6352 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6353</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6354
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6355<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6356
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]6357<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6358<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6359 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6360</pre>
6361
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]6362<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6363<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6364 the "variable argument" area of a function call. It is used to implement the
6365 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6366
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]6367<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6368<p>This instruction takes a <tt>va_list*</tt> value and the type of the
6369 argument. It returns a value of the specified argument type and increments
6370 the <tt>va_list</tt> to point to the next argument. The actual type
6371 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6372
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]6373<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6374<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
6375 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
6376 to the next argument. For more information, see the variable argument
6377 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6378
6379<p>It is legal for this instruction to be called in a function which does not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6380 take a variable number of arguments, for example, the <tt>vfprintf</tt>
6381 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6382
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6383<p><tt>va_arg</tt> is an LLVM instruction instead of
6384 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
6385 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6386
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]6387<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]6388<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
6389
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6390<p>Note that the code generator does not yet fully support va_arg on many
6391 targets. Also, it does not currently support va_arg with aggregate types on
6392 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]6393
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6394</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6395
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6396<!-- _______________________________________________________________________ -->
6397<h4>
6398 <a name="i_landingpad">'<tt>landingpad</tt>' Instruction</a>
6399</h4>
6400
6401<div>
6402
6403<h5>Syntax:</h5>
6404<pre>
Duncan Sandsdf9d7812012-01-13 19:59:16 +0000[diff] [blame]6405 &lt;resultval&gt; = landingpad &lt;resultty&gt; personality &lt;type&gt; &lt;pers_fn&gt; &lt;clause&gt;+
6406 &lt;resultval&gt; = landingpad &lt;resultty&gt; personality &lt;type&gt; &lt;pers_fn&gt; cleanup &lt;clause&gt;*
Bill Wendling49bfb122011-08-08 08:06:05 +0000[diff] [blame]6407
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6408 &lt;clause&gt; := catch &lt;type&gt; &lt;value&gt;
Bill Wendlingfae14752011-08-12 20:24:12 +0000[diff] [blame]6409 &lt;clause&gt; := filter &lt;array constant type&gt; &lt;array constant&gt;
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6410</pre>
6411
6412<h5>Overview:</h5>
6413<p>The '<tt>landingpad</tt>' instruction is used by
6414 <a href="ExceptionHandling.html#overview">LLVM's exception handling
6415 system</a> to specify that a basic block is a landing pad &mdash; one where
6416 the exception lands, and corresponds to the code found in the
6417 <i><tt>catch</tt></i> portion of a <i><tt>try/catch</tt></i> sequence. It
6418 defines values supplied by the personality function (<tt>pers_fn</tt>) upon
6419 re-entry to the function. The <tt>resultval</tt> has the
Duncan Sandsdf9d7812012-01-13 19:59:16 +0000[diff] [blame]6420 type <tt>resultty</tt>.</p>
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6421
6422<h5>Arguments:</h5>
6423<p>This instruction takes a <tt>pers_fn</tt> value. This is the personality
6424 function associated with the unwinding mechanism. The optional
6425 <tt>cleanup</tt> flag indicates that the landing pad block is a cleanup.</p>
6426
6427<p>A <tt>clause</tt> begins with the clause type &mdash; <tt>catch</tt>
Bill Wendlingfae14752011-08-12 20:24:12 +0000[diff] [blame]6428 or <tt>filter</tt> &mdash; and contains the global variable representing the
6429 "type" that may be caught or filtered respectively. Unlike the
6430 <tt>catch</tt> clause, the <tt>filter</tt> clause takes an array constant as
6431 its argument. Use "<tt>[0 x i8**] undef</tt>" for a filter which cannot
6432 throw. The '<tt>landingpad</tt>' instruction must contain <em>at least</em>
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6433 one <tt>clause</tt> or the <tt>cleanup</tt> flag.</p>
6434
6435<h5>Semantics:</h5>
6436<p>The '<tt>landingpad</tt>' instruction defines the values which are set by the
6437 personality function (<tt>pers_fn</tt>) upon re-entry to the function, and
6438 therefore the "result type" of the <tt>landingpad</tt> instruction. As with
6439 calling conventions, how the personality function results are represented in
6440 LLVM IR is target specific.</p>
6441
Bill Wendling0524b8d2011-08-03 17:17:06 +0000[diff] [blame]6442<p>The clauses are applied in order from top to bottom. If two
6443 <tt>landingpad</tt> instructions are merged together through inlining, the
Duncan Sandsdf9d7812012-01-13 19:59:16 +0000[diff] [blame]6444 clauses from the calling function are appended to the list of clauses.
6445 When the call stack is being unwound due to an exception being thrown, the
6446 exception is compared against each <tt>clause</tt> in turn. If it doesn't
6447 match any of the clauses, and the <tt>cleanup</tt> flag is not set, then
6448 unwinding continues further up the call stack.</p>
Bill Wendling0524b8d2011-08-03 17:17:06 +0000[diff] [blame]6449
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6450<p>The <tt>landingpad</tt> instruction has several restrictions:</p>
6451
6452<ul>
6453 <li>A landing pad block is a basic block which is the unwind destination of an
6454 '<tt>invoke</tt>' instruction.</li>
6455 <li>A landing pad block must have a '<tt>landingpad</tt>' instruction as its
6456 first non-PHI instruction.</li>
6457 <li>There can be only one '<tt>landingpad</tt>' instruction within the landing
6458 pad block.</li>
6459 <li>A basic block that is not a landing pad block may not include a
6460 '<tt>landingpad</tt>' instruction.</li>
6461 <li>All '<tt>landingpad</tt>' instructions in a function must have the same
6462 personality function.</li>
6463</ul>
6464
6465<h5>Example:</h5>
6466<pre>
6467 ;; A landing pad which can catch an integer.
6468 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6469 catch i8** @_ZTIi
6470 ;; A landing pad that is a cleanup.
6471 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
Bill Wendlingfae14752011-08-12 20:24:12 +0000[diff] [blame]6472 cleanup
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6473 ;; A landing pad which can catch an integer and can only throw a double.
6474 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6475 catch i8** @_ZTIi
Bill Wendlingfae14752011-08-12 20:24:12 +0000[diff] [blame]6476 filter [1 x i8**] [@_ZTId]
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6477</pre>
6478
6479</div>
6480
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6481</div>
6482
6483</div>
6484
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6485<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6486<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]6487<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6488
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6489<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6490
6491<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6492 well known names and semantics and are required to follow certain
6493 restrictions. Overall, these intrinsics represent an extension mechanism for
6494 the LLVM language that does not require changing all of the transformations
6495 in LLVM when adding to the language (or the bitcode reader/writer, the
6496 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6497
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]6498<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6499 prefix is reserved in LLVM for intrinsic names; thus, function names may not
6500 begin with this prefix. Intrinsic functions must always be external
6501 functions: you cannot define the body of intrinsic functions. Intrinsic
6502 functions may only be used in call or invoke instructions: it is illegal to
6503 take the address of an intrinsic function. Additionally, because intrinsic
6504 functions are part of the LLVM language, it is required if any are added that
6505 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6506
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6507<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
6508 family of functions that perform the same operation but on different data
6509 types. Because LLVM can represent over 8 million different integer types,
6510 overloading is used commonly to allow an intrinsic function to operate on any
6511 integer type. One or more of the argument types or the result type can be
6512 overloaded to accept any integer type. Argument types may also be defined as
6513 exactly matching a previous argument's type or the result type. This allows
6514 an intrinsic function which accepts multiple arguments, but needs all of them
6515 to be of the same type, to only be overloaded with respect to a single
6516 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6517
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6518<p>Overloaded intrinsics will have the names of its overloaded argument types
6519 encoded into its function name, each preceded by a period. Only those types
6520 which are overloaded result in a name suffix. Arguments whose type is matched
6521 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6522 can take an integer of any width and returns an integer of exactly the same
6523 integer width. This leads to a family of functions such as
6524 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6525 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6526 suffix is required. Because the argument's type is matched against the return
6527 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6528
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6529<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6530 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6531
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6532<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6533<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6534 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6535</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6536
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6537<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6538
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6539<p>Variable argument support is defined in LLVM with
6540 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6541 intrinsic functions. These functions are related to the similarly named
6542 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6543
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6544<p>All of these functions operate on arguments that use a target-specific value
6545 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6546 not define what this type is, so all transformations should be prepared to
6547 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6548
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]6549<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6550 instruction and the variable argument handling intrinsic functions are
6551 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6552
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]6553<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6554define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6555 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6556 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6557 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6558 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6559
6560 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6561 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6562
6563 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6564 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6565 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6566 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6567 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6568
6569 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6570 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]6571 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6572}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6573
6574declare void @llvm.va_start(i8*)
6575declare void @llvm.va_copy(i8*, i8*)
6576declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6577</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6578
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6579<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6580<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6581 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6582</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6583
6584
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6585<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6586
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6587<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6588<pre>
6589 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6590</pre>
6591
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6592<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6593<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6594 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6595
6596<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6597<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6598
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6599<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6600<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6601 macro available in C. In a target-dependent way, it initializes
6602 the <tt>va_list</tt> element to which the argument points, so that the next
6603 call to <tt>va_arg</tt> will produce the first variable argument passed to
6604 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6605 need to know the last argument of the function as the compiler can figure
6606 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6607
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6608</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6609
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6610<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6611<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6612 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6613</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6614
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6615<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6616
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6617<h5>Syntax:</h5>
6618<pre>
6619 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6620</pre>
6621
6622<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6623<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6624 which has been initialized previously
6625 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6626 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6627
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6628<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6629<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6630
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6631<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6632<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6633 macro available in C. In a target-dependent way, it destroys
6634 the <tt>va_list</tt> element to which the argument points. Calls
6635 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6636 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6637 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6638
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6639</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6640
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6641<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6642<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6643 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6644</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6645
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6646<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6647
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6648<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6649<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6650 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6651</pre>
6652
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6653<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6654<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6655 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6656
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6657<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6658<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6659 The second argument is a pointer to a <tt>va_list</tt> element to copy
6660 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6661
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6662<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6663<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6664 macro available in C. In a target-dependent way, it copies the
6665 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6666 element. This intrinsic is necessary because
6667 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6668 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6669
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6670</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6671
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6672</div>
6673
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6674<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6675<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6676 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6677</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6678
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6679<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6680
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6681<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]6682Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6683intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6684roots on the stack</a>, as well as garbage collector implementations that
6685require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6686barriers. Front-ends for type-safe garbage collected languages should generate
6687these intrinsics to make use of the LLVM garbage collectors. For more details,
6688see <a href="GarbageCollection.html">Accurate Garbage Collection with
6689LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6690
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6691<p>The garbage collection intrinsics only operate on objects in the generic
6692 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6693
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6694<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6695<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6696 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6697</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6698
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6699<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6700
6701<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6702<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6703 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6704</pre>
6705
6706<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]6707<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6708 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6709
6710<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6711<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6712 root pointer. The second pointer (which must be either a constant or a
6713 global value address) contains the meta-data to be associated with the
6714 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6715
6716<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]6717<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6718 location. At compile-time, the code generator generates information to allow
6719 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6720 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6721 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6722
6723</div>
6724
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6725<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6726<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6727 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6728</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6729
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6730<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6731
6732<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6733<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6734 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6735</pre>
6736
6737<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6738<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6739 locations, allowing garbage collector implementations that require read
6740 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6741
6742<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6743<p>The second argument is the address to read from, which should be an address
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6744 allocated from the garbage collector. The first object is a pointer to the
6745 start of the referenced object, if needed by the language runtime (otherwise
6746 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6747
6748<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6749<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6750 instruction, but may be replaced with substantially more complex code by the
6751 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6752 may only be used in a function which <a href="#gc">specifies a GC
6753 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6754
6755</div>
6756
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6757<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6758<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6759 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6760</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6761
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6762<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6763
6764<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6765<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6766 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6767</pre>
6768
6769<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6770<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6771 locations, allowing garbage collector implementations that require write
6772 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6773
6774<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6775<p>The first argument is the reference to store, the second is the start of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776 object to store it to, and the third is the address of the field of Obj to
6777 store to. If the runtime does not require a pointer to the object, Obj may
6778 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6779
6780<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6781<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6782 instruction, but may be replaced with substantially more complex code by the
6783 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6784 may only be used in a function which <a href="#gc">specifies a GC
6785 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6786
6787</div>
6788
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6789</div>
6790
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6791<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6792<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6793 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6794</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6795
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6796<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6797
6798<p>These intrinsics are provided by LLVM to expose special features that may
6799 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6800
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6801<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6802<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6803 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6804</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6805
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6806<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6807
6808<h5>Syntax:</h5>
6809<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6810 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6811</pre>
6812
6813<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6814<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6815 target-specific value indicating the return address of the current function
6816 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6817
6818<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6819<p>The argument to this intrinsic indicates which function to return the address
6820 for. Zero indicates the calling function, one indicates its caller, etc.
6821 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6822
6823<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6824<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6825 indicating the return address of the specified call frame, or zero if it
6826 cannot be identified. The value returned by this intrinsic is likely to be
6827 incorrect or 0 for arguments other than zero, so it should only be used for
6828 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6829
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6830<p>Note that calling this intrinsic does not prevent function inlining or other
6831 aggressive transformations, so the value returned may not be that of the
6832 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6833
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6834</div>
6835
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6836<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6837<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6838 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6839</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6840
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6841<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6842
6843<h5>Syntax:</h5>
6844<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6845 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6846</pre>
6847
6848<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6849<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6850 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6851
6852<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6853<p>The argument to this intrinsic indicates which function to return the frame
6854 pointer for. Zero indicates the calling function, one indicates its caller,
6855 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6856
6857<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6858<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6859 indicating the frame address of the specified call frame, or zero if it
6860 cannot be identified. The value returned by this intrinsic is likely to be
6861 incorrect or 0 for arguments other than zero, so it should only be used for
6862 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6863
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6864<p>Note that calling this intrinsic does not prevent function inlining or other
6865 aggressive transformations, so the value returned may not be that of the
6866 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6867
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6868</div>
6869
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6870<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6871<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6872 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6873</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6874
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6875<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6876
6877<h5>Syntax:</h5>
6878<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6879 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6880</pre>
6881
6882<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6883<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6884 of the function stack, for use
6885 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6886 useful for implementing language features like scoped automatic variable
6887 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6888
6889<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6890<p>This intrinsic returns a opaque pointer value that can be passed
6891 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6892 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6893 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6894 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6895 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6896 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6897
6898</div>
6899
6900<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6901<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6902 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6903</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6904
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6905<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6906
6907<h5>Syntax:</h5>
6908<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6909 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6910</pre>
6911
6912<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6913<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6914 the function stack to the state it was in when the
6915 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6916 executed. This is useful for implementing language features like scoped
6917 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6918
6919<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6920<p>See the description
6921 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6922
6923</div>
6924
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6925<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6926<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6927 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6928</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6929
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6930<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6931
6932<h5>Syntax:</h5>
6933<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6934 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;, i32 &lt;cache type&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6935</pre>
6936
6937<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6938<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6939 insert a prefetch instruction if supported; otherwise, it is a noop.
6940 Prefetches have no effect on the behavior of the program but can change its
6941 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6942
6943<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6944<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6945 specifier determining if the fetch should be for a read (0) or write (1),
6946 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6947 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6948 specifies whether the prefetch is performed on the data (1) or instruction (0)
6949 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6950 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6951
6952<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6953<p>This intrinsic does not modify the behavior of the program. In particular,
6954 prefetches cannot trap and do not produce a value. On targets that support
6955 this intrinsic, the prefetch can provide hints to the processor cache for
6956 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6957
6958</div>
6959
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6960<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6961<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6962 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6963</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6964
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6965<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6966
6967<h5>Syntax:</h5>
6968<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6969 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6970</pre>
6971
6972<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6973<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6974 Counter (PC) in a region of code to simulators and other tools. The method
6975 is target specific, but it is expected that the marker will use exported
6976 symbols to transmit the PC of the marker. The marker makes no guarantees
6977 that it will remain with any specific instruction after optimizations. It is
6978 possible that the presence of a marker will inhibit optimizations. The
6979 intended use is to be inserted after optimizations to allow correlations of
6980 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6981
6982<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6983<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6984
6985<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6986<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6987 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6988
6989</div>
6990
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6991<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6992<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6993 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6994</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6995
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6996<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6997
6998<h5>Syntax:</h5>
6999<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7000 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]7001</pre>
7002
7003<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7004<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
7005 counter register (or similar low latency, high accuracy clocks) on those
7006 targets that support it. On X86, it should map to RDTSC. On Alpha, it
7007 should map to RPCC. As the backing counters overflow quickly (on the order
7008 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]7009
7010<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7011<p>When directly supported, reading the cycle counter should not modify any
7012 memory. Implementations are allowed to either return a application specific
7013 value or a system wide value. On backends without support, this is lowered
7014 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]7015
7016</div>
7017
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7018</div>
7019
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7020<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7021<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7022 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7023</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7024
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7025<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7026
7027<p>LLVM provides intrinsics for a few important standard C library functions.
7028 These intrinsics allow source-language front-ends to pass information about
7029 the alignment of the pointer arguments to the code generator, providing
7030 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7031
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7032<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7033<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]7034 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7035</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7036
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7037<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7038
7039<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7040<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
Mon P Wang508127b2010-04-07 06:35:53 +0000[diff] [blame]7041 integer bit width and for different address spaces. Not all targets support
7042 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7043
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7044<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]7045 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7046 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]7047 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7048 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7049</pre>
7050
7051<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7052<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
7053 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7054
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7055<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7056 intrinsics do not return a value, takes extra alignment/isvolatile arguments
7057 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7058
7059<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7060
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7061<p>The first argument is a pointer to the destination, the second is a pointer
7062 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7063 number of bytes to copy, the fourth argument is the alignment of the
7064 source and destination locations, and the fifth is a boolean indicating a
7065 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7066
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7067<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7068 then the caller guarantees that both the source and destination pointers are
7069 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]7070
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]7071<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
7072 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
7073 The detailed access behavior is not very cleanly specified and it is unwise
7074 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7075
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7076<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7077
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7078<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
7079 source location to the destination location, which are not allowed to
7080 overlap. It copies "len" bytes of memory over. If the argument is known to
7081 be aligned to some boundary, this can be specified as the fourth argument,
7082 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7083
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]7084</div>
7085
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7086<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7087<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]7088 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7089</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7090
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7091<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7092
7093<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]7094<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Mon P Wang508127b2010-04-07 06:35:53 +0000[diff] [blame]7095 width and for different address space. Not all targets support all bit
7096 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7097
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7098<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]7099 declare void @llvm.memmove.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7100 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]7101 declare void @llvm.memmove.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7102 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7103</pre>
7104
7105<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7106<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
7107 source location to the destination location. It is similar to the
7108 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
7109 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7110
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7111<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7112 intrinsics do not return a value, takes extra alignment/isvolatile arguments
7113 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7114
7115<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7116
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7117<p>The first argument is a pointer to the destination, the second is a pointer
7118 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7119 number of bytes to copy, the fourth argument is the alignment of the
7120 source and destination locations, and the fifth is a boolean indicating a
7121 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7122
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7123<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7124 then the caller guarantees that the source and destination pointers are
7125 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]7126
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]7127<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
7128 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
7129 The detailed access behavior is not very cleanly specified and it is unwise
7130 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7131
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7132<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7133
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7134<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
7135 source location to the destination location, which may overlap. It copies
7136 "len" bytes of memory over. If the argument is known to be aligned to some
7137 boundary, this can be specified as the fourth argument, otherwise it should
7138 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7139
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]7140</div>
7141
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7142<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7143<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]7144 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7145</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7146
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7147<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7148
7149<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]7150<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]7151 width and for different address spaces. However, not all targets support all
7152 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7153
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7154<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]7155 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]7156 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]7157 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]7158 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7159</pre>
7160
7161<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7162<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
7163 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7164
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7165<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]7166 intrinsic does not return a value and takes extra alignment/volatile
7167 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7168
7169<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7170<p>The first argument is a pointer to the destination to fill, the second is the
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]7171 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7172 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]7173 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7174
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7175<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7176 then the caller guarantees that the destination pointer is aligned to that
7177 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7178
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]7179<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
7180 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
7181 The detailed access behavior is not very cleanly specified and it is unwise
7182 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]7183
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7184<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7185<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
7186 at the destination location. If the argument is known to be aligned to some
7187 boundary, this can be specified as the fourth argument, otherwise it should
7188 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7189
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]7190</div>
7191
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]7192<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7193<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]7194 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7195</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]7196
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7197<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]7198
7199<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7200<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
7201 floating point or vector of floating point type. Not all targets support all
7202 types however.</p>
7203
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]7204<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]7205 declare float @llvm.sqrt.f32(float %Val)
7206 declare double @llvm.sqrt.f64(double %Val)
7207 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
7208 declare fp128 @llvm.sqrt.f128(fp128 %Val)
7209 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]7210</pre>
7211
7212<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7213<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
7214 returning the same value as the libm '<tt>sqrt</tt>' functions would.
7215 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
7216 behavior for negative numbers other than -0.0 (which allows for better
7217 optimization, because there is no need to worry about errno being
7218 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]7219
7220<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7221<p>The argument and return value are floating point numbers of the same
7222 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]7223
7224<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7225<p>This function returns the sqrt of the specified operand if it is a
7226 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]7227
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]7228</div>
7229
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7230<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7231<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]7232 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7233</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7234
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7235<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7236
7237<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7238<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
7239 floating point or vector of floating point type. Not all targets support all
7240 types however.</p>
7241
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7242<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]7243 declare float @llvm.powi.f32(float %Val, i32 %power)
7244 declare double @llvm.powi.f64(double %Val, i32 %power)
7245 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
7246 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
7247 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7248</pre>
7249
7250<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7251<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
7252 specified (positive or negative) power. The order of evaluation of
7253 multiplications is not defined. When a vector of floating point type is
7254 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7255
7256<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7257<p>The second argument is an integer power, and the first is a value to raise to
7258 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7259
7260<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7261<p>This function returns the first value raised to the second power with an
7262 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7263
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]7264</div>
7265
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7266<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7267<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7268 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7269</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7271<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7272
7273<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7274<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
7275 floating point or vector of floating point type. Not all targets support all
7276 types however.</p>
7277
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7278<pre>
7279 declare float @llvm.sin.f32(float %Val)
7280 declare double @llvm.sin.f64(double %Val)
7281 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
7282 declare fp128 @llvm.sin.f128(fp128 %Val)
7283 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
7284</pre>
7285
7286<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7287<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7288
7289<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7290<p>The argument and return value are floating point numbers of the same
7291 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7292
7293<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7294<p>This function returns the sine of the specified operand, returning the same
7295 values as the libm <tt>sin</tt> functions would, and handles error conditions
7296 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7297
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7298</div>
7299
7300<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7301<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7302 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7303</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7304
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7305<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7306
7307<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7308<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
7309 floating point or vector of floating point type. Not all targets support all
7310 types however.</p>
7311
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7312<pre>
7313 declare float @llvm.cos.f32(float %Val)
7314 declare double @llvm.cos.f64(double %Val)
7315 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
7316 declare fp128 @llvm.cos.f128(fp128 %Val)
7317 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
7318</pre>
7319
7320<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7321<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7322
7323<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7324<p>The argument and return value are floating point numbers of the same
7325 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7326
7327<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7328<p>This function returns the cosine of the specified operand, returning the same
7329 values as the libm <tt>cos</tt> functions would, and handles error conditions
7330 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7331
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7332</div>
7333
7334<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7335<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7336 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7337</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7338
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7339<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7340
7341<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7342<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
7343 floating point or vector of floating point type. Not all targets support all
7344 types however.</p>
7345
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7346<pre>
7347 declare float @llvm.pow.f32(float %Val, float %Power)
7348 declare double @llvm.pow.f64(double %Val, double %Power)
7349 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
7350 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
7351 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
7352</pre>
7353
7354<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7355<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
7356 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7357
7358<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7359<p>The second argument is a floating point power, and the first is a value to
7360 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7361
7362<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7363<p>This function returns the first value raised to the second power, returning
7364 the same values as the libm <tt>pow</tt> functions would, and handles error
7365 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7366
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]7367</div>
7368
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]7369<!-- _______________________________________________________________________ -->
7370<h4>
7371 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
7372</h4>
7373
7374<div>
7375
7376<h5>Syntax:</h5>
7377<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
7378 floating point or vector of floating point type. Not all targets support all
7379 types however.</p>
7380
7381<pre>
7382 declare float @llvm.exp.f32(float %Val)
7383 declare double @llvm.exp.f64(double %Val)
7384 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
7385 declare fp128 @llvm.exp.f128(fp128 %Val)
7386 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
7387</pre>
7388
7389<h5>Overview:</h5>
7390<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
7391
7392<h5>Arguments:</h5>
7393<p>The argument and return value are floating point numbers of the same
7394 type.</p>
7395
7396<h5>Semantics:</h5>
7397<p>This function returns the same values as the libm <tt>exp</tt> functions
7398 would, and handles error conditions in the same way.</p>
7399
7400</div>
7401
7402<!-- _______________________________________________________________________ -->
7403<h4>
7404 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
7405</h4>
7406
7407<div>
7408
7409<h5>Syntax:</h5>
7410<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
7411 floating point or vector of floating point type. Not all targets support all
7412 types however.</p>
7413
7414<pre>
7415 declare float @llvm.log.f32(float %Val)
7416 declare double @llvm.log.f64(double %Val)
7417 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
7418 declare fp128 @llvm.log.f128(fp128 %Val)
7419 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
7420</pre>
7421
7422<h5>Overview:</h5>
7423<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
7424
7425<h5>Arguments:</h5>
7426<p>The argument and return value are floating point numbers of the same
7427 type.</p>
7428
7429<h5>Semantics:</h5>
7430<p>This function returns the same values as the libm <tt>log</tt> functions
7431 would, and handles error conditions in the same way.</p>
7432
Nick Lewyckycd196f62011-10-31 01:32:21 +0000[diff] [blame]7433</div>
7434
7435<!-- _______________________________________________________________________ -->
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]7436<h4>
7437 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
7438</h4>
7439
7440<div>
7441
7442<h5>Syntax:</h5>
7443<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
7444 floating point or vector of floating point type. Not all targets support all
7445 types however.</p>
7446
7447<pre>
7448 declare float @llvm.fma.f32(float %a, float %b, float %c)
7449 declare double @llvm.fma.f64(double %a, double %b, double %c)
7450 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
7451 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
7452 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
7453</pre>
7454
7455<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]7456<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]7457 operation.</p>
7458
7459<h5>Arguments:</h5>
7460<p>The argument and return value are floating point numbers of the same
7461 type.</p>
7462
7463<h5>Semantics:</h5>
7464<p>This function returns the same values as the libm <tt>fma</tt> functions
7465 would.</p>
7466
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]7467</div>
7468
NAKAMURA Takumia35cdd62011-10-31 13:04:26 +0000[diff] [blame]7469</div>
7470
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7471<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7472<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7473 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7474</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7475
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7476<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7477
7478<p>LLVM provides intrinsics for a few important bit manipulation operations.
7479 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7480
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7481<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7482<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]7483 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7484</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7485
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7486<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7487
7488<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]7489<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7490 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
7491
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7492<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7493 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
7494 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
7495 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7496</pre>
7497
7498<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7499<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
7500 values with an even number of bytes (positive multiple of 16 bits). These
7501 are useful for performing operations on data that is not in the target's
7502 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7503
7504<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7505<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
7506 and low byte of the input i16 swapped. Similarly,
7507 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
7508 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
7509 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
7510 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
7511 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
7512 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7513
7514</div>
7515
7516<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7517<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]7518 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7519</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7520
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7521<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7522
7523<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]7524<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7525 width, or on any vector with integer elements. Not all targets support all
7526 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7527
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7528<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7529 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7530 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7531 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7532 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7533 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7534 declare &lt;2 x i32&gt; @llvm.ctpop.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7535</pre>
7536
7537<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7538<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7539 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7540
7541<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7542<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7543 integer type, or a vector with integer elements.
7544 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7545
7546<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7547<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7548 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7549
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7550</div>
7551
7552<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7553<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7554 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7555</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7556
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7557<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7558
7559<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7560<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7561 integer bit width, or any vector whose elements are integers. Not all
7562 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7563
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7564<pre>
Chandler Carruthf6bb2782011-12-12 04:36:04 +0000[diff] [blame]7565 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7566 declare i16 @llvm.ctlz.i16 (i16 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7567 declare i32 @llvm.ctlz.i32 (i32 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7568 declare i64 @llvm.ctlz.i64 (i64 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7569 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7570 declase &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7571</pre>
7572
7573<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7574<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7575 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7576
7577<h5>Arguments:</h5>
Chandler Carruthf6bb2782011-12-12 04:36:04 +0000[diff] [blame]7578<p>The first argument is the value to be counted. This argument may be of any
7579 integer type, or a vectory with integer element type. The return type
7580 must match the first argument type.</p>
7581
7582<p>The second argument must be a constant and is a flag to indicate whether the
7583 intrinsic should ensure that a zero as the first argument produces a defined
7584 result. Historically some architectures did not provide a defined result for
7585 zero values as efficiently, and many algorithms are now predicated on
7586 avoiding zero-value inputs.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7587
7588<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7589<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Chandler Carruthf6bb2782011-12-12 04:36:04 +0000[diff] [blame]7590 zeros in a variable, or within each element of the vector.
7591 If <tt>src == 0</tt> then the result is the size in bits of the type of
7592 <tt>src</tt> if <tt>is_zero_undef == 0</tt> and <tt>undef</tt> otherwise.
7593 For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7594
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7595</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]7596
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7597<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7598<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7599 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7600</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7601
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7602<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7603
7604<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7605<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7606 integer bit width, or any vector of integer elements. Not all targets
7607 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7608
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7609<pre>
Chandler Carruthf6bb2782011-12-12 04:36:04 +0000[diff] [blame]7610 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7611 declare i16 @llvm.cttz.i16 (i16 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7612 declare i32 @llvm.cttz.i32 (i32 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7613 declare i64 @llvm.cttz.i64 (i64 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7614 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
7615 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;, i1 &lt;is_zero_undef&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7616</pre>
7617
7618<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7619<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7620 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7621
7622<h5>Arguments:</h5>
Chandler Carruthf6bb2782011-12-12 04:36:04 +0000[diff] [blame]7623<p>The first argument is the value to be counted. This argument may be of any
7624 integer type, or a vectory with integer element type. The return type
7625 must match the first argument type.</p>
7626
7627<p>The second argument must be a constant and is a flag to indicate whether the
7628 intrinsic should ensure that a zero as the first argument produces a defined
7629 result. Historically some architectures did not provide a defined result for
7630 zero values as efficiently, and many algorithms are now predicated on
7631 avoiding zero-value inputs.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7632
7633<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7634<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7635 zeros in a variable, or within each element of a vector.
Chandler Carruthf6bb2782011-12-12 04:36:04 +0000[diff] [blame]7636 If <tt>src == 0</tt> then the result is the size in bits of the type of
7637 <tt>src</tt> if <tt>is_zero_undef == 0</tt> and <tt>undef</tt> otherwise.
7638 For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7639
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7640</div>
7641
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7642</div>
7643
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7644<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7645<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7646 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7647</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7648
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7649<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7650
7651<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7652
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7653<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7654<h4>
7655 <a name="int_sadd_overflow">
7656 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7657 </a>
7658</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7659
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7660<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7661
7662<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7663<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7664 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7665
7666<pre>
7667 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7668 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7669 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7670</pre>
7671
7672<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7673<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7674 a signed addition of the two arguments, and indicate whether an overflow
7675 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7676
7677<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7678<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7679 be of integer types of any bit width, but they must have the same bit
7680 width. The second element of the result structure must be of
7681 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7682 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7683
7684<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7685<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7686 a signed addition of the two variables. They return a structure &mdash; the
7687 first element of which is the signed summation, and the second element of
7688 which is a bit specifying if the signed summation resulted in an
7689 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7690
7691<h5>Examples:</h5>
7692<pre>
7693 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7694 %sum = extractvalue {i32, i1} %res, 0
7695 %obit = extractvalue {i32, i1} %res, 1
7696 br i1 %obit, label %overflow, label %normal
7697</pre>
7698
7699</div>
7700
7701<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7702<h4>
7703 <a name="int_uadd_overflow">
7704 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7705 </a>
7706</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7707
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7708<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7709
7710<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7711<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7712 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7713
7714<pre>
7715 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7716 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7717 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7718</pre>
7719
7720<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7721<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7722 an unsigned addition of the two arguments, and indicate whether a carry
7723 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7724
7725<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7726<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7727 be of integer types of any bit width, but they must have the same bit
7728 width. The second element of the result structure must be of
7729 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7730 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7731
7732<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7733<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7734 an unsigned addition of the two arguments. They return a structure &mdash;
7735 the first element of which is the sum, and the second element of which is a
7736 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7737
7738<h5>Examples:</h5>
7739<pre>
7740 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7741 %sum = extractvalue {i32, i1} %res, 0
7742 %obit = extractvalue {i32, i1} %res, 1
7743 br i1 %obit, label %carry, label %normal
7744</pre>
7745
7746</div>
7747
7748<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7749<h4>
7750 <a name="int_ssub_overflow">
7751 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7752 </a>
7753</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7754
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7755<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7756
7757<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7758<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7759 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7760
7761<pre>
7762 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7763 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7764 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7765</pre>
7766
7767<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7768<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7769 a signed subtraction of the two arguments, and indicate whether an overflow
7770 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7771
7772<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7773<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7774 be of integer types of any bit width, but they must have the same bit
7775 width. The second element of the result structure must be of
7776 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7777 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7778
7779<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7780<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7781 a signed subtraction of the two arguments. They return a structure &mdash;
7782 the first element of which is the subtraction, and the second element of
7783 which is a bit specifying if the signed subtraction resulted in an
7784 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7785
7786<h5>Examples:</h5>
7787<pre>
7788 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7789 %sum = extractvalue {i32, i1} %res, 0
7790 %obit = extractvalue {i32, i1} %res, 1
7791 br i1 %obit, label %overflow, label %normal
7792</pre>
7793
7794</div>
7795
7796<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7797<h4>
7798 <a name="int_usub_overflow">
7799 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7800 </a>
7801</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7802
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7803<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7804
7805<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7806<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7807 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7808
7809<pre>
7810 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7811 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7812 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7813</pre>
7814
7815<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7816<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7817 an unsigned subtraction of the two arguments, and indicate whether an
7818 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7819
7820<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7821<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7822 be of integer types of any bit width, but they must have the same bit
7823 width. The second element of the result structure must be of
7824 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7825 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7826
7827<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7828<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7829 an unsigned subtraction of the two arguments. They return a structure &mdash;
7830 the first element of which is the subtraction, and the second element of
7831 which is a bit specifying if the unsigned subtraction resulted in an
7832 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7833
7834<h5>Examples:</h5>
7835<pre>
7836 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7837 %sum = extractvalue {i32, i1} %res, 0
7838 %obit = extractvalue {i32, i1} %res, 1
7839 br i1 %obit, label %overflow, label %normal
7840</pre>
7841
7842</div>
7843
7844<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7845<h4>
7846 <a name="int_smul_overflow">
7847 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7848 </a>
7849</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7850
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7851<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7852
7853<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7854<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7855 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7856
7857<pre>
7858 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7859 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7860 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7861</pre>
7862
7863<h5>Overview:</h5>
7864
7865<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7866 a signed multiplication of the two arguments, and indicate whether an
7867 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7868
7869<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7870<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7871 be of integer types of any bit width, but they must have the same bit
7872 width. The second element of the result structure must be of
7873 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7874 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7875
7876<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7877<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7878 a signed multiplication of the two arguments. They return a structure &mdash;
7879 the first element of which is the multiplication, and the second element of
7880 which is a bit specifying if the signed multiplication resulted in an
7881 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7882
7883<h5>Examples:</h5>
7884<pre>
7885 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7886 %sum = extractvalue {i32, i1} %res, 0
7887 %obit = extractvalue {i32, i1} %res, 1
7888 br i1 %obit, label %overflow, label %normal
7889</pre>
7890
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7891</div>
7892
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7893<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7894<h4>
7895 <a name="int_umul_overflow">
7896 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7897 </a>
7898</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7899
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7900<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7901
7902<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7903<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7904 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7905
7906<pre>
7907 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7908 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7909 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7910</pre>
7911
7912<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7913<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7914 a unsigned multiplication of the two arguments, and indicate whether an
7915 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7916
7917<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7918<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7919 be of integer types of any bit width, but they must have the same bit
7920 width. The second element of the result structure must be of
7921 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7922 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7923
7924<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7925<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7926 an unsigned multiplication of the two arguments. They return a structure
7927 &mdash; the first element of which is the multiplication, and the second
7928 element of which is a bit specifying if the unsigned multiplication resulted
7929 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7930
7931<h5>Examples:</h5>
7932<pre>
7933 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7934 %sum = extractvalue {i32, i1} %res, 0
7935 %obit = extractvalue {i32, i1} %res, 1
7936 br i1 %obit, label %overflow, label %normal
7937</pre>
7938
7939</div>
7940
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7941</div>
7942
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7943<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7944<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7945 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7946</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7947
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7948<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7949
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7950<p>Half precision floating point is a storage-only format. This means that it is
7951 a dense encoding (in memory) but does not support computation in the
7952 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7953
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7954<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7955 value as an i16, then convert it to float with <a
7956 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7957 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7958 double etc). To store the value back to memory, it is first converted to
7959 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7960 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7961 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7962
7963<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7964<h4>
7965 <a name="int_convert_to_fp16">
7966 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7967 </a>
7968</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7969
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7970<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7971
7972<h5>Syntax:</h5>
7973<pre>
7974 declare i16 @llvm.convert.to.fp16(f32 %a)
7975</pre>
7976
7977<h5>Overview:</h5>
7978<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7979 a conversion from single precision floating point format to half precision
7980 floating point format.</p>
7981
7982<h5>Arguments:</h5>
7983<p>The intrinsic function contains single argument - the value to be
7984 converted.</p>
7985
7986<h5>Semantics:</h5>
7987<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7988 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7989 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7990 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7991
7992<h5>Examples:</h5>
7993<pre>
7994 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7995 store i16 %res, i16* @x, align 2
7996</pre>
7997
7998</div>
7999
8000<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8001<h4>
8002 <a name="int_convert_from_fp16">
8003 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
8004 </a>
8005</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]8006
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8007<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]8008
8009<h5>Syntax:</h5>
8010<pre>
8011 declare f32 @llvm.convert.from.fp16(i16 %a)
8012</pre>
8013
8014<h5>Overview:</h5>
8015<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
8016 a conversion from half precision floating point format to single precision
8017 floating point format.</p>
8018
8019<h5>Arguments:</h5>
8020<p>The intrinsic function contains single argument - the value to be
8021 converted.</p>
8022
8023<h5>Semantics:</h5>
8024<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]8025 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]8026 precision floating point format. The input half-float value is represented by
8027 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]8028
8029<h5>Examples:</h5>
8030<pre>
8031 %a = load i16* @x, align 2
8032 %res = call f32 @llvm.convert.from.fp16(i16 %a)
8033</pre>
8034
8035</div>
8036
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8037</div>
8038
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]8039<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8040<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]8041 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8042</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]8043
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8044<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]8045
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8046<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
8047 prefix), are described in
8048 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
8049 Level Debugging</a> document.</p>
8050
8051</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]8052
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8053<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8054<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8055 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8056</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8057
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8058<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8059
8060<p>The LLVM exception handling intrinsics (which all start with
8061 <tt>llvm.eh.</tt> prefix), are described in
8062 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
8063 Handling</a> document.</p>
8064
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8065</div>
8066
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8067<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8068<h3>
Duncan Sandsa0984362011-09-06 13:37:06 +0000[diff] [blame]8069 <a name="int_trampoline">Trampoline Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8070</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8071
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8072<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8073
Duncan Sandsa0984362011-09-06 13:37:06 +0000[diff] [blame]8074<p>These intrinsics make it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]8075 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
8076 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8077 function pointer lacking the nest parameter - the caller does not need to
8078 provide a value for it. Instead, the value to use is stored in advance in a
8079 "trampoline", a block of memory usually allocated on the stack, which also
8080 contains code to splice the nest value into the argument list. This is used
8081 to implement the GCC nested function address extension.</p>
8082
8083<p>For example, if the function is
8084 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
8085 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
8086 follows:</p>
8087
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]8088<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]8089 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
8090 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Duncan Sandsa0984362011-09-06 13:37:06 +0000[diff] [blame]8091 call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8*, i32, i32)* @f to i8*), i8* %nval)
8092 %p = call i8* @llvm.adjust.trampoline(i8* %tramp1)
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]8093 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8094</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8095
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8096<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
8097 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8098
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8099<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8100<h4>
8101 <a name="int_it">
8102 '<tt>llvm.init.trampoline</tt>' Intrinsic
8103 </a>
8104</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8105
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8106<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8107
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8108<h5>Syntax:</h5>
8109<pre>
Duncan Sandsa0984362011-09-06 13:37:06 +0000[diff] [blame]8110 declare void @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8111</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8112
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8113<h5>Overview:</h5>
Duncan Sandsa0984362011-09-06 13:37:06 +0000[diff] [blame]8114<p>This fills the memory pointed to by <tt>tramp</tt> with executable code,
8115 turning it into a trampoline.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8116
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8117<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8118<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
8119 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
8120 sufficiently aligned block of memory; this memory is written to by the
8121 intrinsic. Note that the size and the alignment are target-specific - LLVM
8122 currently provides no portable way of determining them, so a front-end that
8123 generates this intrinsic needs to have some target-specific knowledge.
8124 The <tt>func</tt> argument must hold a function bitcast to
8125 an <tt>i8*</tt>.</p>
8126
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8127<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8128<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsa0984362011-09-06 13:37:06 +0000[diff] [blame]8129 dependent code, turning it into a function. Then <tt>tramp</tt> needs to be
8130 passed to <a href="#int_at">llvm.adjust.trampoline</a> to get a pointer
8131 which can be <a href="#int_trampoline">bitcast (to a new function) and
8132 called</a>. The new function's signature is the same as that of
8133 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
8134 removed. At most one such <tt>nest</tt> argument is allowed, and it must be of
8135 pointer type. Calling the new function is equivalent to calling <tt>func</tt>
8136 with the same argument list, but with <tt>nval</tt> used for the missing
8137 <tt>nest</tt> argument. If, after calling <tt>llvm.init.trampoline</tt>, the
8138 memory pointed to by <tt>tramp</tt> is modified, then the effect of any later call
8139 to the returned function pointer is undefined.</p>
8140</div>
8141
8142<!-- _______________________________________________________________________ -->
8143<h4>
8144 <a name="int_at">
8145 '<tt>llvm.adjust.trampoline</tt>' Intrinsic
8146 </a>
8147</h4>
8148
8149<div>
8150
8151<h5>Syntax:</h5>
8152<pre>
8153 declare i8* @llvm.adjust.trampoline(i8* &lt;tramp&gt;)
8154</pre>
8155
8156<h5>Overview:</h5>
8157<p>This performs any required machine-specific adjustment to the address of a
8158 trampoline (passed as <tt>tramp</tt>).</p>
8159
8160<h5>Arguments:</h5>
8161<p><tt>tramp</tt> must point to a block of memory which already has trampoline code
8162 filled in by a previous call to <a href="#int_it"><tt>llvm.init.trampoline</tt>
8163 </a>.</p>
8164
8165<h5>Semantics:</h5>
8166<p>On some architectures the address of the code to be executed needs to be
8167 different to the address where the trampoline is actually stored. This
8168 intrinsic returns the executable address corresponding to <tt>tramp</tt>
8169 after performing the required machine specific adjustments.
8170 The pointer returned can then be <a href="#int_trampoline"> bitcast and
8171 executed</a>.
8172</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8173
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8174</div>
8175
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8176</div>
8177
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]8178<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8179<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8180 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8181</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8182
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8183<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8184
8185<p>This class of intrinsics exists to information about the lifetime of memory
8186 objects and ranges where variables are immutable.</p>
8187
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8188<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8189<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8190 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8191</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8192
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8193<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8194
8195<h5>Syntax:</h5>
8196<pre>
8197 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8198</pre>
8199
8200<h5>Overview:</h5>
8201<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8202 object's lifetime.</p>
8203
8204<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8205<p>The first argument is a constant integer representing the size of the
8206 object, or -1 if it is variable sized. The second argument is a pointer to
8207 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8208
8209<h5>Semantics:</h5>
8210<p>This intrinsic indicates that before this point in the code, the value of the
8211 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewyckyd20fd592009-10-27 16:56:58 +0000[diff] [blame]8212 never be used and has an undefined value. A load from the pointer that
8213 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8214 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8215
8216</div>
8217
8218<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8219<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8220 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8221</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8222
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8223<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8224
8225<h5>Syntax:</h5>
8226<pre>
8227 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8228</pre>
8229
8230<h5>Overview:</h5>
8231<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8232 object's lifetime.</p>
8233
8234<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8235<p>The first argument is a constant integer representing the size of the
8236 object, or -1 if it is variable sized. The second argument is a pointer to
8237 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8238
8239<h5>Semantics:</h5>
8240<p>This intrinsic indicates that after this point in the code, the value of the
8241 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8242 never be used and has an undefined value. Any stores into the memory object
8243 following this intrinsic may be removed as dead.
8244
8245</div>
8246
8247<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8248<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8249 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8250</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8251
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8252<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8253
8254<h5>Syntax:</h5>
8255<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]8256 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8257</pre>
8258
8259<h5>Overview:</h5>
8260<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8261 a memory object will not change.</p>
8262
8263<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8264<p>The first argument is a constant integer representing the size of the
8265 object, or -1 if it is variable sized. The second argument is a pointer to
8266 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8267
8268<h5>Semantics:</h5>
8269<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8270 the return value, the referenced memory location is constant and
8271 unchanging.</p>
8272
8273</div>
8274
8275<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8276<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8277 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8278</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8279
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8280<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8281
8282<h5>Syntax:</h5>
8283<pre>
8284 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8285</pre>
8286
8287<h5>Overview:</h5>
8288<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8289 a memory object are mutable.</p>
8290
8291<h5>Arguments:</h5>
8292<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8293 The second argument is a constant integer representing the size of the
8294 object, or -1 if it is variable sized and the third argument is a pointer
8295 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8296
8297<h5>Semantics:</h5>
8298<p>This intrinsic indicates that the memory is mutable again.</p>
8299
8300</div>
8301
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8302</div>
8303
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8304<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8305<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8306 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8307</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8308
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8309<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8310
8311<p>This class of intrinsics is designed to be generic and has no specific
8312 purpose.</p>
8313
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8314<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8315<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8316 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8317</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8318
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8319<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8320
8321<h5>Syntax:</h5>
8322<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8323 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8324</pre>
8325
8326<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8327<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8328
8329<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8330<p>The first argument is a pointer to a value, the second is a pointer to a
8331 global string, the third is a pointer to a global string which is the source
8332 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8333
8334<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8335<p>This intrinsic allows annotation of local variables with arbitrary strings.
8336 This can be useful for special purpose optimizations that want to look for
John Criswellf0d536a2011-08-19 16:57:55 +0000[diff] [blame]8337 these annotations. These have no other defined use; they are ignored by code
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8338 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8339
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8340</div>
8341
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8342<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8343<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]8344 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8345</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8346
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8347<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8348
8349<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8350<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8351 any integer bit width.</p>
8352
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8353<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8354 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8355 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8356 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8357 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8358 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8359</pre>
8360
8361<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8362<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8363
8364<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8365<p>The first argument is an integer value (result of some expression), the
8366 second is a pointer to a global string, the third is a pointer to a global
8367 string which is the source file name, and the last argument is the line
8368 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8369
8370<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8371<p>This intrinsic allows annotations to be put on arbitrary expressions with
8372 arbitrary strings. This can be useful for special purpose optimizations that
John Criswellf0d536a2011-08-19 16:57:55 +0000[diff] [blame]8373 want to look for these annotations. These have no other defined use; they
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8374 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8375
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8376</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8377
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8378<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8379<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8380 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8381</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8382
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8383<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8384
8385<h5>Syntax:</h5>
8386<pre>
8387 declare void @llvm.trap()
8388</pre>
8389
8390<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8391<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8392
8393<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8394<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8395
8396<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8397<p>This intrinsics is lowered to the target dependent trap instruction. If the
8398 target does not have a trap instruction, this intrinsic will be lowered to
8399 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8400
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8401</div>
8402
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8403<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8404<h4>
Dan Gohmandfab4432012-05-11 00:19:32 +0000[diff] [blame^]8405 <a name="int_debugger">'<tt>llvm.debugger</tt>' Intrinsic</a>
8406</h4>
8407
8408<div>
8409
8410<h5>Syntax:</h5>
8411<pre>
8412 declare void @llvm.debugger()
8413</pre>
8414
8415<h5>Overview:</h5>
8416<p>The '<tt>llvm.debugger</tt>' intrinsic.</p>
8417
8418<h5>Arguments:</h5>
8419<p>None.</p>
8420
8421<h5>Semantics:</h5>
8422<p>This intrinsic is lowered to code which is intended to cause an execution
8423 trap with the intention of requesting the attention of a debugger.</p>
8424
8425</div>
8426
8427<!-- _______________________________________________________________________ -->
8428<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]8429 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8430</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8431
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8432<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8433
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8434<h5>Syntax:</h5>
8435<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8436 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8437</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8438
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8439<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8440<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8441 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8442 ensure that it is placed on the stack before local variables.</p>
8443
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8444<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8445<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8446 arguments. The first argument is the value loaded from the stack
8447 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8448 that has enough space to hold the value of the guard.</p>
8449
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8450<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8451<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8452 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8453 stack. This is to ensure that if a local variable on the stack is
8454 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8455 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8456 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8457 function.</p>
8458
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8459</div>
8460
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8461<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8462<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8463 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8464</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8465
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8466<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8467
8468<h5>Syntax:</h5>
8469<pre>
Nuno Lopes01547b32012-05-09 15:52:43 +0000[diff] [blame]8470 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;min&gt;, i32 &lt;runtime&gt;)
8471 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;min&gt;, i32 &lt;runtime&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8472</pre>
8473
8474<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8475<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8476 the optimizers to determine at compile time whether a) an operation (like
8477 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8478 runtime check for overflow isn't necessary. An object in this context means
8479 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8480
8481<h5>Arguments:</h5>
Nuno Lopes01547b32012-05-09 15:52:43 +0000[diff] [blame]8482<p>The <tt>llvm.objectsize</tt> intrinsic takes three arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8483 argument is a pointer to or into the <tt>object</tt>. The second argument
Nuno Lopes01547b32012-05-09 15:52:43 +0000[diff] [blame]8484 is a boolean and determines whether <tt>llvm.objectsize</tt> returns 0 (if true)
8485 or -1 (if false) when the object size is unknown.
8486 The third argument, <tt>runtime</tt>, indicates whether the compiler is allowed
8487 to return a non-constant value. The higher the value, the higher the potential
8488 run-time performance impact.
8489 The second and third arguments only accepts constants.</p>
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8490
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8491<h5>Semantics:</h5>
Nuno Lopes01547b32012-05-09 15:52:43 +0000[diff] [blame]8492<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to a constant representing
8493 the size of the object concerned. If the size cannot be determined at compile
8494 time, <tt>llvm.objectsize</tt> either returns <tt>i32/i64 -1 or 0</tt>
8495 (depending on the <tt>min</tt> argument) if <tt>runtime</tt> is 0, or a run-time
8496 value (if <tt>runtime</tt> &gt; 0 and an expression could be generated).</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8497
8498</div>
Jakub Staszak5fef7922011-12-04 18:29:26 +0000[diff] [blame]8499<!-- _______________________________________________________________________ -->
8500<h4>
8501 <a name="int_expect">'<tt>llvm.expect</tt>' Intrinsic</a>
8502</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8503
Jakub Staszak5fef7922011-12-04 18:29:26 +0000[diff] [blame]8504<div>
8505
8506<h5>Syntax:</h5>
8507<pre>
8508 declare i32 @llvm.expect.i32(i32 &lt;val&gt;, i32 &lt;expected_val&gt;)
8509 declare i64 @llvm.expect.i64(i64 &lt;val&gt;, i64 &lt;expected_val&gt;)
8510</pre>
8511
8512<h5>Overview:</h5>
8513<p>The <tt>llvm.expect</tt> intrinsic provides information about expected (the
8514 most probable) value of <tt>val</tt>, which can be used by optimizers.</p>
8515
8516<h5>Arguments:</h5>
8517<p>The <tt>llvm.expect</tt> intrinsic takes two arguments. The first
8518 argument is a value. The second argument is an expected value, this needs to
8519 be a constant value, variables are not allowed.</p>
8520
8521<h5>Semantics:</h5>
8522<p>This intrinsic is lowered to the <tt>val</tt>.</p>
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8523</div>
8524
8525</div>
8526
Jakub Staszak5fef7922011-12-04 18:29:26 +0000[diff] [blame]8527</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8528<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8529<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8530<address>
8531 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8532 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8533 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8534 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8535
8536 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8537 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8538 Last modified: $Date$
8539</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8540
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8541</body>
8542</html>