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gerrit-public.fairphone.software / toolchain / llvm-project / c9a551ebed9fe4e5320a8c3d216d98907a8f20cc / . / 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.">
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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>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill 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 Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]95 <li><a href="#trapvalues">Trap 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>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]104 </ol>
105 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]106 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
107 <ol>
108 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]109 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
110 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]111 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
112 Global Variable</a></li>
113 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
114 Global Variable</a></li>
115 </ol>
116 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#instref">Instruction Reference</a>
118 <ol>
119 <li><a href="#terminators">Terminator Instructions</a>
120 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
122 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]124 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]125 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Bill Wendling6c923bb2011-07-27 20:18:04 +0000[diff] [blame]127 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]128 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]129 </ol>
130 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]131 <li><a href="#binaryops">Binary Operations</a>
132 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]137 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]138 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]139 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
140 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
141 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]142 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
143 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
144 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]145 </ol>
146 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]147 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
148 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]149 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
150 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
151 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]154 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]157 <li><a href="#vectorops">Vector Operations</a>
158 <ol>
159 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
160 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
161 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]162 </ol>
163 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]164 <li><a href="#aggregateops">Aggregate Operations</a>
165 <ol>
166 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
167 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
168 </ol>
169 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]170 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]171 <ol>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame^]172 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
173 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
174 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
175 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
176 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
177 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]178 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]179 </ol>
180 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]181 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]182 <ol>
183 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
184 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
186 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
187 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]188 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
189 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
190 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
191 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]192 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
193 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]194 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]195 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]196 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]197 <li><a href="#otherops">Other Operations</a>
198 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]199 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
200 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]201 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]202 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]203 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]204 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]205 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]206 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]207 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]208 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]209 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]210 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]211 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
212 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
214 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
215 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]216 </ol>
217 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]218 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
219 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]220 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
221 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
222 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]223 </ol>
224 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]225 <li><a href="#int_codegen">Code Generator Intrinsics</a>
226 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]227 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
228 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
229 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
230 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
231 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
232 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]233 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]234 </ol>
235 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]236 <li><a href="#int_libc">Standard C Library Intrinsics</a>
237 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]238 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]243 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
244 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
245 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]246 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
247 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]248 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]249 </ol>
250 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]251 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]252 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]253 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]254 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
255 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
256 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]259 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
260 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]261 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
262 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
263 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
264 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
265 <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]266 <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]267 </ol>
268 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]269 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
270 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]271 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
272 <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]273 </ol>
274 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]275 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]276 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]277 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]278 <ol>
279 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]280 </ol>
281 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]282 <li><a href="#int_atomics">Atomic intrinsics</a>
283 <ol>
284 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
285 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
286 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
287 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
288 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
289 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
290 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
291 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
292 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
293 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
294 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
295 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
296 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
297 </ol>
298 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]299 <li><a href="#int_memorymarkers">Memory Use Markers</a>
300 <ol>
301 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
302 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
303 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
304 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
305 </ol>
306 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]307 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]308 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]309 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]310 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]311 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]312 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]313 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]314 '<tt>llvm.trap</tt>' Intrinsic</a></li>
315 <li><a href="#int_stackprotector">
316 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]317 <li><a href="#int_objectsize">
318 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]319 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]320 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]321 </ol>
322 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]323</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
325<div class="doc_author">
326 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
327 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]328</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]329
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]330<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]331<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]332<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]333
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]334<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]335
336<p>This document is a reference manual for the LLVM assembly language. LLVM is
337 a Static Single Assignment (SSA) based representation that provides type
338 safety, low-level operations, flexibility, and the capability of representing
339 'all' high-level languages cleanly. It is the common code representation
340 used throughout all phases of the LLVM compilation strategy.</p>
341
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]342</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]343
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]344<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]345<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]346<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]347
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]348<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]349
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]350<p>The LLVM code representation is designed to be used in three different forms:
351 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
352 for fast loading by a Just-In-Time compiler), and as a human readable
353 assembly language representation. This allows LLVM to provide a powerful
354 intermediate representation for efficient compiler transformations and
355 analysis, while providing a natural means to debug and visualize the
356 transformations. The three different forms of LLVM are all equivalent. This
357 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]358
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]359<p>The LLVM representation aims to be light-weight and low-level while being
360 expressive, typed, and extensible at the same time. It aims to be a
361 "universal IR" of sorts, by being at a low enough level that high-level ideas
362 may be cleanly mapped to it (similar to how microprocessors are "universal
363 IR's", allowing many source languages to be mapped to them). By providing
364 type information, LLVM can be used as the target of optimizations: for
365 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]366 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]367 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]368
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]369<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]370<h4>
371 <a name="wellformed">Well-Formedness</a>
372</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]373
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]374<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]376<p>It is important to note that this document describes 'well formed' LLVM
377 assembly language. There is a difference between what the parser accepts and
378 what is considered 'well formed'. For example, the following instruction is
379 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]380
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]381<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]382%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]383</pre>
384
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]385<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
386 LLVM infrastructure provides a verification pass that may be used to verify
387 that an LLVM module is well formed. This pass is automatically run by the
388 parser after parsing input assembly and by the optimizer before it outputs
389 bitcode. The violations pointed out by the verifier pass indicate bugs in
390 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]391
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]392</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]393
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]394</div>
395
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]396<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]397
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]398<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]399<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]400<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]401
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]402<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]403
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]404<p>LLVM identifiers come in two basic types: global and local. Global
405 identifiers (functions, global variables) begin with the <tt>'@'</tt>
406 character. Local identifiers (register names, types) begin with
407 the <tt>'%'</tt> character. Additionally, there are three different formats
408 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]409
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]410<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]411 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]412 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
413 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
414 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
415 other characters in their names can be surrounded with quotes. Special
416 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
417 ASCII code for the character in hexadecimal. In this way, any character
418 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]419
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]420 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]421 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]422
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]423 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]424 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]425</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]427<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]428 don't need to worry about name clashes with reserved words, and the set of
429 reserved words may be expanded in the future without penalty. Additionally,
430 unnamed identifiers allow a compiler to quickly come up with a temporary
431 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]432
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]433<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]434 languages. There are keywords for different opcodes
435 ('<tt><a href="#i_add">add</a></tt>',
436 '<tt><a href="#i_bitcast">bitcast</a></tt>',
437 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
438 ('<tt><a href="#t_void">void</a></tt>',
439 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
440 reserved words cannot conflict with variable names, because none of them
441 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442
443<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]444 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]445
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]446<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]447
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]448<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]449%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]450</pre>
451
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]452<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]453
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]454<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]455%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456</pre>
457
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]458<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]460<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]461%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
462%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]463%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464</pre>
465
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]466<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
467 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]468
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]469<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]470 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]471 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]472
473 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]474 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]475
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]476 <li>Unnamed temporaries are numbered sequentially</li>
477</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]478
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]479<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]480 demonstrating instructions, we will follow an instruction with a comment that
481 defines the type and name of value produced. Comments are shown in italic
482 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]483
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]484</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]485
486<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]487<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]488<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]489<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]490<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]491<h3>
492 <a name="modulestructure">Module Structure</a>
493</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]494
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]495<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]496
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]497<p>LLVM programs are composed of "Module"s, each of which is a translation unit
498 of the input programs. Each module consists of functions, global variables,
499 and symbol table entries. Modules may be combined together with the LLVM
500 linker, which merges function (and global variable) definitions, resolves
501 forward declarations, and merges symbol table entries. Here is an example of
502 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]503
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]504<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]505<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]506<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]507
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]508<i>; External declaration of the puts function</i>&nbsp;
509<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]510
511<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]512define i32 @main() { <i>; i32()* </i>&nbsp;
513 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
514 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]515
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]516 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
517 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
518 <a href="#i_ret">ret</a> i32 0&nbsp;
519}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]520
521<i>; Named metadata</i>
522!1 = metadata !{i32 41}
523!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]524</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]525
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]526<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]527 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]528 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]529 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
530 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]531
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]532<p>In general, a module is made up of a list of global values, where both
533 functions and global variables are global values. Global values are
534 represented by a pointer to a memory location (in this case, a pointer to an
535 array of char, and a pointer to a function), and have one of the
536 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]537
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]538</div>
539
540<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]541<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]542 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]543</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]544
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]545<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]546
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]547<p>All Global Variables and Functions have one of the following types of
548 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]549
550<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]551 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]552 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
553 by objects in the current module. In particular, linking code into a
554 module with an private global value may cause the private to be renamed as
555 necessary to avoid collisions. Because the symbol is private to the
556 module, all references can be updated. This doesn't show up in any symbol
557 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]558
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]559 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]560 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
561 assembler and evaluated by the linker. Unlike normal strong symbols, they
562 are removed by the linker from the final linked image (executable or
563 dynamic library).</dd>
564
565 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
566 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
567 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
568 linker. The symbols are removed by the linker from the final linked image
569 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]570
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]571 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
572 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
573 of the object is not taken. For instance, functions that had an inline
574 definition, but the compiler decided not to inline it. Note,
575 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
576 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
577 visibility. The symbols are removed by the linker from the final linked
578 image (executable or dynamic library).</dd>
579
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]581 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]582 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
583 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]584
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]585 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]586 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]587 into the object file corresponding to the LLVM module. They exist to
588 allow inlining and other optimizations to take place given knowledge of
589 the definition of the global, which is known to be somewhere outside the
590 module. Globals with <tt>available_externally</tt> linkage are allowed to
591 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
592 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]593
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]594 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]595 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]596 the same name when linkage occurs. This can be used to implement
597 some forms of inline functions, templates, or other code which must be
598 generated in each translation unit that uses it, but where the body may
599 be overridden with a more definitive definition later. Unreferenced
600 <tt>linkonce</tt> globals are allowed to be discarded. Note that
601 <tt>linkonce</tt> linkage does not actually allow the optimizer to
602 inline the body of this function into callers because it doesn't know if
603 this definition of the function is the definitive definition within the
604 program or whether it will be overridden by a stronger definition.
605 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
606 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]607
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]608 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]609 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
610 <tt>linkonce</tt> linkage, except that unreferenced globals with
611 <tt>weak</tt> linkage may not be discarded. This is used for globals that
612 are declared "weak" in C source code.</dd>
613
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]614 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]615 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
616 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
617 global scope.
618 Symbols with "<tt>common</tt>" linkage are merged in the same way as
619 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]620 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]621 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]622 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
623 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]624
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]625
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]626 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]627 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]628 pointer to array type. When two global variables with appending linkage
629 are linked together, the two global arrays are appended together. This is
630 the LLVM, typesafe, equivalent of having the system linker append together
631 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]632
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]633 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]634 <dd>The semantics of this linkage follow the ELF object file model: the symbol
635 is weak until linked, if not linked, the symbol becomes null instead of
636 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]637
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]638 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
639 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]640 <dd>Some languages allow differing globals to be merged, such as two functions
641 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]642 that only equivalent globals are ever merged (the "one definition rule"
643 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]644 and <tt>weak_odr</tt> linkage types to indicate that the global will only
645 be merged with equivalent globals. These linkage types are otherwise the
646 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]647
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]648 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]649 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]650 visible, meaning that it participates in linkage and can be used to
651 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]652</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]653
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]654<p>The next two types of linkage are targeted for Microsoft Windows platform
655 only. They are designed to support importing (exporting) symbols from (to)
656 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]657
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]658<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]659 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]660 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]661 or variable via a global pointer to a pointer that is set up by the DLL
662 exporting the symbol. On Microsoft Windows targets, the pointer name is
663 formed by combining <code>__imp_</code> and the function or variable
664 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]665
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]666 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]667 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]668 pointer to a pointer in a DLL, so that it can be referenced with the
669 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
670 name is formed by combining <code>__imp_</code> and the function or
671 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]672</dl>
673
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]674<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
675 another module defined a "<tt>.LC0</tt>" variable and was linked with this
676 one, one of the two would be renamed, preventing a collision. Since
677 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
678 declarations), they are accessible outside of the current module.</p>
679
680<p>It is illegal for a function <i>declaration</i> to have any linkage type
681 other than "externally visible", <tt>dllimport</tt>
682 or <tt>extern_weak</tt>.</p>
683
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]684<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]685 or <tt>weak_odr</tt> linkages.</p>
686
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]687</div>
688
689<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]690<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]691 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]692</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]693
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]694<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]695
696<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]697 and <a href="#i_invoke">invokes</a> can all have an optional calling
698 convention specified for the call. The calling convention of any pair of
699 dynamic caller/callee must match, or the behavior of the program is
700 undefined. The following calling conventions are supported by LLVM, and more
701 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]702
703<dl>
704 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]705 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]706 specified) matches the target C calling conventions. This calling
707 convention supports varargs function calls and tolerates some mismatch in
708 the declared prototype and implemented declaration of the function (as
709 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]710
711 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]712 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]713 (e.g. by passing things in registers). This calling convention allows the
714 target to use whatever tricks it wants to produce fast code for the
715 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]716 (Application Binary Interface).
717 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]718 when this or the GHC convention is used.</a> This calling convention
719 does not support varargs and requires the prototype of all callees to
720 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]721
722 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]723 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]724 as possible under the assumption that the call is not commonly executed.
725 As such, these calls often preserve all registers so that the call does
726 not break any live ranges in the caller side. This calling convention
727 does not support varargs and requires the prototype of all callees to
728 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]729
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]730 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
731 <dd>This calling convention has been implemented specifically for use by the
732 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
733 It passes everything in registers, going to extremes to achieve this by
734 disabling callee save registers. This calling convention should not be
735 used lightly but only for specific situations such as an alternative to
736 the <em>register pinning</em> performance technique often used when
737 implementing functional programming languages.At the moment only X86
738 supports this convention and it has the following limitations:
739 <ul>
740 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
741 floating point types are supported.</li>
742 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
743 6 floating point parameters.</li>
744 </ul>
745 This calling convention supports
746 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
747 requires both the caller and callee are using it.
748 </dd>
749
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]750 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]751 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]752 target-specific calling conventions to be used. Target specific calling
753 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]754</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]755
756<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]757 support Pascal conventions or any other well-known target-independent
758 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]759
760</div>
761
762<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]763<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]764 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]765</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]766
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]767<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]768
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]769<p>All Global Variables and Functions have one of the following visibility
770 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]771
772<dl>
773 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]774 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]775 that the declaration is visible to other modules and, in shared libraries,
776 means that the declared entity may be overridden. On Darwin, default
777 visibility means that the declaration is visible to other modules. Default
778 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]779
780 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]781 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]782 object if they are in the same shared object. Usually, hidden visibility
783 indicates that the symbol will not be placed into the dynamic symbol
784 table, so no other module (executable or shared library) can reference it
785 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]786
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]787 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]788 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]789 the dynamic symbol table, but that references within the defining module
790 will bind to the local symbol. That is, the symbol cannot be overridden by
791 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]792</dl>
793
794</div>
795
796<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]797<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]798 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]799</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]800
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]801<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]802
803<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]804 it easier to read the IR and make the IR more condensed (particularly when
805 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]806
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]807<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]808%mytype = type { %mytype*, i32 }
809</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]810
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]811<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]812 "<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]813 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]814
815<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]816 and that you can therefore specify multiple names for the same type. This
817 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
818 uses structural typing, the name is not part of the type. When printing out
819 LLVM IR, the printer will pick <em>one name</em> to render all types of a
820 particular shape. This means that if you have code where two different
821 source types end up having the same LLVM type, that the dumper will sometimes
822 print the "wrong" or unexpected type. This is an important design point and
823 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]824
825</div>
826
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]827<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]828<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]829 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]830</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]831
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]832<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]833
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]834<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]835 instead of run-time. Global variables may optionally be initialized, may
836 have an explicit section to be placed in, and may have an optional explicit
837 alignment specified. A variable may be defined as "thread_local", which
838 means that it will not be shared by threads (each thread will have a
839 separated copy of the variable). A variable may be defined as a global
840 "constant," which indicates that the contents of the variable
841 will <b>never</b> be modified (enabling better optimization, allowing the
842 global data to be placed in the read-only section of an executable, etc).
843 Note that variables that need runtime initialization cannot be marked
844 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]845
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]846<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
847 constant, even if the final definition of the global is not. This capability
848 can be used to enable slightly better optimization of the program, but
849 requires the language definition to guarantee that optimizations based on the
850 'constantness' are valid for the translation units that do not include the
851 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]852
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]853<p>As SSA values, global variables define pointer values that are in scope
854 (i.e. they dominate) all basic blocks in the program. Global variables
855 always define a pointer to their "content" type because they describe a
856 region of memory, and all memory objects in LLVM are accessed through
857 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]858
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]859<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
860 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]861 like this can be merged with other constants if they have the same
862 initializer. Note that a constant with significant address <em>can</em>
863 be merged with a <tt>unnamed_addr</tt> constant, the result being a
864 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]865
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]866<p>A global variable may be declared to reside in a target-specific numbered
867 address space. For targets that support them, address spaces may affect how
868 optimizations are performed and/or what target instructions are used to
869 access the variable. The default address space is zero. The address space
870 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]871
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]872<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]873 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]874
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]875<p>An explicit alignment may be specified for a global, which must be a power
876 of 2. If not present, or if the alignment is set to zero, the alignment of
877 the global is set by the target to whatever it feels convenient. If an
878 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]879 alignment. Targets and optimizers are not allowed to over-align the global
880 if the global has an assigned section. In this case, the extra alignment
881 could be observable: for example, code could assume that the globals are
882 densely packed in their section and try to iterate over them as an array,
883 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]884
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]885<p>For example, the following defines a global in a numbered address space with
886 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]887
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]888<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]889@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]890</pre>
891
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]892</div>
893
894
895<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]896<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]897 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]898</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]899
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]900<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]901
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]902<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]903 optional <a href="#linkage">linkage type</a>, an optional
904 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]905 <a href="#callingconv">calling convention</a>,
906 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]907 <a href="#paramattrs">parameter attribute</a> for the return type, a function
908 name, a (possibly empty) argument list (each with optional
909 <a href="#paramattrs">parameter attributes</a>), optional
910 <a href="#fnattrs">function attributes</a>, an optional section, an optional
911 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
912 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]913
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]914<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
915 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]916 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]917 <a href="#callingconv">calling convention</a>,
918 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]919 <a href="#paramattrs">parameter attribute</a> for the return type, a function
920 name, a possibly empty list of arguments, an optional alignment, and an
921 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]922
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]923<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]924 (Control Flow Graph) for the function. Each basic block may optionally start
925 with a label (giving the basic block a symbol table entry), contains a list
926 of instructions, and ends with a <a href="#terminators">terminator</a>
927 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]928
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]929<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]930 executed on entrance to the function, and it is not allowed to have
931 predecessor basic blocks (i.e. there can not be any branches to the entry
932 block of a function). Because the block can have no predecessors, it also
933 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]934
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]935<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]936 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]937
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]938<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]939 the alignment is set to zero, the alignment of the function is set by the
940 target to whatever it feels convenient. If an explicit alignment is
941 specified, the function is forced to have at least that much alignment. All
942 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]943
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]944<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
945 be significant and two identical functions can be merged</p>.
946
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]947<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]948<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]949define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]950 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
951 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
952 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
953 [<a href="#gc">gc</a>] { ... }
954</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]955
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]956</div>
957
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]958<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]959<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]960 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]961</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]962
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]963<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]964
965<p>Aliases act as "second name" for the aliasee value (which can be either
966 function, global variable, another alias or bitcast of global value). Aliases
967 may have an optional <a href="#linkage">linkage type</a>, and an
968 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]969
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]970<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]971<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]972@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]973</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]974
975</div>
976
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]977<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]978<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]979 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]980</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]981
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]982<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]983
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]984<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]985 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]986 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]987
988<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]989<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]990; Some unnamed metadata nodes, which are referenced by the named metadata.
991!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]992!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]993!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]994; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]995!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]996</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]997
998</div>
999
1000<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1001<h3>
1002 <a name="paramattrs">Parameter Attributes</a>
1003</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1004
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1005<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1006
1007<p>The return type and each parameter of a function type may have a set of
1008 <i>parameter attributes</i> associated with them. Parameter attributes are
1009 used to communicate additional information about the result or parameters of
1010 a function. Parameter attributes are considered to be part of the function,
1011 not of the function type, so functions with different parameter attributes
1012 can have the same function type.</p>
1013
1014<p>Parameter attributes are simple keywords that follow the type specified. If
1015 multiple parameter attributes are needed, they are space separated. For
1016 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1017
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1018<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1019declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1020declare i32 @atoi(i8 zeroext)
1021declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1022</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1023
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1024<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1025 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1026
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1027<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1028
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1029<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1030 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1031 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1032 should be zero-extended to the extent required by the target's ABI (which
1033 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1034 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1035
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1036 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1038 should be sign-extended to the extent required by the target's ABI (which
1039 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1040 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1041
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1042 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1043 <dd>This indicates that this parameter or return value should be treated in a
1044 special target-dependent fashion during while emitting code for a function
1045 call or return (usually, by putting it in a register as opposed to memory,
1046 though some targets use it to distinguish between two different kinds of
1047 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1048
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1049 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1050 <dd><p>This indicates that the pointer parameter should really be passed by
1051 value to the function. The attribute implies that a hidden copy of the
1052 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1053 is made between the caller and the callee, so the callee is unable to
1054 modify the value in the callee. This attribute is only valid on LLVM
1055 pointer arguments. It is generally used to pass structs and arrays by
1056 value, but is also valid on pointers to scalars. The copy is considered
1057 to belong to the caller not the callee (for example,
1058 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1059 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1060 values.</p>
1061
1062 <p>The byval attribute also supports specifying an alignment with
1063 the align attribute. It indicates the alignment of the stack slot to
1064 form and the known alignment of the pointer specified to the call site. If
1065 the alignment is not specified, then the code generator makes a
1066 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1067
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1068 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1069 <dd>This indicates that the pointer parameter specifies the address of a
1070 structure that is the return value of the function in the source program.
1071 This pointer must be guaranteed by the caller to be valid: loads and
1072 stores to the structure may be assumed by the callee to not to trap. This
1073 may only be applied to the first parameter. This is not a valid attribute
1074 for return values. </dd>
1075
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1076 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1077 <dd>This indicates that pointer values
1078 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1079 value do not alias pointer values which are not <i>based</i> on it,
1080 ignoring certain "irrelevant" dependencies.
1081 For a call to the parent function, dependencies between memory
1082 references from before or after the call and from those during the call
1083 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1084 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1085 The caller shares the responsibility with the callee for ensuring that
1086 these requirements are met.
1087 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1088 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1089<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1090 Note that this definition of <tt>noalias</tt> is intentionally
1091 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1092 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1093<br>
1094 For function return values, C99's <tt>restrict</tt> is not meaningful,
1095 while LLVM's <tt>noalias</tt> is.
1096 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1097
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1098 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This indicates that the callee does not make any copies of the pointer
1100 that outlive the callee itself. This is not a valid attribute for return
1101 values.</dd>
1102
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1103 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1104 <dd>This indicates that the pointer parameter can be excised using the
1105 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1106 attribute for return values.</dd>
1107</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1108
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1109</div>
1110
1111<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1112<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1113 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1114</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1115
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1116<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1117
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1118<p>Each function may specify a garbage collector name, which is simply a
1119 string:</p>
1120
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1121<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1122define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1123</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1124
1125<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1126 collector which will cause the compiler to alter its output in order to
1127 support the named garbage collection algorithm.</p>
1128
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1129</div>
1130
1131<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1132<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1133 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1134</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1135
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1136<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1137
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1138<p>Function attributes are set to communicate additional information about a
1139 function. Function attributes are considered to be part of the function, not
1140 of the function type, so functions with different parameter attributes can
1141 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1142
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1143<p>Function attributes are simple keywords that follow the type specified. If
1144 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1145
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1146<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1147define void @f() noinline { ... }
1148define void @f() alwaysinline { ... }
1149define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1150define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1151</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1152
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1153<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1154 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1155 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1156 the backend should forcibly align the stack pointer. Specify the
1157 desired alignment, which must be a power of two, in parentheses.
1158
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1159 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1160 <dd>This attribute indicates that the inliner should attempt to inline this
1161 function into callers whenever possible, ignoring any active inlining size
1162 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1163
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1164 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1165 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1166 meaning the function can be patched and/or hooked even while it is
1167 loaded into memory. On x86, the function prologue will be preceded
1168 by six bytes of padding and will begin with a two-byte instruction.
1169 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1170 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1171
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1172 <dt><tt><b>nonlazybind</b></tt></dt>
1173 <dd>This attribute suppresses lazy symbol binding for the function. This
1174 may make calls to the function faster, at the cost of extra program
1175 startup time if the function is not called during program startup.</dd>
1176
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1177 <dt><tt><b>inlinehint</b></tt></dt>
1178 <dd>This attribute indicates that the source code contained a hint that inlining
1179 this function is desirable (such as the "inline" keyword in C/C++). It
1180 is just a hint; it imposes no requirements on the inliner.</dd>
1181
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1182 <dt><tt><b>naked</b></tt></dt>
1183 <dd>This attribute disables prologue / epilogue emission for the function.
1184 This can have very system-specific consequences.</dd>
1185
1186 <dt><tt><b>noimplicitfloat</b></tt></dt>
1187 <dd>This attributes disables implicit floating point instructions.</dd>
1188
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1189 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1190 <dd>This attribute indicates that the inliner should never inline this
1191 function in any situation. This attribute may not be used together with
1192 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1193
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1194 <dt><tt><b>noredzone</b></tt></dt>
1195 <dd>This attribute indicates that the code generator should not use a red
1196 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1197
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This function attribute indicates that the function never returns
1200 normally. This produces undefined behavior at runtime if the function
1201 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1202
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1203 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1204 <dd>This function attribute indicates that the function never returns with an
1205 unwind or exceptional control flow. If the function does unwind, its
1206 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1207
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1208 <dt><tt><b>optsize</b></tt></dt>
1209 <dd>This attribute suggests that optimization passes and code generator passes
1210 make choices that keep the code size of this function low, and otherwise
1211 do optimizations specifically to reduce code size.</dd>
1212
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1213 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1214 <dd>This attribute indicates that the function computes its result (or decides
1215 to unwind an exception) based strictly on its arguments, without
1216 dereferencing any pointer arguments or otherwise accessing any mutable
1217 state (e.g. memory, control registers, etc) visible to caller functions.
1218 It does not write through any pointer arguments
1219 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1220 changes any state visible to callers. This means that it cannot unwind
1221 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1222 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1223
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1224 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1225 <dd>This attribute indicates that the function does not write through any
1226 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1227 arguments) or otherwise modify any state (e.g. memory, control registers,
1228 etc) visible to caller functions. It may dereference pointer arguments
1229 and read state that may be set in the caller. A readonly function always
1230 returns the same value (or unwinds an exception identically) when called
1231 with the same set of arguments and global state. It cannot unwind an
1232 exception by calling the <tt>C++</tt> exception throwing methods, but may
1233 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1234
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1235 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1236 <dd>This attribute indicates that the function should emit a stack smashing
1237 protector. It is in the form of a "canary"&mdash;a random value placed on
1238 the stack before the local variables that's checked upon return from the
1239 function to see if it has been overwritten. A heuristic is used to
1240 determine if a function needs stack protectors or not.<br>
1241<br>
1242 If a function that has an <tt>ssp</tt> attribute is inlined into a
1243 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1244 function will have an <tt>ssp</tt> attribute.</dd>
1245
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1246 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1247 <dd>This attribute indicates that the function should <em>always</em> emit a
1248 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1249 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1250<br>
1251 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1252 function that doesn't have an <tt>sspreq</tt> attribute or which has
1253 an <tt>ssp</tt> attribute, then the resulting function will have
1254 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindola163d6752011-07-25 15:27:59 +0000[diff] [blame]1255
1256 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1257 <dd>This attribute indicates that the ABI being targeted requires that
1258 an unwind table entry be produce for this function even if we can
1259 show that no exceptions passes by it. This is normally the case for
1260 the ELF x86-64 abi, but it can be disabled for some compilation
1261 units.</dd>
1262
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1263</dl>
1264
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1265</div>
1266
1267<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1268<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1269 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1270</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1271
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1272<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1273
1274<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1275 the GCC "file scope inline asm" blocks. These blocks are internally
1276 concatenated by LLVM and treated as a single unit, but may be separated in
1277 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1278
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1279<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1280module asm "inline asm code goes here"
1281module asm "more can go here"
1282</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1283
1284<p>The strings can contain any character by escaping non-printable characters.
1285 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]1286 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1287
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1288<p>The inline asm code is simply printed to the machine code .s file when
1289 assembly code is generated.</p>
1290
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1291</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1292
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1293<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1294<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1295 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1296</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1297
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1298<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1299
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1300<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1301 data is to be laid out in memory. The syntax for the data layout is
1302 simply:</p>
1303
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1304<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1305target datalayout = "<i>layout specification</i>"
1306</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1307
1308<p>The <i>layout specification</i> consists of a list of specifications
1309 separated by the minus sign character ('-'). Each specification starts with
1310 a letter and may include other information after the letter to define some
1311 aspect of the data layout. The specifications accepted are as follows:</p>
1312
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1313<dl>
1314 <dt><tt>E</tt></dt>
1315 <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]1316 bits with the most significance have the lowest address location.</dd>
1317
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1318 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1319 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1320 the bits with the least significance have the lowest address
1321 location.</dd>
1322
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1323 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1324 <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]1325 <i>preferred</i> alignments. All sizes are in bits. Specifying
1326 the <i>pref</i> alignment is optional. If omitted, the
1327 preceding <tt>:</tt> should be omitted too.</dd>
1328
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1329 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1330 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1331 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1332
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1333 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1334 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1335 <i>size</i>.</dd>
1336
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1337 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1338 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1339 <i>size</i>. Only values of <i>size</i> that are supported by the target
1340 will work. 32 (float) and 64 (double) are supported on all targets;
1341 80 or 128 (different flavors of long double) are also supported on some
1342 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1343
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1344 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1345 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1346 <i>size</i>.</dd>
1347
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1348 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1349 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1350 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1351
1352 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1353 <dd>This specifies a set of native integer widths for the target CPU
1354 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1355 "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]1356 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1357 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1358</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1359
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1360<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1361 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1362 specifications in the <tt>datalayout</tt> keyword. The default specifications
1363 are given in this list:</p>
1364
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1365<ul>
1366 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1367 <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]1368 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1369 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1370 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1371 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1372 <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]1373 alignment of 64-bits</li>
1374 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1375 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1376 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1377 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1378 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1379 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1380</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1381
1382<p>When LLVM is determining the alignment for a given type, it uses the
1383 following rules:</p>
1384
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1385<ol>
1386 <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]1387 specification is used.</li>
1388
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1389 <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]1390 smallest integer type that is larger than the bitwidth of the sought type
1391 is used. If none of the specifications are larger than the bitwidth then
1392 the the largest integer type is used. For example, given the default
1393 specifications above, the i7 type will use the alignment of i8 (next
1394 largest) while both i65 and i256 will use the alignment of i64 (largest
1395 specified).</li>
1396
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1397 <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]1398 largest vector type that is smaller than the sought vector type will be
1399 used as a fall back. This happens because &lt;128 x double&gt; can be
1400 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1401</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1402
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1403</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1404
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1405<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1406<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1407 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1408</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1409
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1410<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1411
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1412<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1413with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1414is undefined. Pointer values are associated with address ranges
1415according to the following rules:</p>
1416
1417<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1418 <li>A pointer value is associated with the addresses associated with
1419 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1420 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1421 range of the variable's storage.</li>
1422 <li>The result value of an allocation instruction is associated with
1423 the address range of the allocated storage.</li>
1424 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1425 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1426 <li>An integer constant other than zero or a pointer value returned
1427 from a function not defined within LLVM may be associated with address
1428 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1429 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1430 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1431</ul>
1432
1433<p>A pointer value is <i>based</i> on another pointer value according
1434 to the following rules:</p>
1435
1436<ul>
1437 <li>A pointer value formed from a
1438 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1439 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1440 <li>The result value of a
1441 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1442 of the <tt>bitcast</tt>.</li>
1443 <li>A pointer value formed by an
1444 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1445 pointer values that contribute (directly or indirectly) to the
1446 computation of the pointer's value.</li>
1447 <li>The "<i>based</i> on" relationship is transitive.</li>
1448</ul>
1449
1450<p>Note that this definition of <i>"based"</i> is intentionally
1451 similar to the definition of <i>"based"</i> in C99, though it is
1452 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1453
1454<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1455<tt><a href="#i_load">load</a></tt> merely indicates the size and
1456alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1457interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1458<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1459and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1460
1461<p>Consequently, type-based alias analysis, aka TBAA, aka
1462<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1463LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1464additional information which specialized optimization passes may use
1465to implement type-based alias analysis.</p>
1466
1467</div>
1468
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1469<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1470<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1471 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1472</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1473
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1474<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1475
1476<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1477href="#i_store"><tt>store</tt></a>s, and <a
1478href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1479The optimizers must not change the number of volatile operations or change their
1480order of execution relative to other volatile operations. The optimizers
1481<i>may</i> change the order of volatile operations relative to non-volatile
1482operations. This is not Java's "volatile" and has no cross-thread
1483synchronization behavior.</p>
1484
1485</div>
1486
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1487<!-- ======================================================================= -->
1488<h3>
1489 <a name="memmodel">Memory Model for Concurrent Operations</a>
1490</h3>
1491
1492<div>
1493
1494<p>The LLVM IR does not define any way to start parallel threads of execution
1495or to register signal handlers. Nonetheless, there are platform-specific
1496ways to create them, and we define LLVM IR's behavior in their presence. This
1497model is inspired by the C++0x memory model.</p>
1498
1499<p>We define a <i>happens-before</i> partial order as the least partial order
1500that</p>
1501<ul>
1502 <li>Is a superset of single-thread program order, and</li>
1503 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1504 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1505 by platform-specific techniques, like pthread locks, thread
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame^]1506 creation, thread joining, etc., and by atomic instructions.
1507 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1508 </li>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1509</ul>
1510
1511<p>Note that program order does not introduce <i>happens-before</i> edges
1512between a thread and signals executing inside that thread.</p>
1513
1514<p>Every (defined) read operation (load instructions, memcpy, atomic
1515loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1516(defined) write operations (store instructions, atomic
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1517stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1518initialized globals are considered to have a write of the initializer which is
1519atomic and happens before any other read or write of the memory in question.
1520For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1521any write to the same byte, except:</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1522
1523<ul>
1524 <li>If <var>write<sub>1</sub></var> happens before
1525 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1526 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1527 does not see <var>write<sub>1</sub></var>.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1528 <li>If <var>R<sub>byte</sub></var> happens before <var>write<sub>3</var>,
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1529 then <var>R<sub>byte</sub></var> does not see
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1530 <var>write<sub>3</sub></var>.
1531</ul>
1532
1533<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1534<ul>
1535 <li>If there is no write to the same byte that happens before
1536 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1537 <tt>undef</tt> for that byte.
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1538 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1539 <var>R<sub>byte</sub></var> returns the value written by that
1540 write.</li>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1541 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1542 <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^]1543 values written. See the <a href="#ordering">Atomic Memory Ordering
1544 Constraints</a> section for additional constraints on how the choice
1545 is made.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1546 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1547</ul>
1548
1549<p><var>R</var> returns the value composed of the series of bytes it read.
1550This implies that some bytes within the value may be <tt>undef</tt>
1551<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1552defines the semantics of the operation; it doesn't mean that targets will
1553emit more than one instruction to read the series of bytes.</p>
1554
1555<p>Note that in cases where none of the atomic intrinsics are used, this model
1556places only one restriction on IR transformations on top of what is required
1557for single-threaded execution: introducing a store to a byte which might not
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1558otherwise be stored to can introduce undefined behavior. (Specifically, in
1559the case where another thread might write to and read from an address,
1560introducing a store can change a load that may see exactly one write into
1561a load that may see multiple writes.)</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1562
1563<!-- FIXME: This model assumes all targets where concurrency is relevant have
1564a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1565none of the backends currently in the tree fall into this category; however,
1566there might be targets which care. If there are, we want a paragraph
1567like the following:
1568
1569Targets may specify that stores narrower than a certain width are not
1570available; on such a target, for the purposes of this model, treat any
1571non-atomic write with an alignment or width less than the minimum width
1572as if it writes to the relevant surrounding bytes.
1573-->
1574
1575</div>
1576
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame^]1577<!-- ======================================================================= -->
1578<div class="doc_subsection">
1579 <a name="ordering">Atomic Memory Ordering Constraints</a>
1580</div>
1581
1582<div class="doc_text">
1583
1584<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
1585<a href="#i_atomicrmw"><code>atomicrmw</code></a>, and
1586<a href="#i_fence"><code>fence</code></a>) take an ordering parameter
1587that determines which other atomic instructions on the same address they
1588<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1589but are somewhat more colloquial. If these descriptions aren't precise enough,
1590check those specs. <a href="#i_fence"><code>fence</code></a> instructions
1591treat these orderings somewhat differently since they don't take an address.
1592See that instruction's documentation for details.</p>
1593
1594<!-- FIXME Note atomic load+store here once those get added. -->
1595
1596<dl>
1597<!-- FIXME: unordered is intended to be used for atomic load and store;
1598it isn't allowed for any instruction yet. -->
1599<dt><code>unordered</code></dt>
1600<dd>The set of values that can be read is governed by the happens-before
1601partial order. A value cannot be read unless some operation wrote it.
1602This is intended to provide a guarantee strong enough to model Java's
1603non-volatile shared variables. This ordering cannot be specified for
1604read-modify-write operations; it is not strong enough to make them atomic
1605in any interesting way.</dd>
1606<dt><code>monotonic</code></dt>
1607<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1608total order for modifications by <code>monotonic</code> operations on each
1609address. All modification orders must be compatible with the happens-before
1610order. There is no guarantee that the modification orders can be combined to
1611a global total order for the whole program (and this often will not be
1612possible). The read in an atomic read-modify-write operation
1613(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1614<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1615reads the value in the modification order immediately before the value it
1616writes. If one atomic read happens before another atomic read of the same
1617address, the later read must see the same value or a later value in the
1618address's modification order. This disallows reordering of
1619<code>monotonic</code> (or stronger) operations on the same address. If an
1620address is written <code>monotonic</code>ally by one thread, and other threads
1621<code>monotonic</code>ally read that address repeatedly, the other threads must
1622eventually see the write. This is intended to model C++'s relaxed atomic
1623variables.</dd>
1624<dt><code>acquire</code></dt>
1625<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1626reads a value written by a <code>release</code> atomic operation, it
1627<i>synchronizes-with</i> that operation.</dd>
1628<dt><code>release</code></dt>
1629<dd>In addition to the guarantees of <code>monotonic</code>,
1630a <i>synchronizes-with</i> edge may be formed by an <code>acquire</code>
1631operation.</dd>
1632<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
1633<code>acquire</code> and <code>release</code> operation on its address.</dd>
1634<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1635<dd>In addition to the guarantees of <code>acq_rel</code>
1636(<code>acquire</code> for an operation which only reads, <code>release</code>
1637for an operation which only writes), there is a global total order on all
1638sequentially-consistent operations on all addresses, which is consistent with
1639the <i>happens-before</i> partial order and with the modification orders of
1640all the affected addresses. Each sequentially-consistent read sees the last
1641preceding write to the same address in this global order. This is intended
1642to model C++'s sequentially-consistent atomic variables and Java's volatile
1643shared variables.</dd>
1644</dl>
1645
1646<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1647it only <i>synchronizes with</i> or participates in modification and seq_cst
1648total orderings with other operations running in the same thread (for example,
1649in signal handlers).</p>
1650
1651</div>
1652
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1653</div>
1654
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1655<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1656<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1657<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1658
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1659<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1660
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1661<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1662 intermediate representation. Being typed enables a number of optimizations
1663 to be performed on the intermediate representation directly, without having
1664 to do extra analyses on the side before the transformation. A strong type
1665 system makes it easier to read the generated code and enables novel analyses
1666 and transformations that are not feasible to perform on normal three address
1667 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1668
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1669<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1670<h3>
1671 <a name="t_classifications">Type Classifications</a>
1672</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1673
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1674<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1675
1676<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1677
1678<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1679 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1680 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1681 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1682 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1683 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1684 </tr>
1685 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1686 <td><a href="#t_floating">floating point</a></td>
1687 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1688 </tr>
1689 <tr>
1690 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1691 <td><a href="#t_integer">integer</a>,
1692 <a href="#t_floating">floating point</a>,
1693 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1694 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1695 <a href="#t_struct">structure</a>,
1696 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1697 <a href="#t_label">label</a>,
1698 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1699 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1700 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1701 <tr>
1702 <td><a href="#t_primitive">primitive</a></td>
1703 <td><a href="#t_label">label</a>,
1704 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1705 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1706 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1707 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1708 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1709 </tr>
1710 <tr>
1711 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1712 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1713 <a href="#t_function">function</a>,
1714 <a href="#t_pointer">pointer</a>,
1715 <a href="#t_struct">structure</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1716 <a href="#t_vector">vector</a>,
1717 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1718 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1719 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1720 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1721</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1722
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1723<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1724 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1725 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1726
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1727</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1729<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1730<h3>
1731 <a name="t_primitive">Primitive Types</a>
1732</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1733
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1734<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1735
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1736<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1737 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1738
1739<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1740<h4>
1741 <a name="t_integer">Integer Type</a>
1742</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1743
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1744<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1745
1746<h5>Overview:</h5>
1747<p>The integer type is a very simple type that simply specifies an arbitrary
1748 bit width for the integer type desired. Any bit width from 1 bit to
1749 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1750
1751<h5>Syntax:</h5>
1752<pre>
1753 iN
1754</pre>
1755
1756<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1757 value.</p>
1758
1759<h5>Examples:</h5>
1760<table class="layout">
1761 <tr class="layout">
1762 <td class="left"><tt>i1</tt></td>
1763 <td class="left">a single-bit integer.</td>
1764 </tr>
1765 <tr class="layout">
1766 <td class="left"><tt>i32</tt></td>
1767 <td class="left">a 32-bit integer.</td>
1768 </tr>
1769 <tr class="layout">
1770 <td class="left"><tt>i1942652</tt></td>
1771 <td class="left">a really big integer of over 1 million bits.</td>
1772 </tr>
1773</table>
1774
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1775</div>
1776
1777<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1778<h4>
1779 <a name="t_floating">Floating Point Types</a>
1780</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1781
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1782<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1783
1784<table>
1785 <tbody>
1786 <tr><th>Type</th><th>Description</th></tr>
1787 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1788 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1789 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1790 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1791 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1792 </tbody>
1793</table>
1794
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1795</div>
1796
1797<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1798<h4>
1799 <a name="t_x86mmx">X86mmx Type</a>
1800</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1801
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1802<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1803
1804<h5>Overview:</h5>
1805<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>
1806
1807<h5>Syntax:</h5>
1808<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1809 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1810</pre>
1811
1812</div>
1813
1814<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1815<h4>
1816 <a name="t_void">Void Type</a>
1817</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1818
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1819<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1820
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1821<h5>Overview:</h5>
1822<p>The void type does not represent any value and has no size.</p>
1823
1824<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1825<pre>
1826 void
1827</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1828
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1829</div>
1830
1831<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1832<h4>
1833 <a name="t_label">Label Type</a>
1834</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1835
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1836<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1837
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1838<h5>Overview:</h5>
1839<p>The label type represents code labels.</p>
1840
1841<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1842<pre>
1843 label
1844</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1845
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1846</div>
1847
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1848<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1849<h4>
1850 <a name="t_metadata">Metadata Type</a>
1851</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1852
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1853<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1854
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1855<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1856<p>The metadata type represents embedded metadata. No derived types may be
1857 created from metadata except for <a href="#t_function">function</a>
1858 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1859
1860<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1861<pre>
1862 metadata
1863</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1864
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1865</div>
1866
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1867</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1868
1869<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1870<h3>
1871 <a name="t_derived">Derived Types</a>
1872</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1873
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1874<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1875
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1876<p>The real power in LLVM comes from the derived types in the system. This is
1877 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1878 useful types. Each of these types contain one or more element types which
1879 may be a primitive type, or another derived type. For example, it is
1880 possible to have a two dimensional array, using an array as the element type
1881 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1882
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1883</div>
1884
1885
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1886<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1887<h4>
1888 <a name="t_aggregate">Aggregate Types</a>
1889</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1890
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1891<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1892
1893<p>Aggregate Types are a subset of derived types that can contain multiple
1894 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1895 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1896 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1897
1898</div>
1899
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1900<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1901<h4>
1902 <a name="t_array">Array Type</a>
1903</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1904
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1905<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1906
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1907<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1908<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1909 sequentially in memory. The array type requires a size (number of elements)
1910 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1911
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1912<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1913<pre>
1914 [&lt;# elements&gt; x &lt;elementtype&gt;]
1915</pre>
1916
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1917<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1918 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1919
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1920<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1921<table class="layout">
1922 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1923 <td class="left"><tt>[40 x i32]</tt></td>
1924 <td class="left">Array of 40 32-bit integer values.</td>
1925 </tr>
1926 <tr class="layout">
1927 <td class="left"><tt>[41 x i32]</tt></td>
1928 <td class="left">Array of 41 32-bit integer values.</td>
1929 </tr>
1930 <tr class="layout">
1931 <td class="left"><tt>[4 x i8]</tt></td>
1932 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1933 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1934</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1935<p>Here are some examples of multidimensional arrays:</p>
1936<table class="layout">
1937 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1938 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1939 <td class="left">3x4 array of 32-bit integer values.</td>
1940 </tr>
1941 <tr class="layout">
1942 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1943 <td class="left">12x10 array of single precision floating point values.</td>
1944 </tr>
1945 <tr class="layout">
1946 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1947 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1948 </tr>
1949</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1950
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1951<p>There is no restriction on indexing beyond the end of the array implied by
1952 a static type (though there are restrictions on indexing beyond the bounds
1953 of an allocated object in some cases). This means that single-dimension
1954 'variable sized array' addressing can be implemented in LLVM with a zero
1955 length array type. An implementation of 'pascal style arrays' in LLVM could
1956 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1957
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1958</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1959
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1960<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1961<h4>
1962 <a name="t_function">Function Type</a>
1963</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1964
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1965<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1966
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1967<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1968<p>The function type can be thought of as a function signature. It consists of
1969 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]1970 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1971
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1972<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1973<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1974 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1975</pre>
1976
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1977<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]1978 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1979 which indicates that the function takes a variable number of arguments.
1980 Variable argument functions can access their arguments with
1981 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1982 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1983 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1984
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1985<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1986<table class="layout">
1987 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1988 <td class="left"><tt>i32 (i32)</tt></td>
1989 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1990 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1991 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1992 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1993 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1994 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1995 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1996 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1997 </td>
1998 </tr><tr class="layout">
1999 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2000 <td class="left">A vararg function that takes at least one
2001 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2002 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]2003 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2004 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2005 </tr><tr class="layout">
2006 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]2007 <td class="left">A function taking an <tt>i32</tt>, returning a
2008 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2009 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2010 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2011</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2012
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2013</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2014
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2015<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2016<h4>
2017 <a name="t_struct">Structure Type</a>
2018</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2019
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2020<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2021
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2022<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2023<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2024 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]2025
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]2026<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2027 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2028 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2029 Structures in registers are accessed using the
2030 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2031 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2032
2033<p>Structures may optionally be "packed" structures, which indicate that the
2034 alignment of the struct is one byte, and that there is no padding between
2035 the elements. In non-packed structs, padding between field types is defined
2036 by the target data string to match the underlying processor.</p>
2037
2038<p>Structures can either be "anonymous" or "named". An anonymous structure is
2039 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
2040 are always defined at the top level with a name. Anonmyous types are uniqued
2041 by their contents and can never be recursive since there is no way to write
2042 one. Named types can be recursive.
2043</p>
2044
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2045<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2046<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2047 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
2048 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2049</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2050
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2051<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2052<table class="layout">
2053 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2054 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2055 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2056 </tr>
2057 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2058 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2059 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2060 second element is a <a href="#t_pointer">pointer</a> to a
2061 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2062 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2063 </tr>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2064 <tr class="layout">
2065 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2066 <td class="left">A packed struct known to be 5 bytes in size.</td>
2067 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2068</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2069
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2070</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2071
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2072<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2073<h4>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2074 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2075</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2076
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2077<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2078
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2079<h5>Overview:</h5>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2080<p>Opaque structure types are used to represent named structure types that do
2081 not have a body specified. This corresponds (for example) to the C notion of
2082 a forward declared structure.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2083
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2084<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2085<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2086 %X = type opaque
2087 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2088</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2089
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2090<h5>Examples:</h5>
2091<table class="layout">
2092 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2093 <td class="left"><tt>opaque</tt></td>
2094 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2095 </tr>
2096</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2097
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2098</div>
2099
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2100
2101
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2102<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2103<h4>
2104 <a name="t_pointer">Pointer Type</a>
2105</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2106
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2107<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2108
2109<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]2110<p>The pointer type is used to specify memory locations.
2111 Pointers are commonly used to reference objects in memory.</p>
2112
2113<p>Pointer types may have an optional address space attribute defining the
2114 numbered address space where the pointed-to object resides. The default
2115 address space is number zero. The semantics of non-zero address
2116 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2117
2118<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2119 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2120
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2121<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2122<pre>
2123 &lt;type&gt; *
2124</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2125
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2126<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2127<table class="layout">
2128 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2129 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2130 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2131 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2132 </tr>
2133 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]2134 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2135 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2136 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2137 <tt>i32</tt>.</td>
2138 </tr>
2139 <tr class="layout">
2140 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2141 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2142 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2143 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2144</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2145
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2146</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2147
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2148<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2149<h4>
2150 <a name="t_vector">Vector Type</a>
2151</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2152
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2153<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2154
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2155<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2156<p>A vector type is a simple derived type that represents a vector of elements.
2157 Vector types are used when multiple primitive data are operated in parallel
2158 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]2159 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2160 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2161
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2162<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2163<pre>
2164 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2165</pre>
2166
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]2167<p>The number of elements is a constant integer value larger than 0; elementtype
2168 may be any integer or floating point type. Vectors of size zero are not
2169 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2170
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2171<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2172<table class="layout">
2173 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2174 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2175 <td class="left">Vector of 4 32-bit integer values.</td>
2176 </tr>
2177 <tr class="layout">
2178 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2179 <td class="left">Vector of 8 32-bit floating-point values.</td>
2180 </tr>
2181 <tr class="layout">
2182 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2183 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2184 </tr>
2185</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2186
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2187</div>
2188
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2189<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2190<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2191<!-- *********************************************************************** -->
2192
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2193<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2194
2195<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2196 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2197
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2198<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2199<h3>
2200 <a name="simpleconstants">Simple Constants</a>
2201</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2202
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2203<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2204
2205<dl>
2206 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2207 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2208 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2209
2210 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2211 <dd>Standard integers (such as '4') are constants of
2212 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2213 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2214
2215 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2216 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2217 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2218 notation (see below). The assembler requires the exact decimal value of a
2219 floating-point constant. For example, the assembler accepts 1.25 but
2220 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2221 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2222
2223 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2224 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2225 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2226</dl>
2227
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2228<p>The one non-intuitive notation for constants is the hexadecimal form of
2229 floating point constants. For example, the form '<tt>double
2230 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2231 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2232 constants are required (and the only time that they are generated by the
2233 disassembler) is when a floating point constant must be emitted but it cannot
2234 be represented as a decimal floating point number in a reasonable number of
2235 digits. For example, NaN's, infinities, and other special values are
2236 represented in their IEEE hexadecimal format so that assembly and disassembly
2237 do not cause any bits to change in the constants.</p>
2238
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2239<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2240 represented using the 16-digit form shown above (which matches the IEEE754
2241 representation for double); float values must, however, be exactly
2242 representable as IEE754 single precision. Hexadecimal format is always used
2243 for long double, and there are three forms of long double. The 80-bit format
2244 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2245 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2246 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2247 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2248 currently supported target uses this format. Long doubles will only work if
2249 they match the long double format on your target. All hexadecimal formats
2250 are big-endian (sign bit at the left).</p>
2251
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2252<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2253</div>
2254
2255<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2256<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2257<a name="aggregateconstants"></a> <!-- old anchor -->
2258<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2259</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2260
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2261<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2262
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2263<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2264 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2265
2266<dl>
2267 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2268 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2269 type definitions (a comma separated list of elements, surrounded by braces
2270 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2271 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2272 Structure constants must have <a href="#t_struct">structure type</a>, and
2273 the number and types of elements must match those specified by the
2274 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2275
2276 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2277 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2278 definitions (a comma separated list of elements, surrounded by square
2279 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2280 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2281 the number and types of elements must match those specified by the
2282 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2283
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2284 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2285 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2286 definitions (a comma separated list of elements, surrounded by
2287 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2288 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2289 have <a href="#t_vector">vector type</a>, and the number and types of
2290 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2291
2292 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2293 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2294 value to zero of <em>any</em> type, including scalar and
2295 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2296 This is often used to avoid having to print large zero initializers
2297 (e.g. for large arrays) and is always exactly equivalent to using explicit
2298 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2299
2300 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2301 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2302 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2303 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2304 be interpreted as part of the instruction stream, metadata is a place to
2305 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2306</dl>
2307
2308</div>
2309
2310<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2311<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2312 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2313</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2314
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2315<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2316
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2317<p>The addresses of <a href="#globalvars">global variables</a>
2318 and <a href="#functionstructure">functions</a> are always implicitly valid
2319 (link-time) constants. These constants are explicitly referenced when
2320 the <a href="#identifiers">identifier for the global</a> is used and always
2321 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2322 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2323
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2324<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2325@X = global i32 17
2326@Y = global i32 42
2327@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2328</pre>
2329
2330</div>
2331
2332<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2333<h3>
2334 <a name="undefvalues">Undefined Values</a>
2335</h3>
2336
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2337<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2338
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2339<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]2340 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2341 Undefined values may be of any type (other than '<tt>label</tt>'
2342 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2343
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2344<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2345 program is well defined no matter what value is used. This gives the
2346 compiler more freedom to optimize. Here are some examples of (potentially
2347 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2348
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2349
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2350<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2351 %A = add %X, undef
2352 %B = sub %X, undef
2353 %C = xor %X, undef
2354Safe:
2355 %A = undef
2356 %B = undef
2357 %C = undef
2358</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2359
2360<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]2361 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]2362
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2363<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2364 %A = or %X, undef
2365 %B = and %X, undef
2366Safe:
2367 %A = -1
2368 %B = 0
2369Unsafe:
2370 %A = undef
2371 %B = undef
2372</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2373
2374<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2375 For example, if <tt>%X</tt> has a zero bit, then the output of the
2376 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2377 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2378 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2379 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2380 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2381 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2382 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2383
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2384<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2385 %A = select undef, %X, %Y
2386 %B = select undef, 42, %Y
2387 %C = select %X, %Y, undef
2388Safe:
2389 %A = %X (or %Y)
2390 %B = 42 (or %Y)
2391 %C = %Y
2392Unsafe:
2393 %A = undef
2394 %B = undef
2395 %C = undef
2396</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2397
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2398<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2399 branch) conditions can go <em>either way</em>, but they have to come from one
2400 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2401 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2402 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2403 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2404 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2405 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2406
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2407<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2408 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2409
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2410 %B = undef
2411 %C = xor %B, %B
2412
2413 %D = undef
2414 %E = icmp lt %D, 4
2415 %F = icmp gte %D, 4
2416
2417Safe:
2418 %A = undef
2419 %B = undef
2420 %C = undef
2421 %D = undef
2422 %E = undef
2423 %F = undef
2424</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2425
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2426<p>This example points out that two '<tt>undef</tt>' operands are not
2427 necessarily the same. This can be surprising to people (and also matches C
2428 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2429 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2430 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2431 its value over its "live range". This is true because the variable doesn't
2432 actually <em>have a live range</em>. Instead, the value is logically read
2433 from arbitrary registers that happen to be around when needed, so the value
2434 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2435 need to have the same semantics or the core LLVM "replace all uses with"
2436 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2437
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2438<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2439 %A = fdiv undef, %X
2440 %B = fdiv %X, undef
2441Safe:
2442 %A = undef
2443b: unreachable
2444</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2445
2446<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2447 value</em> and <em>undefined behavior</em>. An undefined value (like
2448 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2449 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2450 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2451 defined on SNaN's. However, in the second example, we can make a more
2452 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2453 arbitrary value, we are allowed to assume that it could be zero. Since a
2454 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2455 the operation does not execute at all. This allows us to delete the divide and
2456 all code after it. Because the undefined operation "can't happen", the
2457 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2458
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2459<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2460a: store undef -> %X
2461b: store %X -> undef
2462Safe:
2463a: &lt;deleted&gt;
2464b: unreachable
2465</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2466
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2467<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2468 undefined value can be assumed to not have any effect; we can assume that the
2469 value is overwritten with bits that happen to match what was already there.
2470 However, a store <em>to</em> an undefined location could clobber arbitrary
2471 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2472
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2473</div>
2474
2475<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2476<h3>
2477 <a name="trapvalues">Trap Values</a>
2478</h3>
2479
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2480<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2481
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2482<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2483 instead of representing an unspecified bit pattern, they represent the
2484 fact that an instruction or constant expression which cannot evoke side
2485 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2486 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2487
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2488<p>There is currently no way of representing a trap value in the IR; they
Dan Gohmanac355aa2010-05-03 14:51:43 +0000[diff] [blame]2489 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2490 <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]2491
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2492<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2493
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2494<ul>
2495<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2496 their operands.</li>
2497
2498<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2499 to their dynamic predecessor basic block.</li>
2500
2501<li>Function arguments depend on the corresponding actual argument values in
2502 the dynamic callers of their functions.</li>
2503
2504<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2505 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2506 control back to them.</li>
2507
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2508<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2509 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2510 or exception-throwing call instructions that dynamically transfer control
2511 back to them.</li>
2512
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2513<li>Non-volatile loads and stores depend on the most recent stores to all of the
2514 referenced memory addresses, following the order in the IR
2515 (including loads and stores implied by intrinsics such as
2516 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2517
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2518<!-- TODO: In the case of multiple threads, this only applies if the store
2519 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2520
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2521<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2522
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2523<li>An instruction with externally visible side effects depends on the most
2524 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2525 the order in the IR. (This includes
2526 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2527
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2528<li>An instruction <i>control-depends</i> on a
2529 <a href="#terminators">terminator instruction</a>
2530 if the terminator instruction has multiple successors and the instruction
2531 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2532 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2533
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2534<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2535 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2536 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2537 successor.</li>
2538
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2539<li>Dependence is transitive.</li>
2540
2541</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2542
2543<p>Whenever a trap value is generated, all values which depend on it evaluate
2544 to trap. If they have side effects, the evoke their side effects as if each
2545 operand with a trap value were undef. If they have externally-visible side
2546 effects, the behavior is undefined.</p>
2547
2548<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2549
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2550<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2551entry:
2552 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2553 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2554 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2555 store i32 0, i32* %trap_yet_again ; undefined behavior
2556
2557 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2558 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2559
2560 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2561
2562 %narrowaddr = bitcast i32* @g to i16*
2563 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2564 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2565 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2566
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2567 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2568 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2569
2570true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2571 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2572 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2573 br label %end
2574
2575end:
2576 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2577 ; Both edges into this PHI are
2578 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2579 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2580
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2581 volatile store i32 0, i32* @g ; This would depend on the store in %true
2582 ; if %cmp is true, or the store in %entry
2583 ; otherwise, so this is undefined behavior.
2584
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2585 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2586 ; The same branch again, but this time the
2587 ; true block doesn't have side effects.
2588
2589second_true:
2590 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2591 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2592
2593second_end:
2594 volatile store i32 0, i32* @g ; This time, the instruction always depends
2595 ; on the store in %end. Also, it is
2596 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2597 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2598 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2599</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2600
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2601</div>
2602
2603<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2604<h3>
2605 <a name="blockaddress">Addresses of Basic Blocks</a>
2606</h3>
2607
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2608<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2609
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2610<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2611
2612<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2613 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2614 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2615
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2616<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2617 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2618 comparisons against null. Pointer equality tests between labels addresses
2619 results in undefined behavior &mdash; though, again, comparison against null
2620 is ok, and no label is equal to the null pointer. This may be passed around
2621 as an opaque pointer sized value as long as the bits are not inspected. This
2622 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2623 long as the original value is reconstituted before the <tt>indirectbr</tt>
2624 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2625
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2626<p>Finally, some targets may provide defined semantics when using the value as
2627 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2628
2629</div>
2630
2631
2632<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2633<h3>
2634 <a name="constantexprs">Constant Expressions</a>
2635</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2636
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2637<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2638
2639<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2640 to be used as constants. Constant expressions may be of
2641 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2642 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2643 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2644
2645<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2646 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2647 <dd>Truncate a constant to another type. The bit size of CST must be larger
2648 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2649
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2650 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2651 <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]2652 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2653
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2654 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2655 <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]2656 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2657
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2658 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2659 <dd>Truncate a floating point constant to another floating point type. The
2660 size of CST must be larger than the size of TYPE. Both types must be
2661 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2662
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2663 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2664 <dd>Floating point extend a constant to another type. The size of CST must be
2665 smaller or equal to the size of TYPE. Both types must be floating
2666 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2667
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2668 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2669 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2670 constant. TYPE must be a scalar or vector integer type. CST must be of
2671 scalar or vector floating point type. Both CST and TYPE must be scalars,
2672 or vectors of the same number of elements. If the value won't fit in the
2673 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2674
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2675 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2676 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2677 constant. TYPE must be a scalar or vector integer type. CST must be of
2678 scalar or vector floating point type. Both CST and TYPE must be scalars,
2679 or vectors of the same number of elements. If the value won't fit in the
2680 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2681
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2682 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2683 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2684 constant. TYPE must be a scalar or vector floating point type. CST must be
2685 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2686 vectors of the same number of elements. If the value won't fit in the
2687 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2688
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2689 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2690 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2691 constant. TYPE must be a scalar or vector floating point type. CST must be
2692 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2693 vectors of the same number of elements. If the value won't fit in the
2694 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2695
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2696 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2697 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2698 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2699 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2700 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2701
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2702 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2703 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2704 type. CST must be of integer type. The CST value is zero extended,
2705 truncated, or unchanged to make it fit in a pointer size. This one is
2706 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2707
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2708 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2709 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2710 are the same as those for the <a href="#i_bitcast">bitcast
2711 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2712
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2713 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2714 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2715 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2716 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2717 instruction, the index list may have zero or more indexes, which are
2718 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2719
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2720 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2721 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2722
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2723 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2724 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2725
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2726 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2727 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2728
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2729 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2730 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2731 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2732
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2733 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2734 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2735 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2736
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2737 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2738 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2739 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2740
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2741 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2742 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2743 constants. The index list is interpreted in a similar manner as indices in
2744 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2745 index value must be specified.</dd>
2746
2747 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2748 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2749 constants. The index list is interpreted in a similar manner as indices in
2750 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2751 index value must be specified.</dd>
2752
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2753 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2754 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2755 be any of the <a href="#binaryops">binary</a>
2756 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2757 on operands are the same as those for the corresponding instruction
2758 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2759</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2760
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2761</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2762
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2763</div>
2764
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2765<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2766<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2767<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2768<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2769<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2770<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2771<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2772</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2773
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2774<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2775
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2776<p>LLVM supports inline assembler expressions (as opposed
2777 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2778 a special value. This value represents the inline assembler as a string
2779 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2780 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2781 expression has side effects, and a flag indicating whether the function
2782 containing the asm needs to align its stack conservatively. An example
2783 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2784
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2785<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2786i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2787</pre>
2788
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2789<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2790 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2791 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2792
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2793<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2794%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]2795</pre>
2796
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2797<p>Inline asms with side effects not visible in the constraint list must be
2798 marked as having side effects. This is done through the use of the
2799 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2800
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2801<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2802call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2803</pre>
2804
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2805<p>In some cases inline asms will contain code that will not work unless the
2806 stack is aligned in some way, such as calls or SSE instructions on x86,
2807 yet will not contain code that does that alignment within the asm.
2808 The compiler should make conservative assumptions about what the asm might
2809 contain and should generate its usual stack alignment code in the prologue
2810 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2811
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2812<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2813call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2814</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2815
2816<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2817 first.</p>
2818
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2819<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2820 documented here. Constraints on what can be done (e.g. duplication, moving,
2821 etc need to be documented). This is probably best done by reference to
2822 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2823
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2824<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2825<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2826</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2827
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2828<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2829
2830<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2831 attached to it that contains a list of constant integers. If present, the
2832 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2833 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2834 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2835 source code that produced it. For example:</p>
2836
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2837<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2838call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2839...
2840!42 = !{ i32 1234567 }
2841</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2842
2843<p>It is up to the front-end to make sense of the magic numbers it places in the
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2844 IR. If the MDNode contains multiple constants, the code generator will use
2845 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]2846
2847</div>
2848
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2849</div>
2850
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2851<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2852<h3>
2853 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2854</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2855
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2856<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2857
2858<p>LLVM IR allows metadata to be attached to instructions in the program that
2859 can convey extra information about the code to the optimizers and code
2860 generator. One example application of metadata is source-level debug
2861 information. There are two metadata primitives: strings and nodes. All
2862 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2863 preceding exclamation point ('<tt>!</tt>').</p>
2864
2865<p>A metadata string is a string surrounded by double quotes. It can contain
2866 any character by escaping non-printable characters with "\xx" where "xx" is
2867 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2868
2869<p>Metadata nodes are represented with notation similar to structure constants
2870 (a comma separated list of elements, surrounded by braces and preceded by an
2871 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2872 10}</tt>". Metadata nodes can have any values as their operand.</p>
2873
2874<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2875 metadata nodes, which can be looked up in the module symbol table. For
2876 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2877
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2878<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2879 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2880
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2881<div class="doc_code">
2882<pre>
2883call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2884</pre>
2885</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2886
2887<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2888 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2889
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2890<div class="doc_code">
2891<pre>
2892%indvar.next = add i64 %indvar, 1, !dbg !21
2893</pre>
2894</div>
2895
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2896</div>
2897
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2898</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2899
2900<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2901<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2902 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2903</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2904<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2905<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2906<p>LLVM has a number of "magic" global variables that contain data that affect
2907code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2908of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2909section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2910by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2911
2912<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2913<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2914<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2915</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2916
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2917<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2918
2919<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2920href="#linkage_appending">appending linkage</a>. This array contains a list of
2921pointers to global variables and functions which may optionally have a pointer
2922cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2923
2924<pre>
2925 @X = global i8 4
2926 @Y = global i32 123
2927
2928 @llvm.used = appending global [2 x i8*] [
2929 i8* @X,
2930 i8* bitcast (i32* @Y to i8*)
2931 ], section "llvm.metadata"
2932</pre>
2933
2934<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2935compiler, assembler, and linker are required to treat the symbol as if there is
2936a reference to the global that it cannot see. For example, if a variable has
2937internal linkage and no references other than that from the <tt>@llvm.used</tt>
2938list, it cannot be deleted. This is commonly used to represent references from
2939inline asms and other things the compiler cannot "see", and corresponds to
2940"attribute((used))" in GNU C.</p>
2941
2942<p>On some targets, the code generator must emit a directive to the assembler or
2943object file to prevent the assembler and linker from molesting the symbol.</p>
2944
2945</div>
2946
2947<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2948<h3>
2949 <a name="intg_compiler_used">
2950 The '<tt>llvm.compiler.used</tt>' Global Variable
2951 </a>
2952</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2953
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2954<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2955
2956<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2957<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2958touching the symbol. On targets that support it, this allows an intelligent
2959linker to optimize references to the symbol without being impeded as it would be
2960by <tt>@llvm.used</tt>.</p>
2961
2962<p>This is a rare construct that should only be used in rare circumstances, and
2963should not be exposed to source languages.</p>
2964
2965</div>
2966
2967<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2968<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2969<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2970</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2971
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2972<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2973<pre>
2974%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2975@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2976</pre>
2977<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor functions and associated priorities. The functions referenced by this array will be called in ascending order of priority (i.e. lowest first) when the module is loaded. The order of functions with the same priority is not defined.
2978</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2979
2980</div>
2981
2982<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2983<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2984<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2985</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2986
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2987<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2988<pre>
2989%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2990@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2991</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2992
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2993<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions and associated priorities. The functions referenced by this array will be called in descending order of priority (i.e. highest first) when the module is loaded. The order of functions with the same priority is not defined.
2994</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2995
2996</div>
2997
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2998</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2999
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]3000<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3001<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3002<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3003
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3004<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3005
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3006<p>The LLVM instruction set consists of several different classifications of
3007 instructions: <a href="#terminators">terminator
3008 instructions</a>, <a href="#binaryops">binary instructions</a>,
3009 <a href="#bitwiseops">bitwise binary instructions</a>,
3010 <a href="#memoryops">memory instructions</a>, and
3011 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3012
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3013<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3014<h3>
3015 <a name="terminators">Terminator Instructions</a>
3016</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3017
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3018<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3019
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3020<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3021 in a program ends with a "Terminator" instruction, which indicates which
3022 block should be executed after the current block is finished. These
3023 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3024 control flow, not values (the one exception being the
3025 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3026
Bill Wendling6c923bb2011-07-27 20:18:04 +0000[diff] [blame]3027<p>There are eight different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3028 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
3029 '<a href="#i_br"><tt>br</tt></a>' instruction, the
3030 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]3031 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3032 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
Bill Wendling6c923bb2011-07-27 20:18:04 +0000[diff] [blame]3033 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, the
3034 '<a href="#i_resume"><tt>resume</tt></a>' instruction, and the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3035 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3036
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3037<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3038<h4>
3039 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3040</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3041
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3042<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3043
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3044<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3045<pre>
3046 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]3047 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3048</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3049
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3050<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3051<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3052 a value) from a function back to the caller.</p>
3053
3054<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3055 value and then causes control flow, and one that just causes control flow to
3056 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3057
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3058<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3059<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3060 return value. The type of the return value must be a
3061 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3062
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3063<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3064 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3065 value or a return value with a type that does not match its type, or if it
3066 has a void return type and contains a '<tt>ret</tt>' instruction with a
3067 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3068
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3069<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3070<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3071 the calling function's context. If the caller is a
3072 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3073 instruction after the call. If the caller was an
3074 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3075 the beginning of the "normal" destination block. If the instruction returns
3076 a value, that value shall set the call or invoke instruction's return
3077 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3078
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3079<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3080<pre>
3081 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3082 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]3083 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]3084</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3085
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3086</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3087<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3088<h4>
3089 <a name="i_br">'<tt>br</tt>' Instruction</a>
3090</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3091
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3092<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3093
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3094<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3095<pre>
Bill Wendling16b86742011-07-26 10:41:15 +0000[diff] [blame]3096 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3097 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3098</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3099
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3100<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3101<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3102 different basic block in the current function. There are two forms of this
3103 instruction, corresponding to a conditional branch and an unconditional
3104 branch.</p>
3105
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3106<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3107<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3108 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3109 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3110 target.</p>
3111
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3112<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3113<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3114 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3115 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3116 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3117
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3118<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3119<pre>
3120Test:
3121 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3122 br i1 %cond, label %IfEqual, label %IfUnequal
3123IfEqual:
3124 <a href="#i_ret">ret</a> i32 1
3125IfUnequal:
3126 <a href="#i_ret">ret</a> i32 0
3127</pre>
3128
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3129</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3130
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3131<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3132<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3133 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3134</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3135
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3136<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3137
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3138<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3139<pre>
3140 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3141</pre>
3142
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3143<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3144<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]3145 several different places. It is a generalization of the '<tt>br</tt>'
3146 instruction, allowing a branch to occur to one of many possible
3147 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3148
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3149<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3150<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3151 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3152 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3153 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3154
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3155<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3156<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3157 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3158 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3159 transferred to the corresponding destination; otherwise, control flow is
3160 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3161
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3162<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3163<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3164 <tt>switch</tt> instruction, this instruction may be code generated in
3165 different ways. For example, it could be generated as a series of chained
3166 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3167
3168<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3169<pre>
3170 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3171 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3172 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3173
3174 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3175 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3176
3177 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3178 switch i32 %val, label %otherwise [ i32 0, label %onzero
3179 i32 1, label %onone
3180 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3181</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3182
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3183</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3184
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3185
3186<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3187<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3188 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3189</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3190
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3191<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3192
3193<h5>Syntax:</h5>
3194<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3195 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]3196</pre>
3197
3198<h5>Overview:</h5>
3199
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3200<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3201 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3202 "<tt>address</tt>". Address must be derived from a <a
3203 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3204
3205<h5>Arguments:</h5>
3206
3207<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3208 rest of the arguments indicate the full set of possible destinations that the
3209 address may point to. Blocks are allowed to occur multiple times in the
3210 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3211
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3212<p>This destination list is required so that dataflow analysis has an accurate
3213 understanding of the CFG.</p>
3214
3215<h5>Semantics:</h5>
3216
3217<p>Control transfers to the block specified in the address argument. All
3218 possible destination blocks must be listed in the label list, otherwise this
3219 instruction has undefined behavior. This implies that jumps to labels
3220 defined in other functions have undefined behavior as well.</p>
3221
3222<h5>Implementation:</h5>
3223
3224<p>This is typically implemented with a jump through a register.</p>
3225
3226<h5>Example:</h5>
3227<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3228 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3229</pre>
3230
3231</div>
3232
3233
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3234<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3235<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3236 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3237</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3238
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3239<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3240
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3241<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3242<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3243 &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]3244 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3245</pre>
3246
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3247<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3248<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3249 function, with the possibility of control flow transfer to either the
3250 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3251 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3252 control flow will return to the "normal" label. If the callee (or any
3253 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3254 instruction, control is interrupted and continued at the dynamically nearest
3255 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3256
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3257<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3258<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3259
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3260<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3261 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3262 convention</a> the call should use. If none is specified, the call
3263 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3264
3265 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3266 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3267 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3268
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3269 <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]3270 function value being invoked. In most cases, this is a direct function
3271 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3272 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3273
3274 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3275 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3276
3277 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3278 signature argument types and parameter attributes. All arguments must be
3279 of <a href="#t_firstclass">first class</a> type. If the function
3280 signature indicates the function accepts a variable number of arguments,
3281 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3282
3283 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3284 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3285
3286 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3287 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3288
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3289 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3290 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3291 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3292</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3293
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3294<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3295<p>This instruction is designed to operate as a standard
3296 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3297 primary difference is that it establishes an association with a label, which
3298 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3299
3300<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3301 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3302 exception. Additionally, this is important for implementation of
3303 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3304
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3305<p>For the purposes of the SSA form, the definition of the value returned by the
3306 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3307 block to the "normal" label. If the callee unwinds then no return value is
3308 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3309
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3310<p>Note that the code generator does not yet completely support unwind, and
3311that the invoke/unwind semantics are likely to change in future versions.</p>
3312
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3313<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3314<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3315 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3316 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3317 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3318 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3319</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3320
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3321</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3322
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3323<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3324
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3325<h4>
3326 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3327</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3328
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3329<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3330
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3331<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3332<pre>
3333 unwind
3334</pre>
3335
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3336<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3337<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3338 at the first callee in the dynamic call stack which used
3339 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3340 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3341
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3342<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3343<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3344 immediately halt. The dynamic call stack is then searched for the
3345 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3346 Once found, execution continues at the "exceptional" destination block
3347 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3348 instruction in the dynamic call chain, undefined behavior results.</p>
3349
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3350<p>Note that the code generator does not yet completely support unwind, and
3351that the invoke/unwind semantics are likely to change in future versions.</p>
3352
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3353</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3354
3355<!-- _______________________________________________________________________ -->
3356
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3357<h4>
Bill Wendling6c923bb2011-07-27 20:18:04 +0000[diff] [blame]3358 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3359</h4>
3360
3361<div>
3362
3363<h5>Syntax:</h5>
3364<pre>
3365 resume &lt;type&gt; &lt;value&gt;
3366</pre>
3367
3368<h5>Overview:</h5>
3369<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3370 successors. Its operand must have the same type as the result of any
3371 '<tt>landingpad</tt>' instruction in the same function.</p>
3372
3373<h5>Semantics:</h5>
3374<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3375 (in-flight) exception.</p>
3376
3377<h5>Example:</h5>
3378<pre>
3379 resume { i8*, i32 } %exn
3380</pre>
3381
3382</div>
3383
3384<!-- _______________________________________________________________________ -->
3385
3386<h4>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3387 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3388</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3389
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3390<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3391
3392<h5>Syntax:</h5>
3393<pre>
3394 unreachable
3395</pre>
3396
3397<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3398<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3399 instruction is used to inform the optimizer that a particular portion of the
3400 code is not reachable. This can be used to indicate that the code after a
3401 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3402
3403<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3404<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3405
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3406</div>
3407
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3408</div>
3409
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3410<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3411<h3>
3412 <a name="binaryops">Binary Operations</a>
3413</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3414
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3415<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3416
3417<p>Binary operators are used to do most of the computation in a program. They
3418 require two operands of the same type, execute an operation on them, and
3419 produce a single value. The operands might represent multiple data, as is
3420 the case with the <a href="#t_vector">vector</a> data type. The result value
3421 has the same type as its operands.</p>
3422
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3423<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3424
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3425<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3426<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3427 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3428</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3429
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3430<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3431
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3432<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3433<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3434 &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]3435 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3436 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3437 &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]3438</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3439
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3440<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3441<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3442
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3443<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3444<p>The two arguments to the '<tt>add</tt>' instruction must
3445 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3446 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3447
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3448<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3449<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3450
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3451<p>If the sum has unsigned overflow, the result returned is the mathematical
3452 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]3453
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3454<p>Because LLVM integers use a two's complement representation, this instruction
3455 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3456
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3457<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3458 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3459 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3460 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3461 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3462
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3463<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3464<pre>
3465 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3466</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3467
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3468</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3469
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3470<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3471<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3472 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3473</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3474
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3475<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3476
3477<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3478<pre>
3479 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3480</pre>
3481
3482<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3483<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3484
3485<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3486<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3487 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3488 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3489
3490<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3491<p>The value produced is the floating point sum of the two operands.</p>
3492
3493<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3494<pre>
3495 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3496</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3497
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3498</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3499
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3500<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3501<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3502 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3503</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3504
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3505<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3506
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3507<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3508<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3509 &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]3510 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3511 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3512 &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]3513</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3514
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3515<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3516<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3517 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3518
3519<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3520 '<tt>neg</tt>' instruction present in most other intermediate
3521 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3522
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3523<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3524<p>The two arguments to the '<tt>sub</tt>' instruction must
3525 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3526 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3527
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3528<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3529<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3530
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3531<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3532 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3533 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3534
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3535<p>Because LLVM integers use a two's complement representation, this instruction
3536 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3537
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3538<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3539 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3540 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3541 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3542 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3543
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3544<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3545<pre>
3546 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3547 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3548</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3549
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3550</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3551
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3552<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3553<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3554 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3555</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3556
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3557<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3558
3559<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3560<pre>
3561 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3562</pre>
3563
3564<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3565<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3566 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3567
3568<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3569 '<tt>fneg</tt>' instruction present in most other intermediate
3570 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3571
3572<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3573<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3574 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3575 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3576
3577<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3578<p>The value produced is the floating point difference of the two operands.</p>
3579
3580<h5>Example:</h5>
3581<pre>
3582 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3583 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3584</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3585
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3586</div>
3587
3588<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3589<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3590 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3591</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3592
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3593<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3594
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3595<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3596<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3597 &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]3598 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3599 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3600 &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]3601</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3602
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3603<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3604<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3605
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3606<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3607<p>The two arguments to the '<tt>mul</tt>' instruction must
3608 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3609 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3610
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3611<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3612<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3613
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3614<p>If the result of the multiplication has unsigned overflow, the result
3615 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3616 width of the result.</p>
3617
3618<p>Because LLVM integers use a two's complement representation, and the result
3619 is the same width as the operands, this instruction returns the correct
3620 result for both signed and unsigned integers. If a full product
3621 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3622 be sign-extended or zero-extended as appropriate to the width of the full
3623 product.</p>
3624
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3625<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3626 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3627 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3628 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3629 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3630
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3631<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3632<pre>
3633 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3634</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3635
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3636</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3637
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3638<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3639<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3640 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3641</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3642
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3643<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3644
3645<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3646<pre>
3647 &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]3648</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3649
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3650<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3651<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3652
3653<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3654<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3655 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3656 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3657
3658<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3659<p>The value produced is the floating point product of the two operands.</p>
3660
3661<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3662<pre>
3663 &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]3664</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3665
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3666</div>
3667
3668<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3669<h4>
3670 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3671</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3672
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3673<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3674
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3675<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3676<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3677 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3678 &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]3679</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3680
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3681<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3682<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3683
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3684<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3685<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3686 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3687 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3688
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3689<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3690<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3691
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3692<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3693 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3694
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3695<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3696
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3697<p>If the <tt>exact</tt> keyword is present, the result value of the
3698 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3699 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3700
3701
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3702<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3703<pre>
3704 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3705</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3706
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3707</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3708
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3709<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3710<h4>
3711 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3712</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3713
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3714<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3715
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3716<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3717<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3718 &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]3719 &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]3720</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3721
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3722<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3723<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3724
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3725<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3726<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3727 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3728 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3729
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3730<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3731<p>The value produced is the signed integer quotient of the two operands rounded
3732 towards zero.</p>
3733
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3734<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3735 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3736
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3737<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3738 undefined behavior; this is a rare case, but can occur, for example, by doing
3739 a 32-bit division of -2147483648 by -1.</p>
3740
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3741<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3742 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
Dan Gohmane501ff72010-07-11 00:08:34 +0000[diff] [blame]3743 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3744
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3745<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3746<pre>
3747 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3748</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3749
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3750</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3751
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3752<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3753<h4>
3754 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3755</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3756
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3757<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3758
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3759<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3760<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3761 &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]3762</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3763
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3764<h5>Overview:</h5>
3765<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3766
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3767<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3768<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3769 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3770 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3771
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3772<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3773<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3774
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3775<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3776<pre>
3777 &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]3778</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3779
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3780</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3781
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3782<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3783<h4>
3784 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3785</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3786
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3787<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3788
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3789<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3790<pre>
3791 &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]3792</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3793
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3794<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3795<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3796 division of its two arguments.</p>
3797
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3798<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3799<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3800 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3801 values. Both arguments must have identical types.</p>
3802
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3803<h5>Semantics:</h5>
3804<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3805 This instruction always performs an unsigned division to get the
3806 remainder.</p>
3807
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3808<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3809 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3810
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3811<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3812
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3813<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3814<pre>
3815 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3816</pre>
3817
3818</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3819
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3820<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3821<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3822 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3823</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3824
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3825<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3826
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3827<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3828<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3829 &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]3830</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3831
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3832<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3833<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3834 division of its two operands. This instruction can also take
3835 <a href="#t_vector">vector</a> versions of the values in which case the
3836 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3837
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3838<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3839<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3840 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3841 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3842
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3843<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3844<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3845 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3846 <i>modulo</i> operator (where the result is either zero or has the same sign
3847 as the divisor, <tt>op2</tt>) of a value.
3848 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3849 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3850 Math Forum</a>. For a table of how this is implemented in various languages,
3851 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3852 Wikipedia: modulo operation</a>.</p>
3853
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3854<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3855 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3856
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3857<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3858 Overflow also leads to undefined behavior; this is a rare case, but can
3859 occur, for example, by taking the remainder of a 32-bit division of
3860 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3861 lets srem be implemented using instructions that return both the result of
3862 the division and the remainder.)</p>
3863
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3864<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3865<pre>
3866 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3867</pre>
3868
3869</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3870
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3871<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3872<h4>
3873 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3874</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3875
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3876<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3877
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3878<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3879<pre>
3880 &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]3881</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3882
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3883<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3884<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3885 its two operands.</p>
3886
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3887<h5>Arguments:</h5>
3888<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3889 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3890 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3891
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3892<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3893<p>This instruction returns the <i>remainder</i> of a division. The remainder
3894 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3895
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3896<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3897<pre>
3898 &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]3899</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3900
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3901</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3902
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3903</div>
3904
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3905<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3906<h3>
3907 <a name="bitwiseops">Bitwise Binary Operations</a>
3908</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3909
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3910<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3911
3912<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3913 program. They are generally very efficient instructions and can commonly be
3914 strength reduced from other instructions. They require two operands of the
3915 same type, execute an operation on them, and produce a single value. The
3916 resulting value is the same type as its operands.</p>
3917
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3918<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3919<h4>
3920 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3921</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3922
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3923<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3924
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3925<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3926<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3927 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3928 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3929 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3930 &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]3931</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3932
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3933<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3934<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3935 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3936
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3937<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3938<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3939 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3940 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3941
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3942<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3943<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3944 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3945 is (statically or dynamically) negative or equal to or larger than the number
3946 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3947 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3948 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3949
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3950<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3951 <a href="#trapvalues">trap value</a> if it shifts out any non-zero bits. If
Chris Lattnerf10dfdc2011-02-09 16:44:44 +0000[diff] [blame]3952 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3953 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3954 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3955 they would if the shift were expressed as a mul instruction with the same
3956 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3957
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3958<h5>Example:</h5>
3959<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3960 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3961 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3962 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3963 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3964 &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]3965</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3966
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3967</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3968
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3969<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3970<h4>
3971 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3972</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3973
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3974<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3975
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3976<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3977<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3978 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3979 &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]3980</pre>
3981
3982<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3983<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3984 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3985
3986<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3987<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3988 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3989 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3990
3991<h5>Semantics:</h5>
3992<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3993 significant bits of the result will be filled with zero bits after the shift.
3994 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3995 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3996 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3997 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3998
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3999<p>If the <tt>exact</tt> keyword is present, the result value of the
4000 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4001 shifted out are non-zero.</p>
4002
4003
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4004<h5>Example:</h5>
4005<pre>
4006 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4007 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4008 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4009 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4010 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4011 &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]4012</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4013
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4014</div>
4015
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]4016<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4017<h4>
4018 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4019</h4>
4020
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4021<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4022
4023<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4024<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4025 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4026 &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]4027</pre>
4028
4029<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4030<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4031 operand shifted to the right a specified number of bits with sign
4032 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4033
4034<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4035<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4036 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4037 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4038
4039<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4040<p>This instruction always performs an arithmetic shift right operation, The
4041 most significant bits of the result will be filled with the sign bit
4042 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4043 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4044 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4045 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4046
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4047<p>If the <tt>exact</tt> keyword is present, the result value of the
4048 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4049 shifted out are non-zero.</p>
4050
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4051<h5>Example:</h5>
4052<pre>
4053 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4054 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4055 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4056 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4057 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4058 &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]4059</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4060
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4061</div>
4062
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4063<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4064<h4>
4065 <a name="i_and">'<tt>and</tt>' Instruction</a>
4066</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4067
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4068<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4069
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4070<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4071<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4072 &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]4073</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4074
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4075<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4076<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4077 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4078
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4079<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4080<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4081 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4082 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4083
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4084<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4085<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4086
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4087<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4088 <tbody>
4089 <tr>
4090 <td>In0</td>
4091 <td>In1</td>
4092 <td>Out</td>
4093 </tr>
4094 <tr>
4095 <td>0</td>
4096 <td>0</td>
4097 <td>0</td>
4098 </tr>
4099 <tr>
4100 <td>0</td>
4101 <td>1</td>
4102 <td>0</td>
4103 </tr>
4104 <tr>
4105 <td>1</td>
4106 <td>0</td>
4107 <td>0</td>
4108 </tr>
4109 <tr>
4110 <td>1</td>
4111 <td>1</td>
4112 <td>1</td>
4113 </tr>
4114 </tbody>
4115</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4116
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4117<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4118<pre>
4119 &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]4120 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4121 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4122</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4123</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4124<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4125<h4>
4126 <a name="i_or">'<tt>or</tt>' Instruction</a>
4127</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4128
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4129<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4130
4131<h5>Syntax:</h5>
4132<pre>
4133 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4134</pre>
4135
4136<h5>Overview:</h5>
4137<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4138 two operands.</p>
4139
4140<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4141<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4142 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4143 values. Both arguments must have identical types.</p>
4144
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4145<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4146<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4147
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4148<table border="1" cellspacing="0" cellpadding="4">
4149 <tbody>
4150 <tr>
4151 <td>In0</td>
4152 <td>In1</td>
4153 <td>Out</td>
4154 </tr>
4155 <tr>
4156 <td>0</td>
4157 <td>0</td>
4158 <td>0</td>
4159 </tr>
4160 <tr>
4161 <td>0</td>
4162 <td>1</td>
4163 <td>1</td>
4164 </tr>
4165 <tr>
4166 <td>1</td>
4167 <td>0</td>
4168 <td>1</td>
4169 </tr>
4170 <tr>
4171 <td>1</td>
4172 <td>1</td>
4173 <td>1</td>
4174 </tr>
4175 </tbody>
4176</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4177
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4178<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4179<pre>
4180 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4181 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4182 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4183</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4184
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4185</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4186
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4187<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4188<h4>
4189 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4190</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4191
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4192<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4193
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4194<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4195<pre>
4196 &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]4197</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4198
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4199<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4200<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4201 its two operands. The <tt>xor</tt> is used to implement the "one's
4202 complement" operation, which is the "~" operator in C.</p>
4203
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4204<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4205<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4206 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4207 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4208
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4209<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4210<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4211
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4212<table border="1" cellspacing="0" cellpadding="4">
4213 <tbody>
4214 <tr>
4215 <td>In0</td>
4216 <td>In1</td>
4217 <td>Out</td>
4218 </tr>
4219 <tr>
4220 <td>0</td>
4221 <td>0</td>
4222 <td>0</td>
4223 </tr>
4224 <tr>
4225 <td>0</td>
4226 <td>1</td>
4227 <td>1</td>
4228 </tr>
4229 <tr>
4230 <td>1</td>
4231 <td>0</td>
4232 <td>1</td>
4233 </tr>
4234 <tr>
4235 <td>1</td>
4236 <td>1</td>
4237 <td>0</td>
4238 </tr>
4239 </tbody>
4240</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4241
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4242<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4243<pre>
4244 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4245 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4246 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4247 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4248</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4249
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4250</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4251
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4252</div>
4253
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4254<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4255<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4256 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4257</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4258
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4259<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4260
4261<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4262 target-independent manner. These instructions cover the element-access and
4263 vector-specific operations needed to process vectors effectively. While LLVM
4264 does directly support these vector operations, many sophisticated algorithms
4265 will want to use target-specific intrinsics to take full advantage of a
4266 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4267
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4268<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4269<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4270 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4271</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4272
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4273<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4274
4275<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4276<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4277 &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]4278</pre>
4279
4280<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4281<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4282 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4283
4284
4285<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4286<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4287 of <a href="#t_vector">vector</a> type. The second operand is an index
4288 indicating the position from which to extract the element. The index may be
4289 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4290
4291<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4292<p>The result is a scalar of the same type as the element type of
4293 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4294 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4295 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4296
4297<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4298<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4299 &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]4300</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4301
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4302</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4303
4304<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4305<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4306 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4307</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4308
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4309<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4310
4311<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4312<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4313 &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]4314</pre>
4315
4316<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4317<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4318 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4319
4320<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4321<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4322 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4323 whose type must equal the element type of the first operand. The third
4324 operand is an index indicating the position at which to insert the value.
4325 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4326
4327<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4328<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4329 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4330 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4331 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4332
4333<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4334<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4335 &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]4336</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4337
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4338</div>
4339
4340<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4341<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4342 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4343</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4344
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4345<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4346
4347<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4348<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4349 &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]4350</pre>
4351
4352<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4353<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4354 from two input vectors, returning a vector with the same element type as the
4355 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4356
4357<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4358<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4359 with types that match each other. The third argument is a shuffle mask whose
4360 element type is always 'i32'. The result of the instruction is a vector
4361 whose length is the same as the shuffle mask and whose element type is the
4362 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4363
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4364<p>The shuffle mask operand is required to be a constant vector with either
4365 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4366
4367<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4368<p>The elements of the two input vectors are numbered from left to right across
4369 both of the vectors. The shuffle mask operand specifies, for each element of
4370 the result vector, which element of the two input vectors the result element
4371 gets. The element selector may be undef (meaning "don't care") and the
4372 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4373
4374<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4375<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4376 &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]4377 &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]4378 &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]4379 &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]4380 &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]4381 &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]4382 &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]4383 &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]4384</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4385
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4386</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4387
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4388</div>
4389
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4390<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4391<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4392 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4393</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4394
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4395<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4396
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4397<p>LLVM supports several instructions for working with
4398 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4399
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4400<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4401<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4402 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4403</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4404
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4405<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4406
4407<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4408<pre>
4409 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4410</pre>
4411
4412<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4413<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4414 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4415
4416<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4417<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4418 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4419 <a href="#t_array">array</a> type. The operands are constant indices to
4420 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4421 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4422 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4423 <ul>
4424 <li>Since the value being indexed is not a pointer, the first index is
4425 omitted and assumed to be zero.</li>
4426 <li>At least one index must be specified.</li>
4427 <li>Not only struct indices but also array indices must be in
4428 bounds.</li>
4429 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4430
4431<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4432<p>The result is the value at the position in the aggregate specified by the
4433 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4434
4435<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4436<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4437 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4438</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4439
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4440</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4441
4442<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4443<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4444 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4445</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4446
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4447<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4448
4449<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4450<pre>
Bill Wendlingf6a91cf2011-07-26 20:42:28 +0000[diff] [blame]4451 &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]4452</pre>
4453
4454<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4455<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4456 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4457
4458<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4459<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4460 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4461 <a href="#t_array">array</a> type. The second operand is a first-class
4462 value to insert. The following operands are constant indices indicating
4463 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]4464 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4465 value to insert must have the same type as the value identified by the
4466 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4467
4468<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4469<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4470 that of <tt>val</tt> except that the value at the position specified by the
4471 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4472
4473<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4474<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4475 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4476 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4477 %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]4478</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4479
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4480</div>
4481
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4482</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4483
4484<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4485<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4486 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4487</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4488
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4489<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4490
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4491<p>A key design point of an SSA-based representation is how it represents
4492 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4493 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4494 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4495
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4496<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4497<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4498 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4499</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4500
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4501<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4502
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4503<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4504<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4505 &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]4506</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4507
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4508<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4509<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4510 currently executing function, to be automatically released when this function
4511 returns to its caller. The object is always allocated in the generic address
4512 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4513
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4514<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4515<p>The '<tt>alloca</tt>' instruction
4516 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4517 runtime stack, returning a pointer of the appropriate type to the program.
4518 If "NumElements" is specified, it is the number of elements allocated,
4519 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4520 specified, the value result of the allocation is guaranteed to be aligned to
4521 at least that boundary. If not specified, or if zero, the target can choose
4522 to align the allocation on any convenient boundary compatible with the
4523 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4524
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4525<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4526
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4527<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4528<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4529 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4530 memory is automatically released when the function returns. The
4531 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4532 variables that must have an address available. When the function returns
4533 (either with the <tt><a href="#i_ret">ret</a></tt>
4534 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4535 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4536
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4537<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4538<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4539 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4540 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4541 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4542 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4543</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4544
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4545</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4546
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4547<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4548<h4>
4549 <a name="i_load">'<tt>load</tt>' Instruction</a>
4550</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4551
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4552<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4553
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4554<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4555<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4556 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4557 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4558 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4559</pre>
4560
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4561<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4562<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4563
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4564<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4565<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4566 from which to load. The pointer must point to
4567 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4568 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4569 number or order of execution of this <tt>load</tt> with other <a
4570 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4571
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4572<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4573 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]4574 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4575 alignment for the target. It is the responsibility of the code emitter to
4576 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4577 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4578 produce less efficient code. An alignment of 1 is always safe.</p>
4579
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4580<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4581 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4582 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4583 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4584 and code generator that this load is not expected to be reused in the cache.
4585 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4586 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4587
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4588<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4589<p>The location of memory pointed to is loaded. If the value being loaded is of
4590 scalar type then the number of bytes read does not exceed the minimum number
4591 of bytes needed to hold all bits of the type. For example, loading an
4592 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4593 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4594 is undefined if the value was not originally written using a store of the
4595 same type.</p>
4596
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4597<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4598<pre>
4599 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4600 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4601 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4602</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4603
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4604</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4605
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4606<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4607<h4>
4608 <a name="i_store">'<tt>store</tt>' Instruction</a>
4609</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4610
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4611<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4612
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4613<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4614<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4615 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4616 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4617</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4618
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4619<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4620<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4621
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4622<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4623<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4624 and an address at which to store it. The type of the
4625 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4626 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4627 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4628 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4629 order of execution of this <tt>store</tt> with other <a
4630 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4631
4632<p>The optional constant "align" argument specifies the alignment of the
4633 operation (that is, the alignment of the memory address). A value of 0 or an
4634 omitted "align" argument means that the operation has the preferential
4635 alignment for the target. It is the responsibility of the code emitter to
4636 ensure that the alignment information is correct. Overestimating the
4637 alignment results in an undefined behavior. Underestimating the alignment may
4638 produce less efficient code. An alignment of 1 is always safe.</p>
4639
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4640<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4641 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4642 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4643 instruction tells the optimizer and code generator that this load is
4644 not expected to be reused in the cache. The code generator may
4645 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4646 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4647
4648
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4649<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4650<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4651 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4652 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4653 does not exceed the minimum number of bytes needed to hold all bits of the
4654 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4655 writing a value of a type like <tt>i20</tt> with a size that is not an
4656 integral number of bytes, it is unspecified what happens to the extra bits
4657 that do not belong to the type, but they will typically be overwritten.</p>
4658
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4659<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4660<pre>
4661 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4662 store i32 3, i32* %ptr <i>; yields {void}</i>
4663 %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]4664</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4665
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4666</div>
4667
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4668<!-- _______________________________________________________________________ -->
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]4669<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4670Instruction</a> </div>
4671
4672<div class="doc_text">
4673
4674<h5>Syntax:</h5>
4675<pre>
4676 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4677</pre>
4678
4679<h5>Overview:</h5>
4680<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4681between operations.</p>
4682
4683<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4684href="#ordering">ordering</a> argument which defines what
4685<i>synchronizes-with</i> edges they add. They can only be given
4686<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4687<code>seq_cst</code> orderings.</p>
4688
4689<h5>Semantics:</h5>
4690<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4691semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4692<code>acquire</code> ordering semantics if and only if there exist atomic
4693operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4694<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4695<var>X</var> modifies <var>M</var> (either directly or through some side effect
4696of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4697<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4698<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4699than an explicit <code>fence</code>, one (but not both) of the atomic operations
4700<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4701<code>acquire</code> (resp.) ordering constraint and still
4702<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4703<i>happens-before</i> edge.</p>
4704
4705<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4706having both <code>acquire</code> and <code>release</code> semantics specified
4707above, participates in the global program order of other <code>seq_cst</code>
4708operations and/or fences.</p>
4709
4710<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4711specifies that the fence only synchronizes with other fences in the same
4712thread. (This is useful for interacting with signal handlers.)</p>
4713
4714<p>FIXME: This instruction is a work in progress; until it is finished, use
4715 llvm.memory.barrier.
4716
4717<h5>Example:</h5>
4718<pre>
4719 fence acquire <i>; yields {void}</i>
4720 fence singlethread seq_cst <i>; yields {void}</i>
4721</pre>
4722
4723</div>
4724
4725<!-- _______________________________________________________________________ -->
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame^]4726<div class="doc_subsubsection"> <a name="i_cmpxchg">'<tt>cmpxchg</tt>'
4727Instruction</a> </div>
4728
4729<div class="doc_text">
4730
4731<h5>Syntax:</h5>
4732<pre>
4733 [volatile] cmpxchg &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>
4734</pre>
4735
4736<h5>Overview:</h5>
4737<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4738It loads a value in memory and compares it to a given value. If they are
4739equal, it stores a new value into the memory.</p>
4740
4741<h5>Arguments:</h5>
4742<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4743address to operate on, a value to compare to the value currently be at that
4744address, and a new value to place at that address if the compared values are
4745equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4746bit width is a power of two greater than or equal to eight and less than
4747or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4748'<var>&lt;new&gt;</var>' must have the same type, and the type of
4749'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4750<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4751optimizer is not allowed to modify the number or order of execution
4752of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4753operations</a>.</p>
4754
4755<!-- FIXME: Extend allowed types. -->
4756
4757<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4758<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4759
4760<p>The optional "<code>singlethread</code>" argument declares that the
4761<code>cmpxchg</code> is only atomic with respect to code (usually signal
4762handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4763cmpxchg is atomic with respect to all other code in the system.</p>
4764
4765<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4766the size in memory of the operand.
4767
4768<h5>Semantics:</h5>
4769<p>The contents of memory at the location specified by the
4770'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4771'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4772'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4773is returned.
4774
4775<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4776purpose of identifying <a href="#release_sequence">release sequences</a>. A
4777failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4778parameter determined by dropping any <code>release</code> part of the
4779<code>cmpxchg</code>'s ordering.</p>
4780
4781<!--
4782FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4783optimization work on ARM.)
4784
4785FIXME: Is a weaker ordering constraint on failure helpful in practice?
4786-->
4787
4788<h5>Example:</h5>
4789<pre>
4790entry:
4791 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4792 <a href="#i_br">br</a> label %loop
4793
4794loop:
4795 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4796 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4797 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4798 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4799 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4800
4801done:
4802 ...
4803</pre>
4804
4805</div>
4806
4807<!-- _______________________________________________________________________ -->
4808<div class="doc_subsubsection"> <a name="i_atomicrmw">'<tt>atomicrmw</tt>'
4809Instruction</a> </div>
4810
4811<div class="doc_text">
4812
4813<h5>Syntax:</h5>
4814<pre>
4815 [volatile] atomicrmw &lt;operation&gt; &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;value&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
4816</pre>
4817
4818<h5>Overview:</h5>
4819<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4820
4821<h5>Arguments:</h5>
4822<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4823operation to apply, an address whose value to modify, an argument to the
4824operation. The operation must be one of the following keywords:</p>
4825<ul>
4826 <li>xchg</li>
4827 <li>add</li>
4828 <li>sub</li>
4829 <li>and</li>
4830 <li>nand</li>
4831 <li>or</li>
4832 <li>xor</li>
4833 <li>max</li>
4834 <li>min</li>
4835 <li>umax</li>
4836 <li>umin</li>
4837</ul>
4838
4839<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4840bit width is a power of two greater than or equal to eight and less than
4841or equal to a target-specific size limit. The type of the
4842'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4843If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4844optimizer is not allowed to modify the number or order of execution of this
4845<code>atomicrmw</code> with other <a href="#volatile">volatile
4846 operations</a>.</p>
4847
4848<!-- FIXME: Extend allowed types. -->
4849
4850<h5>Semantics:</h5>
4851<p>The contents of memory at the location specified by the
4852'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4853back. The original value at the location is returned. The modification is
4854specified by the <var>operation</var> argument:</p>
4855
4856<ul>
4857 <li>xchg: <code>*ptr = val</code></li>
4858 <li>add: <code>*ptr = *ptr + val</code></li>
4859 <li>sub: <code>*ptr = *ptr - val</code></li>
4860 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4861 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4862 <li>or: <code>*ptr = *ptr | val</code></li>
4863 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4864 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4865 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4866 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4867 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4868</ul>
4869
4870<h5>Example:</h5>
4871<pre>
4872 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4873</pre>
4874
4875</div>
4876
4877<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4878<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4879 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4880</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4881
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4882<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4883
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4884<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4885<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4886 &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]4887 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4888</pre>
4889
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4890<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4891<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4892 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4893 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4894
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4895<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4896<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4897 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4898 elements of the aggregate object are indexed. The interpretation of each
4899 index is dependent on the type being indexed into. The first index always
4900 indexes the pointer value given as the first argument, the second index
4901 indexes a value of the type pointed to (not necessarily the value directly
4902 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4903 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4904 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4905 can never be pointers, since that would require loading the pointer before
4906 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4907
4908<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]4909 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4910 integer <b>constants</b> are allowed. When indexing into an array, pointer
4911 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4912 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4913
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4914<p>For example, let's consider a C code fragment and how it gets compiled to
4915 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4916
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4917<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4918struct RT {
4919 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4920 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4921 char C;
4922};
4923struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4924 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4925 double Y;
4926 struct RT Z;
4927};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4928
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4929int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4930 return &amp;s[1].Z.B[5][13];
4931}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4932</pre>
4933
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4934<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4935
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4936<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4937%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4938%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4939
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4940define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4941entry:
4942 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4943 ret i32* %reg
4944}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4945</pre>
4946
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4947<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4948<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4949 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4950 }</tt>' type, a structure. The second index indexes into the third element
4951 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4952 i8 }</tt>' type, another structure. The third index indexes into the second
4953 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4954 array. The two dimensions of the array are subscripted into, yielding an
4955 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4956 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4957
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4958<p>Note that it is perfectly legal to index partially through a structure,
4959 returning a pointer to an inner element. Because of this, the LLVM code for
4960 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4961
4962<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4963 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4964 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4965 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4966 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4967 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4968 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4969 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4970 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4971</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4972
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4973<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4974 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4975 base pointer is not an <i>in bounds</i> address of an allocated object,
4976 or if any of the addresses that would be formed by successive addition of
4977 the offsets implied by the indices to the base address with infinitely
4978 precise arithmetic are not an <i>in bounds</i> address of that allocated
4979 object. The <i>in bounds</i> addresses for an allocated object are all
4980 the addresses that point into the object, plus the address one byte past
4981 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4982
4983<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4984 the base address with silently-wrapping two's complement arithmetic, and
4985 the result value of the <tt>getelementptr</tt> may be outside the object
4986 pointed to by the base pointer. The result value may not necessarily be
4987 used to access memory though, even if it happens to point into allocated
4988 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4989 section for more information.</p>
4990
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4991<p>The getelementptr instruction is often confusing. For some more insight into
4992 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4993
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4994<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4995<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4996 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4997 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4998 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4999 %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]5000 <i>; yields i8*:eptr</i>
5001 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]5002 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]5003 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5004</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5005
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5006</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]5007
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5008</div>
5009
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5010<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5011<h3>
5012 <a name="convertops">Conversion Operations</a>
5013</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5014
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5015<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5016
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5017<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5018 which all take a single operand and a type. They perform various bit
5019 conversions on the operand.</p>
5020
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5021<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5022<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5023 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5024</h4>
5025
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5026<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5027
5028<h5>Syntax:</h5>
5029<pre>
5030 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5031</pre>
5032
5033<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5034<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5035 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5036
5037<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5038<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5039 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5040 of the same number of integers.
5041 The bit size of the <tt>value</tt> must be larger than
5042 the bit size of the destination type, <tt>ty2</tt>.
5043 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5044
5045<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5046<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5047 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5048 source size must be larger than the destination size, <tt>trunc</tt> cannot
5049 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5050
5051<h5>Example:</h5>
5052<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5053 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5054 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5055 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5056 %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]5057</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5058
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5059</div>
5060
5061<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5062<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5063 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5064</h4>
5065
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5066<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5067
5068<h5>Syntax:</h5>
5069<pre>
5070 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5071</pre>
5072
5073<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5074<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5075 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5076
5077
5078<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5079<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5080 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5081 of the same number of integers.
5082 The bit size of the <tt>value</tt> must be smaller than
5083 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5084 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5085
5086<h5>Semantics:</h5>
5087<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]5088 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5089
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]5090<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]5091
5092<h5>Example:</h5>
5093<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5094 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5095 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5096 %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]5097</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5098
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5099</div>
5100
5101<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5102<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5103 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5104</h4>
5105
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5106<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5107
5108<h5>Syntax:</h5>
5109<pre>
5110 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5111</pre>
5112
5113<h5>Overview:</h5>
5114<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5115
5116<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5117<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5118 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5119 of the same number of integers.
5120 The bit size of the <tt>value</tt> must be smaller than
5121 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5122 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5123
5124<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5125<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5126 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5127 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5128
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5129<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]5130
5131<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5132<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5133 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5134 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5135 %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]5136</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5137
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5138</div>
5139
5140<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5141<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5142 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5143</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5144
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5145<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5146
5147<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5148<pre>
5149 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5150</pre>
5151
5152<h5>Overview:</h5>
5153<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5154 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5155
5156<h5>Arguments:</h5>
5157<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5158 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5159 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]5160 <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]5161 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5162
5163<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5164<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5165 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5166 <a href="#t_floating">floating point</a> type. If the value cannot fit
5167 within the destination type, <tt>ty2</tt>, then the results are
5168 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5169
5170<h5>Example:</h5>
5171<pre>
5172 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5173 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5174</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5175
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5176</div>
5177
5178<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5179<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5180 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5181</h4>
5182
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5183<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5184
5185<h5>Syntax:</h5>
5186<pre>
5187 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5188</pre>
5189
5190<h5>Overview:</h5>
5191<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]5192 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5193
5194<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5195<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5196 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5197 a <a href="#t_floating">floating point</a> type to cast it to. The source
5198 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5199
5200<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5201<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5202 <a href="#t_floating">floating point</a> type to a larger
5203 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5204 used to make a <i>no-op cast</i> because it always changes bits. Use
5205 <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]5206
5207<h5>Example:</h5>
5208<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]5209 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5210 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5211</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5212
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5213</div>
5214
5215<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5216<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]5217 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5218</h4>
5219
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5220<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5221
5222<h5>Syntax:</h5>
5223<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5224 &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]5225</pre>
5226
5227<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5228<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5229 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5230
5231<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5232<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5233 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5234 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5235 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5236 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5237
5238<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5239<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5240 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5241 towards zero) unsigned integer value. If the value cannot fit
5242 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5243
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5244<h5>Example:</h5>
5245<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5246 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5247 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5248 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5249</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5250
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5251</div>
5252
5253<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5254<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5255 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5256</h4>
5257
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5258<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5259
5260<h5>Syntax:</h5>
5261<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5262 &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]5263</pre>
5264
5265<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5266<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5267 <a href="#t_floating">floating point</a> <tt>value</tt> to
5268 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5269
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5270<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5271<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5272 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5273 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5274 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5275 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5276
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5277<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5278<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5279 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5280 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5281 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5282
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5283<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5284<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5285 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5286 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5287 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5288</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5289
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5290</div>
5291
5292<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5293<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5294 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5295</h4>
5296
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5297<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5298
5299<h5>Syntax:</h5>
5300<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5301 &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]5302</pre>
5303
5304<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5305<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5306 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5307
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5308<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5309<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]5310 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5311 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5312 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5313 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5314
5315<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5316<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5317 integer quantity and converts it to the corresponding floating point
5318 value. If the value cannot fit in the floating point value, the results are
5319 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5320
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5321<h5>Example:</h5>
5322<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5323 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5324 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5325</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5326
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5327</div>
5328
5329<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5330<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5331 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5332</h4>
5333
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5334<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5335
5336<h5>Syntax:</h5>
5337<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5338 &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]5339</pre>
5340
5341<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5342<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5343 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5344
5345<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5346<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]5347 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5348 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5349 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5350 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5351
5352<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5353<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5354 quantity and converts it to the corresponding floating point value. If the
5355 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5356
5357<h5>Example:</h5>
5358<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5359 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5360 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5361</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5362
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5363</div>
5364
5365<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5366<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5367 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5368</h4>
5369
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5370<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5371
5372<h5>Syntax:</h5>
5373<pre>
5374 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5375</pre>
5376
5377<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5378<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5379 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5380
5381<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5382<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5383 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5384 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5385
5386<h5>Semantics:</h5>
5387<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5388 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5389 truncating or zero extending that value to the size of the integer type. If
5390 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5391 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5392 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5393 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5394
5395<h5>Example:</h5>
5396<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5397 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5398 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5399</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5400
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5401</div>
5402
5403<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5404<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5405 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5406</h4>
5407
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5408<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5409
5410<h5>Syntax:</h5>
5411<pre>
5412 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5413</pre>
5414
5415<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5416<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5417 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5418
5419<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5420<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5421 value to cast, and a type to cast it to, which must be a
5422 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5423
5424<h5>Semantics:</h5>
5425<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5426 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5427 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5428 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5429 than the size of a pointer then a zero extension is done. If they are the
5430 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5431
5432<h5>Example:</h5>
5433<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5434 %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]5435 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5436 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5437</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5438
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5439</div>
5440
5441<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5442<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5443 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5444</h4>
5445
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5446<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5447
5448<h5>Syntax:</h5>
5449<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5450 &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]5451</pre>
5452
5453<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5454<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5455 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5456
5457<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5458<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5459 non-aggregate first class value, and a type to cast it to, which must also be
5460 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5461 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5462 identical. If the source type is a pointer, the destination type must also be
5463 a pointer. This instruction supports bitwise conversion of vectors to
5464 integers and to vectors of other types (as long as they have the same
5465 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5466
5467<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5468<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5469 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5470 this conversion. The conversion is done as if the <tt>value</tt> had been
5471 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5472 be converted to other pointer types with this instruction. To convert
5473 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5474 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5475
5476<h5>Example:</h5>
5477<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5478 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5479 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5480 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5481</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5482
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5483</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5484
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5485</div>
5486
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5487<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5488<h3>
5489 <a name="otherops">Other Operations</a>
5490</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5491
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5492<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5493
5494<p>The instructions in this category are the "miscellaneous" instructions, which
5495 defy better classification.</p>
5496
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5497<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5498<h4>
5499 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5500</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5501
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5502<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5503
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5504<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5505<pre>
5506 &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]5507</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5508
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5509<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5510<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5511 boolean values based on comparison of its two integer, integer vector, or
5512 pointer operands.</p>
5513
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5514<h5>Arguments:</h5>
5515<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5516 the condition code indicating the kind of comparison to perform. It is not a
5517 value, just a keyword. The possible condition code are:</p>
5518
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5519<ol>
5520 <li><tt>eq</tt>: equal</li>
5521 <li><tt>ne</tt>: not equal </li>
5522 <li><tt>ugt</tt>: unsigned greater than</li>
5523 <li><tt>uge</tt>: unsigned greater or equal</li>
5524 <li><tt>ult</tt>: unsigned less than</li>
5525 <li><tt>ule</tt>: unsigned less or equal</li>
5526 <li><tt>sgt</tt>: signed greater than</li>
5527 <li><tt>sge</tt>: signed greater or equal</li>
5528 <li><tt>slt</tt>: signed less than</li>
5529 <li><tt>sle</tt>: signed less or equal</li>
5530</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5531
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5532<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5533 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5534 typed. They must also be identical types.</p>
5535
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5536<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5537<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5538 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5539 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]5540 result, as follows:</p>
5541
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5542<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5543 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5544 <tt>false</tt> otherwise. No sign interpretation is necessary or
5545 performed.</li>
5546
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5547 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5548 <tt>false</tt> otherwise. No sign interpretation is necessary or
5549 performed.</li>
5550
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5551 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5552 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5553
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5554 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5555 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5556 to <tt>op2</tt>.</li>
5557
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5558 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5559 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5560
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5561 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5562 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5563
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5564 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5565 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5566
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5567 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5568 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5569 to <tt>op2</tt>.</li>
5570
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5571 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5572 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5573
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5574 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5575 <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]5576</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5577
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5578<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5579 values are compared as if they were integers.</p>
5580
5581<p>If the operands are integer vectors, then they are compared element by
5582 element. The result is an <tt>i1</tt> vector with the same number of elements
5583 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5584
5585<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5586<pre>
5587 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5588 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5589 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5590 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5591 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5592 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5593</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5594
5595<p>Note that the code generator does not yet support vector types with
5596 the <tt>icmp</tt> instruction.</p>
5597
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5598</div>
5599
5600<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5601<h4>
5602 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5603</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5604
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5605<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5606
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5607<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5608<pre>
5609 &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]5610</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5611
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5612<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5613<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5614 values based on comparison of its operands.</p>
5615
5616<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]5617(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5618
5619<p>If the operands are floating point vectors, then the result type is a vector
5620 of boolean with the same number of elements as the operands being
5621 compared.</p>
5622
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5623<h5>Arguments:</h5>
5624<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5625 the condition code indicating the kind of comparison to perform. It is not a
5626 value, just a keyword. The possible condition code are:</p>
5627
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5628<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5629 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5630 <li><tt>oeq</tt>: ordered and equal</li>
5631 <li><tt>ogt</tt>: ordered and greater than </li>
5632 <li><tt>oge</tt>: ordered and greater than or equal</li>
5633 <li><tt>olt</tt>: ordered and less than </li>
5634 <li><tt>ole</tt>: ordered and less than or equal</li>
5635 <li><tt>one</tt>: ordered and not equal</li>
5636 <li><tt>ord</tt>: ordered (no nans)</li>
5637 <li><tt>ueq</tt>: unordered or equal</li>
5638 <li><tt>ugt</tt>: unordered or greater than </li>
5639 <li><tt>uge</tt>: unordered or greater than or equal</li>
5640 <li><tt>ult</tt>: unordered or less than </li>
5641 <li><tt>ule</tt>: unordered or less than or equal</li>
5642 <li><tt>une</tt>: unordered or not equal</li>
5643 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5644 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5645</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5646
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5647<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5648 <i>unordered</i> means that either operand may be a QNAN.</p>
5649
5650<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5651 a <a href="#t_floating">floating point</a> type or
5652 a <a href="#t_vector">vector</a> of floating point type. They must have
5653 identical types.</p>
5654
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5655<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5656<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5657 according to the condition code given as <tt>cond</tt>. If the operands are
5658 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5659 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5660 follows:</p>
5661
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5662<ol>
5663 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5664
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5665 <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]5666 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5667
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5668 <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]5669 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5670
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5671 <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]5672 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5673
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5674 <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]5675 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5676
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5677 <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]5678 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5679
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5680 <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]5681 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5682
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5683 <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]5684
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5685 <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]5686 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5687
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5688 <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]5689 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5690
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5691 <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]5692 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5693
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5694 <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]5695 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5696
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5697 <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]5698 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5699
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5700 <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]5701 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5702
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5703 <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]5704
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5705 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5706</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5707
5708<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5709<pre>
5710 &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]5711 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5712 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5713 &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]5714</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5715
5716<p>Note that the code generator does not yet support vector types with
5717 the <tt>fcmp</tt> instruction.</p>
5718
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5719</div>
5720
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5721<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5722<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5723 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5724</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5725
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5726<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5727
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5728<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5729<pre>
5730 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5731</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5732
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5733<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5734<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5735 SSA graph representing the function.</p>
5736
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5737<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5738<p>The type of the incoming values is specified with the first type field. After
5739 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5740 one pair for each predecessor basic block of the current block. Only values
5741 of <a href="#t_firstclass">first class</a> type may be used as the value
5742 arguments to the PHI node. Only labels may be used as the label
5743 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5744
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5745<p>There must be no non-phi instructions between the start of a basic block and
5746 the PHI instructions: i.e. PHI instructions must be first in a basic
5747 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5748
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5749<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5750 occur on the edge from the corresponding predecessor block to the current
5751 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5752 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5753
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5754<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5755<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5756 specified by the pair corresponding to the predecessor basic block that
5757 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5758
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5759<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5760<pre>
5761Loop: ; Infinite loop that counts from 0 on up...
5762 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5763 %nextindvar = add i32 %indvar, 1
5764 br label %Loop
5765</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5766
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5767</div>
5768
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5769<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5770<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5771 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5772</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5773
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5774<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5775
5776<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5777<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5778 &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>
5779
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5780 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5781</pre>
5782
5783<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5784<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5785 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5786
5787
5788<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5789<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5790 values indicating the condition, and two values of the
5791 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5792 vectors and the condition is a scalar, then entire vectors are selected, not
5793 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5794
5795<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5796<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5797 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5798
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5799<p>If the condition is a vector of i1, then the value arguments must be vectors
5800 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5801
5802<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5803<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5804 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5805</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5806
5807<p>Note that the code generator does not yet support conditions
5808 with vector type.</p>
5809
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5810</div>
5811
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5812<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5813<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5814 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5815</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5816
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5817<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5818
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5819<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5820<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5821 &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]5822</pre>
5823
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5824<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5825<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5826
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5827<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5828<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5829
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5830<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5831 <li>The optional "tail" marker indicates that the callee function does not
5832 access any allocas or varargs in the caller. Note that calls may be
5833 marked "tail" even if they do not occur before
5834 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5835 present, the function call is eligible for tail call optimization,
5836 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5837 optimized into a jump</a>. The code generator may optimize calls marked
5838 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5839 sibling call optimization</a> when the caller and callee have
5840 matching signatures, or 2) forced tail call optimization when the
5841 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5842 <ul>
5843 <li>Caller and callee both have the calling
5844 convention <tt>fastcc</tt>.</li>
5845 <li>The call is in tail position (ret immediately follows call and ret
5846 uses value of call or is void).</li>
5847 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5848 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5849 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5850 constraints are met.</a></li>
5851 </ul>
5852 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5853
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5854 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5855 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5856 defaults to using C calling conventions. The calling convention of the
5857 call must match the calling convention of the target function, or else the
5858 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5859
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5860 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5861 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5862 '<tt>inreg</tt>' attributes are valid here.</li>
5863
5864 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5865 type of the return value. Functions that return no value are marked
5866 <tt><a href="#t_void">void</a></tt>.</li>
5867
5868 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5869 being invoked. The argument types must match the types implied by this
5870 signature. This type can be omitted if the function is not varargs and if
5871 the function type does not return a pointer to a function.</li>
5872
5873 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5874 be invoked. In most cases, this is a direct function invocation, but
5875 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5876 to function value.</li>
5877
5878 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5879 signature argument types and parameter attributes. All arguments must be
5880 of <a href="#t_firstclass">first class</a> type. If the function
5881 signature indicates the function accepts a variable number of arguments,
5882 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5883
5884 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5885 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5886 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5887</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5888
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5889<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5890<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5891 a specified function, with its incoming arguments bound to the specified
5892 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5893 function, control flow continues with the instruction after the function
5894 call, and the return value of the function is bound to the result
5895 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5896
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5897<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5898<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5899 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5900 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5901 %X = tail call i32 @foo() <i>; yields i32</i>
5902 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5903 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5904
5905 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5906 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5907 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5908 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5909 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5910 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5911</pre>
5912
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5913<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5914standard C99 library as being the C99 library functions, and may perform
5915optimizations or generate code for them under that assumption. This is
5916something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5917freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5918
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5919</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5920
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5921<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5922<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5923 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5924</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5925
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5926<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5927
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5928<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5929<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5930 &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]5931</pre>
5932
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5933<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5934<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5935 the "variable argument" area of a function call. It is used to implement the
5936 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5937
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5938<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5939<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5940 argument. It returns a value of the specified argument type and increments
5941 the <tt>va_list</tt> to point to the next argument. The actual type
5942 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5943
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5944<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5945<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5946 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5947 to the next argument. For more information, see the variable argument
5948 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5949
5950<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]5951 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5952 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5953
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5954<p><tt>va_arg</tt> is an LLVM instruction instead of
5955 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5956 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5957
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5958<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5959<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5960
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5961<p>Note that the code generator does not yet fully support va_arg on many
5962 targets. Also, it does not currently support va_arg with aggregate types on
5963 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5964
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5965</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5966
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5967</div>
5968
5969</div>
5970
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5971<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5972<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5973<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5974
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5975<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5976
5977<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5978 well known names and semantics and are required to follow certain
5979 restrictions. Overall, these intrinsics represent an extension mechanism for
5980 the LLVM language that does not require changing all of the transformations
5981 in LLVM when adding to the language (or the bitcode reader/writer, the
5982 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5983
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5984<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5985 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5986 begin with this prefix. Intrinsic functions must always be external
5987 functions: you cannot define the body of intrinsic functions. Intrinsic
5988 functions may only be used in call or invoke instructions: it is illegal to
5989 take the address of an intrinsic function. Additionally, because intrinsic
5990 functions are part of the LLVM language, it is required if any are added that
5991 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5992
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5993<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5994 family of functions that perform the same operation but on different data
5995 types. Because LLVM can represent over 8 million different integer types,
5996 overloading is used commonly to allow an intrinsic function to operate on any
5997 integer type. One or more of the argument types or the result type can be
5998 overloaded to accept any integer type. Argument types may also be defined as
5999 exactly matching a previous argument's type or the result type. This allows
6000 an intrinsic function which accepts multiple arguments, but needs all of them
6001 to be of the same type, to only be overloaded with respect to a single
6002 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6003
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6004<p>Overloaded intrinsics will have the names of its overloaded argument types
6005 encoded into its function name, each preceded by a period. Only those types
6006 which are overloaded result in a name suffix. Arguments whose type is matched
6007 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6008 can take an integer of any width and returns an integer of exactly the same
6009 integer width. This leads to a family of functions such as
6010 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6011 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6012 suffix is required. Because the argument's type is matched against the return
6013 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6014
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6015<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6016 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6017
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6018<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6019<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6020 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6021</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6022
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6023<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6024
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6025<p>Variable argument support is defined in LLVM with
6026 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6027 intrinsic functions. These functions are related to the similarly named
6028 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6029
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6030<p>All of these functions operate on arguments that use a target-specific value
6031 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6032 not define what this type is, so all transformations should be prepared to
6033 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6034
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]6035<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]6036 instruction and the variable argument handling intrinsic functions are
6037 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6038
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]6039<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6040define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6041 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6042 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6043 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6044 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6045
6046 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6047 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6048
6049 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6050 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6051 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6052 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6053 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6054
6055 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6056 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]6057 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6058}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6059
6060declare void @llvm.va_start(i8*)
6061declare void @llvm.va_copy(i8*, i8*)
6062declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6063</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6064
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6065<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6066<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6067 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6068</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6069
6070
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6071<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6072
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6073<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6074<pre>
6075 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6076</pre>
6077
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6078<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6079<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6080 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]6081
6082<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6083<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]6084
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6085<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6086<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]6087 macro available in C. In a target-dependent way, it initializes
6088 the <tt>va_list</tt> element to which the argument points, so that the next
6089 call to <tt>va_arg</tt> will produce the first variable argument passed to
6090 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6091 need to know the last argument of the function as the compiler can figure
6092 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6093
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6094</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6095
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6096<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6097<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6098 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6099</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6100
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6101<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6102
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6103<h5>Syntax:</h5>
6104<pre>
6105 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6106</pre>
6107
6108<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6109<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6110 which has been initialized previously
6111 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6112 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6113
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6114<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6115<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]6116
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6117<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6118<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]6119 macro available in C. In a target-dependent way, it destroys
6120 the <tt>va_list</tt> element to which the argument points. Calls
6121 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6122 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6123 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6124
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6125</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6126
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6127<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6128<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6129 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6130</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6131
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6132<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6133
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6134<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6135<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6136 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6137</pre>
6138
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6139<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6140<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6141 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6142
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6143<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6144<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]6145 The second argument is a pointer to a <tt>va_list</tt> element to copy
6146 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6147
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6148<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6149<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]6150 macro available in C. In a target-dependent way, it copies the
6151 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6152 element. This intrinsic is necessary because
6153 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6154 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6155
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6156</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6157
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6158</div>
6159
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6160<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6161<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6162 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6163</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6164
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6165<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6166
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6167<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]6168Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6169intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6170roots on the stack</a>, as well as garbage collector implementations that
6171require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6172barriers. Front-ends for type-safe garbage collected languages should generate
6173these intrinsics to make use of the LLVM garbage collectors. For more details,
6174see <a href="GarbageCollection.html">Accurate Garbage Collection with
6175LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6176
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6177<p>The garbage collection intrinsics only operate on objects in the generic
6178 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6179
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6180<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6181<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6182 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6183</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6184
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6185<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6186
6187<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6188<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6189 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6190</pre>
6191
6192<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]6193<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]6194 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6195
6196<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6197<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6198 root pointer. The second pointer (which must be either a constant or a
6199 global value address) contains the meta-data to be associated with the
6200 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6201
6202<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]6203<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]6204 location. At compile-time, the code generator generates information to allow
6205 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6206 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6207 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6208
6209</div>
6210
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6211<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6212<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6213 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6214</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6215
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6216<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6217
6218<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6219<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6220 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6221</pre>
6222
6223<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6224<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6225 locations, allowing garbage collector implementations that require read
6226 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6227
6228<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6229<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]6230 allocated from the garbage collector. The first object is a pointer to the
6231 start of the referenced object, if needed by the language runtime (otherwise
6232 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6233
6234<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6235<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6236 instruction, but may be replaced with substantially more complex code by the
6237 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6238 may only be used in a function which <a href="#gc">specifies a GC
6239 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6240
6241</div>
6242
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6243<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6244<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6245 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6246</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6247
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6248<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6249
6250<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6251<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6252 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6253</pre>
6254
6255<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6256<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6257 locations, allowing garbage collector implementations that require write
6258 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6259
6260<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6261<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]6262 object to store it to, and the third is the address of the field of Obj to
6263 store to. If the runtime does not require a pointer to the object, Obj may
6264 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6265
6266<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6267<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6268 instruction, but may be replaced with substantially more complex code by the
6269 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6270 may only be used in a function which <a href="#gc">specifies a GC
6271 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6272
6273</div>
6274
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6275</div>
6276
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6277<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6278<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6279 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6280</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6281
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6282<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6283
6284<p>These intrinsics are provided by LLVM to expose special features that may
6285 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6286
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6287<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6288<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6289 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6290</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6291
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6292<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6293
6294<h5>Syntax:</h5>
6295<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6296 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6297</pre>
6298
6299<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6300<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6301 target-specific value indicating the return address of the current function
6302 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6303
6304<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6305<p>The argument to this intrinsic indicates which function to return the address
6306 for. Zero indicates the calling function, one indicates its caller, etc.
6307 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6308
6309<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6310<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6311 indicating the return address of the specified call frame, or zero if it
6312 cannot be identified. The value returned by this intrinsic is likely to be
6313 incorrect or 0 for arguments other than zero, so it should only be used for
6314 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6315
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6316<p>Note that calling this intrinsic does not prevent function inlining or other
6317 aggressive transformations, so the value returned may not be that of the
6318 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6319
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6320</div>
6321
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6322<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6323<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6324 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6325</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6326
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6327<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6328
6329<h5>Syntax:</h5>
6330<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6331 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6332</pre>
6333
6334<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6335<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6336 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6337
6338<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6339<p>The argument to this intrinsic indicates which function to return the frame
6340 pointer for. Zero indicates the calling function, one indicates its caller,
6341 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6342
6343<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6344<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6345 indicating the frame address of the specified call frame, or zero if it
6346 cannot be identified. The value returned by this intrinsic is likely to be
6347 incorrect or 0 for arguments other than zero, so it should only be used for
6348 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6349
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6350<p>Note that calling this intrinsic does not prevent function inlining or other
6351 aggressive transformations, so the value returned may not be that of the
6352 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6353
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6354</div>
6355
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6356<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6357<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6358 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6359</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6360
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6361<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6362
6363<h5>Syntax:</h5>
6364<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6365 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6366</pre>
6367
6368<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6369<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6370 of the function stack, for use
6371 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6372 useful for implementing language features like scoped automatic variable
6373 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6374
6375<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6376<p>This intrinsic returns a opaque pointer value that can be passed
6377 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6378 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6379 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6380 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6381 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6382 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6383
6384</div>
6385
6386<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6387<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6388 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6389</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6390
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6391<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6392
6393<h5>Syntax:</h5>
6394<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6395 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6396</pre>
6397
6398<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6399<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6400 the function stack to the state it was in when the
6401 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6402 executed. This is useful for implementing language features like scoped
6403 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6404
6405<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6406<p>See the description
6407 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6408
6409</div>
6410
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6411<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6412<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6413 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6414</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6415
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6416<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6417
6418<h5>Syntax:</h5>
6419<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6420 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]6421</pre>
6422
6423<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6424<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6425 insert a prefetch instruction if supported; otherwise, it is a noop.
6426 Prefetches have no effect on the behavior of the program but can change its
6427 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6428
6429<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6430<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6431 specifier determining if the fetch should be for a read (0) or write (1),
6432 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6433 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6434 specifies whether the prefetch is performed on the data (1) or instruction (0)
6435 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6436 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6437
6438<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6439<p>This intrinsic does not modify the behavior of the program. In particular,
6440 prefetches cannot trap and do not produce a value. On targets that support
6441 this intrinsic, the prefetch can provide hints to the processor cache for
6442 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6443
6444</div>
6445
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6446<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6447<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6448 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6449</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6450
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6451<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6452
6453<h5>Syntax:</h5>
6454<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6455 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6456</pre>
6457
6458<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6459<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6460 Counter (PC) in a region of code to simulators and other tools. The method
6461 is target specific, but it is expected that the marker will use exported
6462 symbols to transmit the PC of the marker. The marker makes no guarantees
6463 that it will remain with any specific instruction after optimizations. It is
6464 possible that the presence of a marker will inhibit optimizations. The
6465 intended use is to be inserted after optimizations to allow correlations of
6466 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6467
6468<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6469<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6470
6471<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6472<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6473 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6474
6475</div>
6476
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6477<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6478<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6479 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6480</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6481
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6482<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6483
6484<h5>Syntax:</h5>
6485<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6486 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6487</pre>
6488
6489<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6490<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6491 counter register (or similar low latency, high accuracy clocks) on those
6492 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6493 should map to RPCC. As the backing counters overflow quickly (on the order
6494 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6495
6496<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6497<p>When directly supported, reading the cycle counter should not modify any
6498 memory. Implementations are allowed to either return a application specific
6499 value or a system wide value. On backends without support, this is lowered
6500 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6501
6502</div>
6503
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6504</div>
6505
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6506<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6507<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6508 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6509</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6510
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6511<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6512
6513<p>LLVM provides intrinsics for a few important standard C library functions.
6514 These intrinsics allow source-language front-ends to pass information about
6515 the alignment of the pointer arguments to the code generator, providing
6516 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6517
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6518<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6519<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6520 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6521</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6522
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6523<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6524
6525<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6526<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]6527 integer bit width and for different address spaces. Not all targets support
6528 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6529
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6530<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6531 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]6532 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6533 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]6534 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6535</pre>
6536
6537<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6538<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6539 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6540
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6541<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6542 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6543 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6544
6545<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6546
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6547<p>The first argument is a pointer to the destination, the second is a pointer
6548 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6549 number of bytes to copy, the fourth argument is the alignment of the
6550 source and destination locations, and the fifth is a boolean indicating a
6551 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6552
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6553<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]6554 then the caller guarantees that both the source and destination pointers are
6555 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6556
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6557<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6558 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6559 The detailed access behavior is not very cleanly specified and it is unwise
6560 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6561
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6562<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6563
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6564<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6565 source location to the destination location, which are not allowed to
6566 overlap. It copies "len" bytes of memory over. If the argument is known to
6567 be aligned to some boundary, this can be specified as the fourth argument,
6568 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6569
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6570</div>
6571
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6572<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6573<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6574 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6575</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6576
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6577<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6578
6579<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6580<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]6581 width and for different address space. Not all targets support all bit
6582 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6583
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6584<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6585 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]6586 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6587 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]6588 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6589</pre>
6590
6591<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6592<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6593 source location to the destination location. It is similar to the
6594 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6595 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6596
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6597<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6598 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6599 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6600
6601<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6602
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6603<p>The first argument is a pointer to the destination, the second is a pointer
6604 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6605 number of bytes to copy, the fourth argument is the alignment of the
6606 source and destination locations, and the fifth is a boolean indicating a
6607 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6608
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6609<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]6610 then the caller guarantees that the source and destination pointers are
6611 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6612
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6613<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6614 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6615 The detailed access behavior is not very cleanly specified and it is unwise
6616 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6617
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6618<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6619
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6620<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6621 source location to the destination location, which may overlap. It copies
6622 "len" bytes of memory over. If the argument is known to be aligned to some
6623 boundary, this can be specified as the fourth argument, otherwise it should
6624 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6625
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6626</div>
6627
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6628<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6629<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6630 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6631</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6632
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6633<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6634
6635<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6636<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]6637 width and for different address spaces. However, not all targets support all
6638 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6639
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6640<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6641 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6642 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6643 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6644 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6645</pre>
6646
6647<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6648<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6649 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6650
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6651<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6652 intrinsic does not return a value and takes extra alignment/volatile
6653 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6654
6655<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6656<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]6657 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6658 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6659 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6660
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6661<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]6662 then the caller guarantees that the destination pointer is aligned to that
6663 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6664
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6665<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6666 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6667 The detailed access behavior is not very cleanly specified and it is unwise
6668 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6669
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6670<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6671<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6672 at the destination location. If the argument is known to be aligned to some
6673 boundary, this can be specified as the fourth argument, otherwise it should
6674 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6675
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6676</div>
6677
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6678<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6679<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6680 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6681</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6682
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6683<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6684
6685<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6686<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6687 floating point or vector of floating point type. Not all targets support all
6688 types however.</p>
6689
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6690<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6691 declare float @llvm.sqrt.f32(float %Val)
6692 declare double @llvm.sqrt.f64(double %Val)
6693 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6694 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6695 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6696</pre>
6697
6698<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6699<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6700 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6701 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6702 behavior for negative numbers other than -0.0 (which allows for better
6703 optimization, because there is no need to worry about errno being
6704 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]6705
6706<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6707<p>The argument and return value are floating point numbers of the same
6708 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6709
6710<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6711<p>This function returns the sqrt of the specified operand if it is a
6712 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6713
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6714</div>
6715
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6716<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6717<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6718 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6719</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6720
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6721<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6722
6723<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6724<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6725 floating point or vector of floating point type. Not all targets support all
6726 types however.</p>
6727
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6728<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6729 declare float @llvm.powi.f32(float %Val, i32 %power)
6730 declare double @llvm.powi.f64(double %Val, i32 %power)
6731 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6732 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6733 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6734</pre>
6735
6736<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6737<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6738 specified (positive or negative) power. The order of evaluation of
6739 multiplications is not defined. When a vector of floating point type is
6740 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6741
6742<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6743<p>The second argument is an integer power, and the first is a value to raise to
6744 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6745
6746<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6747<p>This function returns the first value raised to the second power with an
6748 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6749
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6750</div>
6751
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6752<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6753<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6754 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6755</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6756
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6757<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6758
6759<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6760<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6761 floating point or vector of floating point type. Not all targets support all
6762 types however.</p>
6763
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6764<pre>
6765 declare float @llvm.sin.f32(float %Val)
6766 declare double @llvm.sin.f64(double %Val)
6767 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6768 declare fp128 @llvm.sin.f128(fp128 %Val)
6769 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6770</pre>
6771
6772<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6773<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6774
6775<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776<p>The argument and return value are floating point numbers of the same
6777 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6778
6779<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6780<p>This function returns the sine of the specified operand, returning the same
6781 values as the libm <tt>sin</tt> functions would, and handles error conditions
6782 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6783
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6784</div>
6785
6786<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6787<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6788 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6789</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6790
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6791<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6792
6793<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6794<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6795 floating point or vector of floating point type. Not all targets support all
6796 types however.</p>
6797
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6798<pre>
6799 declare float @llvm.cos.f32(float %Val)
6800 declare double @llvm.cos.f64(double %Val)
6801 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6802 declare fp128 @llvm.cos.f128(fp128 %Val)
6803 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6804</pre>
6805
6806<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6807<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6808
6809<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6810<p>The argument and return value are floating point numbers of the same
6811 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6812
6813<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6814<p>This function returns the cosine of the specified operand, returning the same
6815 values as the libm <tt>cos</tt> functions would, and handles error conditions
6816 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6817
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6818</div>
6819
6820<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6821<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6822 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6823</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6824
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6825<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6826
6827<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6828<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6829 floating point or vector of floating point type. Not all targets support all
6830 types however.</p>
6831
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6832<pre>
6833 declare float @llvm.pow.f32(float %Val, float %Power)
6834 declare double @llvm.pow.f64(double %Val, double %Power)
6835 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6836 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6837 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6838</pre>
6839
6840<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6841<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6842 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6843
6844<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6845<p>The second argument is a floating point power, and the first is a value to
6846 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6847
6848<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6849<p>This function returns the first value raised to the second power, returning
6850 the same values as the libm <tt>pow</tt> functions would, and handles error
6851 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6852
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6853</div>
6854
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6855</div>
6856
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6857<!-- _______________________________________________________________________ -->
6858<h4>
6859 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6860</h4>
6861
6862<div>
6863
6864<h5>Syntax:</h5>
6865<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6866 floating point or vector of floating point type. Not all targets support all
6867 types however.</p>
6868
6869<pre>
6870 declare float @llvm.exp.f32(float %Val)
6871 declare double @llvm.exp.f64(double %Val)
6872 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6873 declare fp128 @llvm.exp.f128(fp128 %Val)
6874 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6875</pre>
6876
6877<h5>Overview:</h5>
6878<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6879
6880<h5>Arguments:</h5>
6881<p>The argument and return value are floating point numbers of the same
6882 type.</p>
6883
6884<h5>Semantics:</h5>
6885<p>This function returns the same values as the libm <tt>exp</tt> functions
6886 would, and handles error conditions in the same way.</p>
6887
6888</div>
6889
6890<!-- _______________________________________________________________________ -->
6891<h4>
6892 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6893</h4>
6894
6895<div>
6896
6897<h5>Syntax:</h5>
6898<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6899 floating point or vector of floating point type. Not all targets support all
6900 types however.</p>
6901
6902<pre>
6903 declare float @llvm.log.f32(float %Val)
6904 declare double @llvm.log.f64(double %Val)
6905 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6906 declare fp128 @llvm.log.f128(fp128 %Val)
6907 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6908</pre>
6909
6910<h5>Overview:</h5>
6911<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6912
6913<h5>Arguments:</h5>
6914<p>The argument and return value are floating point numbers of the same
6915 type.</p>
6916
6917<h5>Semantics:</h5>
6918<p>This function returns the same values as the libm <tt>log</tt> functions
6919 would, and handles error conditions in the same way.</p>
6920
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6921<h4>
6922 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6923</h4>
6924
6925<div>
6926
6927<h5>Syntax:</h5>
6928<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6929 floating point or vector of floating point type. Not all targets support all
6930 types however.</p>
6931
6932<pre>
6933 declare float @llvm.fma.f32(float %a, float %b, float %c)
6934 declare double @llvm.fma.f64(double %a, double %b, double %c)
6935 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6936 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6937 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6938</pre>
6939
6940<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]6941<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6942 operation.</p>
6943
6944<h5>Arguments:</h5>
6945<p>The argument and return value are floating point numbers of the same
6946 type.</p>
6947
6948<h5>Semantics:</h5>
6949<p>This function returns the same values as the libm <tt>fma</tt> functions
6950 would.</p>
6951
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6952</div>
6953
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6954<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6955<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6956 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6957</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6958
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6959<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6960
6961<p>LLVM provides intrinsics for a few important bit manipulation operations.
6962 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6963
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6964<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6965<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6966 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6967</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6968
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6969<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6970
6971<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6972<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6973 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6974
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6975<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6976 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6977 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6978 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6979</pre>
6980
6981<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6982<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6983 values with an even number of bytes (positive multiple of 16 bits). These
6984 are useful for performing operations on data that is not in the target's
6985 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6986
6987<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6988<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6989 and low byte of the input i16 swapped. Similarly,
6990 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6991 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6992 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6993 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6994 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6995 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6996
6997</div>
6998
6999<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7000<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]7001 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7002</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7003
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7004<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7005
7006<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]7007<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]7008 width, or on any vector with integer elements. Not all targets support all
7009 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7010
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7011<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7012 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7013 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7014 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7015 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7016 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7017 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]7018</pre>
7019
7020<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7021<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7022 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7023
7024<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7025<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]7026 integer type, or a vector with integer elements.
7027 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7028
7029<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7030<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7031 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7032
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7033</div>
7034
7035<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7036<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7037 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7038</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7039
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7040<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7041
7042<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7043<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]7044 integer bit width, or any vector whose elements are integers. Not all
7045 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7046
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7047<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7048 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7049 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7050 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7051 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7052 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7053 declare &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src;gt)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7054</pre>
7055
7056<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7057<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7058 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7059
7060<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7061<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]7062 integer type, or any vector type with integer element type.
7063 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7064
7065<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7066<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7067 zeros in a variable, or within each element of the vector if the operation
7068 is of vector type. If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7069 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7070
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7071</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]7072
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7073<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7074<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7075 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7076</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7077
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7078<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7079
7080<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7081<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]7082 integer bit width, or any vector of integer elements. Not all targets
7083 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7084
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7085<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7086 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7087 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7088 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7089 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7090 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7091 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7092</pre>
7093
7094<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7095<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7096 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7097
7098<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7099<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]7100 integer type, or a vectory with integer element type.. The return type
7101 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7102
7103<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7104<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7105 zeros in a variable, or within each element of a vector.
7106 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7107 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7108
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7109</div>
7110
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7111</div>
7112
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7113<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7114<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7115 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7116</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7117
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7118<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7119
7120<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7121
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7122<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7123<h4>
7124 <a name="int_sadd_overflow">
7125 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7126 </a>
7127</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7128
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7129<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7130
7131<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7132<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]7133 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7134
7135<pre>
7136 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7137 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7138 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7139</pre>
7140
7141<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7142<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7143 a signed addition of the two arguments, and indicate whether an overflow
7144 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7145
7146<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7147<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]7148 be of integer types of any bit width, but they must have the same bit
7149 width. The second element of the result structure must be of
7150 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7151 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7152
7153<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7154<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7155 a signed addition of the two variables. They return a structure &mdash; the
7156 first element of which is the signed summation, and the second element of
7157 which is a bit specifying if the signed summation resulted in an
7158 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7159
7160<h5>Examples:</h5>
7161<pre>
7162 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7163 %sum = extractvalue {i32, i1} %res, 0
7164 %obit = extractvalue {i32, i1} %res, 1
7165 br i1 %obit, label %overflow, label %normal
7166</pre>
7167
7168</div>
7169
7170<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7171<h4>
7172 <a name="int_uadd_overflow">
7173 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7174 </a>
7175</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7176
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7177<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7178
7179<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7180<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]7181 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7182
7183<pre>
7184 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7185 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7186 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7187</pre>
7188
7189<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7190<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7191 an unsigned addition of the two arguments, and indicate whether a carry
7192 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7193
7194<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7195<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]7196 be of integer types of any bit width, but they must have the same bit
7197 width. The second element of the result structure must be of
7198 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7199 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7200
7201<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7202<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7203 an unsigned addition of the two arguments. They return a structure &mdash;
7204 the first element of which is the sum, and the second element of which is a
7205 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7206
7207<h5>Examples:</h5>
7208<pre>
7209 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7210 %sum = extractvalue {i32, i1} %res, 0
7211 %obit = extractvalue {i32, i1} %res, 1
7212 br i1 %obit, label %carry, label %normal
7213</pre>
7214
7215</div>
7216
7217<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7218<h4>
7219 <a name="int_ssub_overflow">
7220 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7221 </a>
7222</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7223
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7224<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7225
7226<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7227<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]7228 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7229
7230<pre>
7231 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7232 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7233 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7234</pre>
7235
7236<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7237<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7238 a signed subtraction of the two arguments, and indicate whether an overflow
7239 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7240
7241<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7242<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]7243 be of integer types of any bit width, but they must have the same bit
7244 width. The second element of the result structure must be of
7245 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7246 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7247
7248<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7249<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7250 a signed subtraction of the two arguments. They return a structure &mdash;
7251 the first element of which is the subtraction, and the second element of
7252 which is a bit specifying if the signed subtraction resulted in an
7253 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7254
7255<h5>Examples:</h5>
7256<pre>
7257 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7258 %sum = extractvalue {i32, i1} %res, 0
7259 %obit = extractvalue {i32, i1} %res, 1
7260 br i1 %obit, label %overflow, label %normal
7261</pre>
7262
7263</div>
7264
7265<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7266<h4>
7267 <a name="int_usub_overflow">
7268 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7269 </a>
7270</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7271
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7272<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7273
7274<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7275<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]7276 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7277
7278<pre>
7279 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7280 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7281 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7282</pre>
7283
7284<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7285<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7286 an unsigned subtraction of the two arguments, and indicate whether an
7287 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7288
7289<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7290<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]7291 be of integer types of any bit width, but they must have the same bit
7292 width. The second element of the result structure must be of
7293 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7294 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7295
7296<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7297<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7298 an unsigned subtraction of the two arguments. They return a structure &mdash;
7299 the first element of which is the subtraction, and the second element of
7300 which is a bit specifying if the unsigned subtraction resulted in an
7301 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7302
7303<h5>Examples:</h5>
7304<pre>
7305 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7306 %sum = extractvalue {i32, i1} %res, 0
7307 %obit = extractvalue {i32, i1} %res, 1
7308 br i1 %obit, label %overflow, label %normal
7309</pre>
7310
7311</div>
7312
7313<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7314<h4>
7315 <a name="int_smul_overflow">
7316 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7317 </a>
7318</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7319
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7320<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7321
7322<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7323<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]7324 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7325
7326<pre>
7327 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7328 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7329 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7330</pre>
7331
7332<h5>Overview:</h5>
7333
7334<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7335 a signed multiplication of the two arguments, and indicate whether an
7336 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7337
7338<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7339<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]7340 be of integer types of any bit width, but they must have the same bit
7341 width. The second element of the result structure must be of
7342 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7343 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7344
7345<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7346<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7347 a signed multiplication of the two arguments. They return a structure &mdash;
7348 the first element of which is the multiplication, and the second element of
7349 which is a bit specifying if the signed multiplication resulted in an
7350 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7351
7352<h5>Examples:</h5>
7353<pre>
7354 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7355 %sum = extractvalue {i32, i1} %res, 0
7356 %obit = extractvalue {i32, i1} %res, 1
7357 br i1 %obit, label %overflow, label %normal
7358</pre>
7359
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7360</div>
7361
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7362<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7363<h4>
7364 <a name="int_umul_overflow">
7365 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7366 </a>
7367</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7368
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7369<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7370
7371<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7372<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]7373 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7374
7375<pre>
7376 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7377 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7378 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7379</pre>
7380
7381<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7382<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7383 a unsigned multiplication of the two arguments, and indicate whether an
7384 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7385
7386<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7387<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]7388 be of integer types of any bit width, but they must have the same bit
7389 width. The second element of the result structure must be of
7390 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7391 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7392
7393<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7394<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7395 an unsigned multiplication of the two arguments. They return a structure
7396 &mdash; the first element of which is the multiplication, and the second
7397 element of which is a bit specifying if the unsigned multiplication resulted
7398 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7399
7400<h5>Examples:</h5>
7401<pre>
7402 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7403 %sum = extractvalue {i32, i1} %res, 0
7404 %obit = extractvalue {i32, i1} %res, 1
7405 br i1 %obit, label %overflow, label %normal
7406</pre>
7407
7408</div>
7409
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7410</div>
7411
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7412<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7413<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7414 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7415</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7416
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7417<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7418
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7419<p>Half precision floating point is a storage-only format. This means that it is
7420 a dense encoding (in memory) but does not support computation in the
7421 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7422
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7423<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7424 value as an i16, then convert it to float with <a
7425 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7426 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7427 double etc). To store the value back to memory, it is first converted to
7428 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7429 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7430 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7431
7432<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7433<h4>
7434 <a name="int_convert_to_fp16">
7435 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7436 </a>
7437</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7438
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7439<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7440
7441<h5>Syntax:</h5>
7442<pre>
7443 declare i16 @llvm.convert.to.fp16(f32 %a)
7444</pre>
7445
7446<h5>Overview:</h5>
7447<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7448 a conversion from single precision floating point format to half precision
7449 floating point format.</p>
7450
7451<h5>Arguments:</h5>
7452<p>The intrinsic function contains single argument - the value to be
7453 converted.</p>
7454
7455<h5>Semantics:</h5>
7456<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7457 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7458 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7459 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7460
7461<h5>Examples:</h5>
7462<pre>
7463 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7464 store i16 %res, i16* @x, align 2
7465</pre>
7466
7467</div>
7468
7469<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7470<h4>
7471 <a name="int_convert_from_fp16">
7472 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7473 </a>
7474</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7475
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7476<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7477
7478<h5>Syntax:</h5>
7479<pre>
7480 declare f32 @llvm.convert.from.fp16(i16 %a)
7481</pre>
7482
7483<h5>Overview:</h5>
7484<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7485 a conversion from half precision floating point format to single precision
7486 floating point format.</p>
7487
7488<h5>Arguments:</h5>
7489<p>The intrinsic function contains single argument - the value to be
7490 converted.</p>
7491
7492<h5>Semantics:</h5>
7493<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7494 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7495 precision floating point format. The input half-float value is represented by
7496 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7497
7498<h5>Examples:</h5>
7499<pre>
7500 %a = load i16* @x, align 2
7501 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7502</pre>
7503
7504</div>
7505
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7506</div>
7507
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7508<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7509<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7510 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7511</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7512
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7513<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7514
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7515<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7516 prefix), are described in
7517 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7518 Level Debugging</a> document.</p>
7519
7520</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7521
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7522<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7523<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7524 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7525</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7526
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7527<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7528
7529<p>The LLVM exception handling intrinsics (which all start with
7530 <tt>llvm.eh.</tt> prefix), are described in
7531 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7532 Handling</a> document.</p>
7533
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7534</div>
7535
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7536<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7537<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7538 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7539</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7540
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7541<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7542
7543<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7544 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7545 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7546 function pointer lacking the nest parameter - the caller does not need to
7547 provide a value for it. Instead, the value to use is stored in advance in a
7548 "trampoline", a block of memory usually allocated on the stack, which also
7549 contains code to splice the nest value into the argument list. This is used
7550 to implement the GCC nested function address extension.</p>
7551
7552<p>For example, if the function is
7553 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7554 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7555 follows:</p>
7556
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7557<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7558 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7559 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7560 %p = call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval)
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7561 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7562</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7563
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7564<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7565 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7566
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7567<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7568<h4>
7569 <a name="int_it">
7570 '<tt>llvm.init.trampoline</tt>' Intrinsic
7571 </a>
7572</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7573
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7574<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7575
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7576<h5>Syntax:</h5>
7577<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7578 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7579</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7580
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7581<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7582<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7583 function pointer suitable for executing it.</p>
7584
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7585<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7586<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7587 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7588 sufficiently aligned block of memory; this memory is written to by the
7589 intrinsic. Note that the size and the alignment are target-specific - LLVM
7590 currently provides no portable way of determining them, so a front-end that
7591 generates this intrinsic needs to have some target-specific knowledge.
7592 The <tt>func</tt> argument must hold a function bitcast to
7593 an <tt>i8*</tt>.</p>
7594
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7595<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7596<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7597 dependent code, turning it into a function. A pointer to this function is
7598 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7599 function pointer type</a> before being called. The new function's signature
7600 is the same as that of <tt>func</tt> with any arguments marked with
7601 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7602 is allowed, and it must be of pointer type. Calling the new function is
7603 equivalent to calling <tt>func</tt> with the same argument list, but
7604 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7605 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7606 by <tt>tramp</tt> is modified, then the effect of any later call to the
7607 returned function pointer is undefined.</p>
7608
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7609</div>
7610
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7611</div>
7612
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7613<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7614<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7615 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7616</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7617
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7618<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7619
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7620<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7621 hardware constructs for atomic operations and memory synchronization. This
7622 provides an interface to the hardware, not an interface to the programmer. It
7623 is aimed at a low enough level to allow any programming models or APIs
7624 (Application Programming Interfaces) which need atomic behaviors to map
7625 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7626 hardware provides a "universal IR" for source languages, it also provides a
7627 starting point for developing a "universal" atomic operation and
7628 synchronization IR.</p>
7629
7630<p>These do <em>not</em> form an API such as high-level threading libraries,
7631 software transaction memory systems, atomic primitives, and intrinsic
7632 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7633 application libraries. The hardware interface provided by LLVM should allow
7634 a clean implementation of all of these APIs and parallel programming models.
7635 No one model or paradigm should be selected above others unless the hardware
7636 itself ubiquitously does so.</p>
7637
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7638<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7639<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7640 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7641</h4>
7642
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7643<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7644<h5>Syntax:</h5>
7645<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7646 declare void @llvm.memory.barrier(i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt;)
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7647</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7648
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7649<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7650<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7651 specific pairs of memory access types.</p>
7652
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7653<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7654<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7655 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7656 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7657 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7658
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7659<ul>
7660 <li><tt>ll</tt>: load-load barrier</li>
7661 <li><tt>ls</tt>: load-store barrier</li>
7662 <li><tt>sl</tt>: store-load barrier</li>
7663 <li><tt>ss</tt>: store-store barrier</li>
7664 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7665</ul>
7666
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7667<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7668<p>This intrinsic causes the system to enforce some ordering constraints upon
7669 the loads and stores of the program. This barrier does not
7670 indicate <em>when</em> any events will occur, it only enforces
7671 an <em>order</em> in which they occur. For any of the specified pairs of load
7672 and store operations (f.ex. load-load, or store-load), all of the first
7673 operations preceding the barrier will complete before any of the second
7674 operations succeeding the barrier begin. Specifically the semantics for each
7675 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7676
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7677<ul>
7678 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7679 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7680 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7681 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7682 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7683 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7684 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7685 load after the barrier begins.</li>
7686</ul>
7687
7688<p>These semantics are applied with a logical "and" behavior when more than one
7689 is enabled in a single memory barrier intrinsic.</p>
7690
7691<p>Backends may implement stronger barriers than those requested when they do
7692 not support as fine grained a barrier as requested. Some architectures do
7693 not need all types of barriers and on such architectures, these become
7694 noops.</p>
7695
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7696<h5>Example:</h5>
7697<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7698%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7699%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7700 store i32 4, %ptr
7701
7702%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7703 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7704 <i>; guarantee the above finishes</i>
7705 store i32 8, %ptr <i>; before this begins</i>
7706</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7707
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7708</div>
7709
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7710<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7711<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7712 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7713</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7714
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7715<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7716
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7717<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7718<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7719 any integer bit width and for different address spaces. Not all targets
7720 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7721
7722<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7723 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7724 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7725 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7726 declare i64 @llvm.atomic.cmp.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt;)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7727</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7728
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7729<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7730<p>This loads a value in memory and compares it to a given value. If they are
7731 equal, it stores a new value into the memory.</p>
7732
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7733<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7734<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7735 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7736 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7737 this integer type. While any bit width integer may be used, targets may only
7738 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7739
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7740<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7741<p>This entire intrinsic must be executed atomically. It first loads the value
7742 in memory pointed to by <tt>ptr</tt> and compares it with the
7743 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7744 memory. The loaded value is yielded in all cases. This provides the
7745 equivalent of an atomic compare-and-swap operation within the SSA
7746 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7747
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7748<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7749<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7750%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7751%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7752 store i32 4, %ptr
7753
7754%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7755%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7756 <i>; yields {i32}:result1 = 4</i>
7757%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7758%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7759
7760%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7761%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7762 <i>; yields {i32}:result2 = 8</i>
7763%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7764
7765%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7766</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7767
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7768</div>
7769
7770<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7771<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7772 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7773</h4>
7774
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7775<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7776<h5>Syntax:</h5>
7777
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7778<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7779 integer bit width. Not all targets support all bit widths however.</p>
7780
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7781<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7782 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7783 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7784 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7785 declare i64 @llvm.atomic.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;val&gt;)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7786</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7787
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7788<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7789<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7790 the value from memory. It then stores the value in <tt>val</tt> in the memory
7791 at <tt>ptr</tt>.</p>
7792
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7793<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7794<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7795 the <tt>val</tt> argument and the result must be integers of the same bit
7796 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7797 integer type. The targets may only lower integer representations they
7798 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7799
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7800<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7801<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7802 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7803 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7804
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7805<h5>Examples:</h5>
7806<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7807%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7808%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7809 store i32 4, %ptr
7810
7811%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7812%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7813 <i>; yields {i32}:result1 = 4</i>
7814%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7815%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7816
7817%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7818%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7819 <i>; yields {i32}:result2 = 8</i>
7820
7821%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7822%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7823</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7824
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7825</div>
7826
7827<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7828<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7829 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7830</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7831
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7832<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7833
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7834<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7835<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7836 any integer bit width. Not all targets support all bit widths however.</p>
7837
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7838<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7839 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7840 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7841 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7842 declare i64 @llvm.atomic.load.add.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7843</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7844
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7845<h5>Overview:</h5>
7846<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7847 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7848
7849<h5>Arguments:</h5>
7850<p>The intrinsic takes two arguments, the first a pointer to an integer value
7851 and the second an integer value. The result is also an integer value. These
7852 integer types can have any bit width, but they must all have the same bit
7853 width. The targets may only lower integer representations they support.</p>
7854
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7855<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7856<p>This intrinsic does a series of operations atomically. It first loads the
7857 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7858 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7859
7860<h5>Examples:</h5>
7861<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7862%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7863%ptr = bitcast i8* %mallocP to i32*
7864 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7865%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7866 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7867%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7868 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7869%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7870 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7871%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7872</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7873
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7874</div>
7875
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7876<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7877<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7878 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7879</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7880
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7881<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7882
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7883<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7884<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7885 any integer bit width and for different address spaces. Not all targets
7886 support all bit widths however.</p>
7887
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7888<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7889 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7890 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7891 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7892 declare i64 @llvm.atomic.load.sub.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7893</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7894
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7895<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7896<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7897 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7898
7899<h5>Arguments:</h5>
7900<p>The intrinsic takes two arguments, the first a pointer to an integer value
7901 and the second an integer value. The result is also an integer value. These
7902 integer types can have any bit width, but they must all have the same bit
7903 width. The targets may only lower integer representations they support.</p>
7904
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7905<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7906<p>This intrinsic does a series of operations atomically. It first loads the
7907 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7908 result to <tt>ptr</tt>. It yields the original value stored
7909 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7910
7911<h5>Examples:</h5>
7912<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7913%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7914%ptr = bitcast i8* %mallocP to i32*
7915 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7916%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7917 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7918%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7919 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7920%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7921 <i>; yields {i32}:result3 = 2</i>
7922%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7923</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7924
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7925</div>
7926
7927<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7928<h4>
7929 <a name="int_atomic_load_and">
7930 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7931 </a>
7932 <br>
7933 <a name="int_atomic_load_nand">
7934 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7935 </a>
7936 <br>
7937 <a name="int_atomic_load_or">
7938 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7939 </a>
7940 <br>
7941 <a name="int_atomic_load_xor">
7942 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7943 </a>
7944</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7945
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7946<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7947
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7948<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7949<p>These are overloaded intrinsics. You can
7950 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7951 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7952 bit width and for different address spaces. Not all targets support all bit
7953 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7954
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7955<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7956 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7957 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7958 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7959 declare i64 @llvm.atomic.load.and.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7960</pre>
7961
7962<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7963 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7964 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7965 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7966 declare i64 @llvm.atomic.load.or.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7967</pre>
7968
7969<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7970 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7971 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7972 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7973 declare i64 @llvm.atomic.load.nand.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7974</pre>
7975
7976<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7977 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7978 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7979 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7980 declare i64 @llvm.atomic.load.xor.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7981</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7982
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7983<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7984<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7985 the value stored in memory at <tt>ptr</tt>. It yields the original value
7986 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7987
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7988<h5>Arguments:</h5>
7989<p>These intrinsics take two arguments, the first a pointer to an integer value
7990 and the second an integer value. The result is also an integer value. These
7991 integer types can have any bit width, but they must all have the same bit
7992 width. The targets may only lower integer representations they support.</p>
7993
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7994<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7995<p>These intrinsics does a series of operations atomically. They first load the
7996 value stored at <tt>ptr</tt>. They then do the bitwise
7997 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7998 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7999
8000<h5>Examples:</h5>
8001<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]8002%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8003%ptr = bitcast i8* %mallocP to i32*
8004 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8005%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8006 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8007%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8008 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8009%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8010 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8011%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8012 <i>; yields {i32}:result3 = FF</i>
8013%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
8014</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8015
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8016</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8017
8018<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8019<h4>
8020 <a name="int_atomic_load_max">
8021 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
8022 </a>
8023 <br>
8024 <a name="int_atomic_load_min">
8025 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
8026 </a>
8027 <br>
8028 <a name="int_atomic_load_umax">
8029 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
8030 </a>
8031 <br>
8032 <a name="int_atomic_load_umin">
8033 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8034 </a>
8035</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8036
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8037<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8038
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8039<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8040<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8041 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8042 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8043 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8044
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8045<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8046 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8047 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8048 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8049 declare i64 @llvm.atomic.load.max.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8050</pre>
8051
8052<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8053 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8054 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8055 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8056 declare i64 @llvm.atomic.load.min.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8057</pre>
8058
8059<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8060 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8061 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8062 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8063 declare i64 @llvm.atomic.load.umax.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8064</pre>
8065
8066<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8067 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8068 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8069 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8070 declare i64 @llvm.atomic.load.umin.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8071</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8072
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8073<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8074<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8075 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8076 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8077
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8078<h5>Arguments:</h5>
8079<p>These intrinsics take two arguments, the first a pointer to an integer value
8080 and the second an integer value. The result is also an integer value. These
8081 integer types can have any bit width, but they must all have the same bit
8082 width. The targets may only lower integer representations they support.</p>
8083
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8084<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8085<p>These intrinsics does a series of operations atomically. They first load the
8086 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8087 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8088 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8089
8090<h5>Examples:</h5>
8091<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]8092%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8093%ptr = bitcast i8* %mallocP to i32*
8094 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8095%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8096 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8097%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8098 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8099%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8100 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8101%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8102 <i>; yields {i32}:result3 = 8</i>
8103%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8104</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8105
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8106</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8107
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8108</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8109
8110<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8111<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8112 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8113</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8114
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8115<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8116
8117<p>This class of intrinsics exists to information about the lifetime of memory
8118 objects and ranges where variables are immutable.</p>
8119
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8120<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8121<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8122 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8123</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8124
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8125<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8126
8127<h5>Syntax:</h5>
8128<pre>
8129 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8130</pre>
8131
8132<h5>Overview:</h5>
8133<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8134 object's lifetime.</p>
8135
8136<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8137<p>The first argument is a constant integer representing the size of the
8138 object, or -1 if it is variable sized. The second argument is a pointer to
8139 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8140
8141<h5>Semantics:</h5>
8142<p>This intrinsic indicates that before this point in the code, the value of the
8143 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]8144 never be used and has an undefined value. A load from the pointer that
8145 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8146 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8147
8148</div>
8149
8150<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8151<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8152 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8153</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8154
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8155<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8156
8157<h5>Syntax:</h5>
8158<pre>
8159 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8160</pre>
8161
8162<h5>Overview:</h5>
8163<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8164 object's lifetime.</p>
8165
8166<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8167<p>The first argument is a constant integer representing the size of the
8168 object, or -1 if it is variable sized. The second argument is a pointer to
8169 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8170
8171<h5>Semantics:</h5>
8172<p>This intrinsic indicates that after this point in the code, the value of the
8173 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8174 never be used and has an undefined value. Any stores into the memory object
8175 following this intrinsic may be removed as dead.
8176
8177</div>
8178
8179<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8180<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8181 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8182</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8183
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8184<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8185
8186<h5>Syntax:</h5>
8187<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]8188 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8189</pre>
8190
8191<h5>Overview:</h5>
8192<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8193 a memory object will not change.</p>
8194
8195<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8196<p>The first argument is a constant integer representing the size of the
8197 object, or -1 if it is variable sized. The second argument is a pointer to
8198 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8199
8200<h5>Semantics:</h5>
8201<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8202 the return value, the referenced memory location is constant and
8203 unchanging.</p>
8204
8205</div>
8206
8207<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8208<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8209 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8210</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8211
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8212<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8213
8214<h5>Syntax:</h5>
8215<pre>
8216 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8217</pre>
8218
8219<h5>Overview:</h5>
8220<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8221 a memory object are mutable.</p>
8222
8223<h5>Arguments:</h5>
8224<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8225 The second argument is a constant integer representing the size of the
8226 object, or -1 if it is variable sized and the third argument is a pointer
8227 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8228
8229<h5>Semantics:</h5>
8230<p>This intrinsic indicates that the memory is mutable again.</p>
8231
8232</div>
8233
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8234</div>
8235
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8236<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8237<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8238 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8239</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8240
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8241<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8242
8243<p>This class of intrinsics is designed to be generic and has no specific
8244 purpose.</p>
8245
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8246<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8247<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8248 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8249</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8250
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8251<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8252
8253<h5>Syntax:</h5>
8254<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8255 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]8256</pre>
8257
8258<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8259<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8260
8261<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8262<p>The first argument is a pointer to a value, the second is a pointer to a
8263 global string, the third is a pointer to a global string which is the source
8264 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8265
8266<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8267<p>This intrinsic allows annotation of local variables with arbitrary strings.
8268 This can be useful for special purpose optimizations that want to look for
8269 these annotations. These have no other defined use, they are ignored by code
8270 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8271
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8272</div>
8273
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8274<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8275<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]8276 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8277</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8278
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8279<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8280
8281<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8282<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8283 any integer bit width.</p>
8284
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8285<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8286 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8287 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8288 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8289 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8290 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]8291</pre>
8292
8293<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8294<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8295
8296<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8297<p>The first argument is an integer value (result of some expression), the
8298 second is a pointer to a global string, the third is a pointer to a global
8299 string which is the source file name, and the last argument is the line
8300 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8301
8302<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8303<p>This intrinsic allows annotations to be put on arbitrary expressions with
8304 arbitrary strings. This can be useful for special purpose optimizations that
8305 want to look for these annotations. These have no other defined use, they
8306 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8307
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8308</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8309
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8310<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8311<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8312 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8313</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8314
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8315<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8316
8317<h5>Syntax:</h5>
8318<pre>
8319 declare void @llvm.trap()
8320</pre>
8321
8322<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8323<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8324
8325<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8326<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8327
8328<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8329<p>This intrinsics is lowered to the target dependent trap instruction. If the
8330 target does not have a trap instruction, this intrinsic will be lowered to
8331 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8332
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8333</div>
8334
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8335<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8336<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]8337 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8338</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8339
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8340<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8341
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8342<h5>Syntax:</h5>
8343<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8344 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8345</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8346
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8347<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8348<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8349 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8350 ensure that it is placed on the stack before local variables.</p>
8351
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8352<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8353<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8354 arguments. The first argument is the value loaded from the stack
8355 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8356 that has enough space to hold the value of the guard.</p>
8357
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8358<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8359<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8360 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8361 stack. This is to ensure that if a local variable on the stack is
8362 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8363 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8364 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8365 function.</p>
8366
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8367</div>
8368
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8369<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8370<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8371 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8372</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8373
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8374<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8375
8376<h5>Syntax:</h5>
8377<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8378 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8379 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8380</pre>
8381
8382<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8383<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8384 the optimizers to determine at compile time whether a) an operation (like
8385 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8386 runtime check for overflow isn't necessary. An object in this context means
8387 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8388
8389<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8390<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8391 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8392 is a boolean 0 or 1. This argument determines whether you want the
8393 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8394 1, variables are not allowed.</p>
8395
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8396<h5>Semantics:</h5>
8397<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8398 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8399 depending on the <tt>type</tt> argument, if the size cannot be determined at
8400 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8401
8402</div>
8403
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8404</div>
8405
8406</div>
8407
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8408<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8409<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8410<address>
8411 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8412 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8413 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8414 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]8415
8416 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8417 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8418 Last modified: $Date$
8419</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8420
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8421</body>
8422</html>