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gerrit-public.fairphone.software / toolchain / llvm-project / 6c923bb8d9bb0cb7067cb8c7b001ccd19bcfd8ac / . / 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.">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
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>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]57 </ol>
58 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]59 <li><a href="#typesystem">Type System</a>
60 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]62 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]63 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]64 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]65 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]66 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]67 <li><a href="#t_void">Void Type</a></li>
68 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]69 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]70 </ol>
71 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]72 <li><a href="#t_derived">Derived Types</a>
73 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]74 <li><a href="#t_aggregate">Aggregate Types</a>
75 <ol>
76 <li><a href="#t_array">Array Type</a></li>
77 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]78 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]79 <li><a href="#t_vector">Vector Type</a></li>
80 </ol>
81 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]82 <li><a href="#t_function">Function Type</a></li>
83 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
86 </ol>
87 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]88 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]89 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]90 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]91 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
93 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]94 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]95 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]96 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]97 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]98 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]99 <li><a href="#othervalues">Other Values</a>
100 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]101 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]102 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]103 </ol>
104 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]105 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
106 <ol>
107 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]108 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
109 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]110 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
111 Global Variable</a></li>
112 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
113 Global Variable</a></li>
114 </ol>
115 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]116 <li><a href="#instref">Instruction Reference</a>
117 <ol>
118 <li><a href="#terminators">Terminator Instructions</a>
119 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
121 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]122 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]123 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]124 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Bill Wendling6c923bb2011-07-27 20:18:04 +0000[diff] [blame^]126 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]127 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]128 </ol>
129 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]130 <li><a href="#binaryops">Binary Operations</a>
131 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]136 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]137 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]138 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
139 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
140 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]141 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
142 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
143 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]144 </ol>
145 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]146 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
147 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]148 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
149 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
150 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]152 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]153 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]154 </ol>
155 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]156 <li><a href="#vectorops">Vector Operations</a>
157 <ol>
158 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
159 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
160 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]161 </ol>
162 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]163 <li><a href="#aggregateops">Aggregate Operations</a>
164 <ol>
165 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
166 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
167 </ol>
168 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]169 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]170 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]171 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]172 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
173 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]174 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]175 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]176 </ol>
177 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]178 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]179 <ol>
180 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
181 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
182 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
184 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]185 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
186 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
187 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
188 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]189 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
190 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]191 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]192 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]193 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]194 <li><a href="#otherops">Other Operations</a>
195 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]196 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
197 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]198 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]199 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]200 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]201 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]202 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]203 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]204 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]205 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]206 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]207 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]208 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
209 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]210 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
211 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
212 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]213 </ol>
214 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]215 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
216 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]217 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
218 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
219 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]220 </ol>
221 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]222 <li><a href="#int_codegen">Code Generator Intrinsics</a>
223 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]224 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
225 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
226 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
227 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
228 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
229 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]230 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]231 </ol>
232 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]233 <li><a href="#int_libc">Standard C Library Intrinsics</a>
234 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]235 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]240 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]243 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
244 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]245 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]246 </ol>
247 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]248 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]249 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]250 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]251 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
252 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
253 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]254 </ol>
255 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]256 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
257 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]258 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
260 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
261 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
262 <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]263 <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]264 </ol>
265 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]266 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
267 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]268 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
269 <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]270 </ol>
271 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]272 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]273 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]274 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]275 <ol>
276 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]277 </ol>
278 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]279 <li><a href="#int_atomics">Atomic intrinsics</a>
280 <ol>
281 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
282 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
283 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
284 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
285 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
286 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
287 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
288 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
289 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
290 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
291 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
292 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
293 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
294 </ol>
295 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]296 <li><a href="#int_memorymarkers">Memory Use Markers</a>
297 <ol>
298 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
299 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
300 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
301 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
302 </ol>
303 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]304 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]305 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]306 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]307 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]308 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]310 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]311 '<tt>llvm.trap</tt>' Intrinsic</a></li>
312 <li><a href="#int_stackprotector">
313 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]314 <li><a href="#int_objectsize">
315 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]316 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]317 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]318 </ol>
319 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]320</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]321
322<div class="doc_author">
323 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
324 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]325</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]327<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]328<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]329<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]330
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]331<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]332
333<p>This document is a reference manual for the LLVM assembly language. LLVM is
334 a Static Single Assignment (SSA) based representation that provides type
335 safety, low-level operations, flexibility, and the capability of representing
336 'all' high-level languages cleanly. It is the common code representation
337 used throughout all phases of the LLVM compilation strategy.</p>
338
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]339</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]340
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]341<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]342<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]343<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]344
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]345<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]346
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]347<p>The LLVM code representation is designed to be used in three different forms:
348 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
349 for fast loading by a Just-In-Time compiler), and as a human readable
350 assembly language representation. This allows LLVM to provide a powerful
351 intermediate representation for efficient compiler transformations and
352 analysis, while providing a natural means to debug and visualize the
353 transformations. The three different forms of LLVM are all equivalent. This
354 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]355
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]356<p>The LLVM representation aims to be light-weight and low-level while being
357 expressive, typed, and extensible at the same time. It aims to be a
358 "universal IR" of sorts, by being at a low enough level that high-level ideas
359 may be cleanly mapped to it (similar to how microprocessors are "universal
360 IR's", allowing many source languages to be mapped to them). By providing
361 type information, LLVM can be used as the target of optimizations: for
362 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]363 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]364 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]365
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]366<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]367<h4>
368 <a name="wellformed">Well-Formedness</a>
369</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]370
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]371<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]372
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]373<p>It is important to note that this document describes 'well formed' LLVM
374 assembly language. There is a difference between what the parser accepts and
375 what is considered 'well formed'. For example, the following instruction is
376 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]377
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]378<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]379%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]380</pre>
381
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]382<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
383 LLVM infrastructure provides a verification pass that may be used to verify
384 that an LLVM module is well formed. This pass is automatically run by the
385 parser after parsing input assembly and by the optimizer before it outputs
386 bitcode. The violations pointed out by the verifier pass indicate bugs in
387 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]388
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]389</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]390
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]391</div>
392
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]393<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]394
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]395<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]396<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]397<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]398
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]399<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]400
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]401<p>LLVM identifiers come in two basic types: global and local. Global
402 identifiers (functions, global variables) begin with the <tt>'@'</tt>
403 character. Local identifiers (register names, types) begin with
404 the <tt>'%'</tt> character. Additionally, there are three different formats
405 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]406
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]407<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]408 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]409 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
410 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
411 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
412 other characters in their names can be surrounded with quotes. Special
413 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
414 ASCII code for the character in hexadecimal. In this way, any character
415 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]416
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]417 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]418 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]419
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]420 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]421 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]422</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]423
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]424<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]425 don't need to worry about name clashes with reserved words, and the set of
426 reserved words may be expanded in the future without penalty. Additionally,
427 unnamed identifiers allow a compiler to quickly come up with a temporary
428 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]429
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]430<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]431 languages. There are keywords for different opcodes
432 ('<tt><a href="#i_add">add</a></tt>',
433 '<tt><a href="#i_bitcast">bitcast</a></tt>',
434 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
435 ('<tt><a href="#t_void">void</a></tt>',
436 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
437 reserved words cannot conflict with variable names, because none of them
438 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]439
440<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]441 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]443<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]445<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]446%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]447</pre>
448
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]449<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]450
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]451<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]452%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]453</pre>
454
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]455<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]457<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]458%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
459%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]460%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]461</pre>
462
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]463<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
464 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]466<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]468 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]469
470 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]471 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]472
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]473 <li>Unnamed temporaries are numbered sequentially</li>
474</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]475
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]476<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]477 demonstrating instructions, we will follow an instruction with a comment that
478 defines the type and name of value produced. Comments are shown in italic
479 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]480
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]481</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]482
483<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]484<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]485<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]486<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]487<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]488<h3>
489 <a name="modulestructure">Module Structure</a>
490</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]492<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]493
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]494<p>LLVM programs are composed of "Module"s, each of which is a translation unit
495 of the input programs. Each module consists of functions, global variables,
496 and symbol table entries. Modules may be combined together with the LLVM
497 linker, which merges function (and global variable) definitions, resolves
498 forward declarations, and merges symbol table entries. Here is an example of
499 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]500
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]501<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]502<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]503<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]504
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]505<i>; External declaration of the puts function</i>&nbsp;
506<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]507
508<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]509define i32 @main() { <i>; i32()* </i>&nbsp;
510 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
511 %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]512
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]513 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
514 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
515 <a href="#i_ret">ret</a> i32 0&nbsp;
516}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]517
518<i>; Named metadata</i>
519!1 = metadata !{i32 41}
520!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]521</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]522
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523<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]524 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]525 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]526 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
527 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]528
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]529<p>In general, a module is made up of a list of global values, where both
530 functions and global variables are global values. Global values are
531 represented by a pointer to a memory location (in this case, a pointer to an
532 array of char, and a pointer to a function), and have one of the
533 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]534
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]535</div>
536
537<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]538<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]539 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]540</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]541
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]542<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]543
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]544<p>All Global Variables and Functions have one of the following types of
545 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]546
547<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]549 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
550 by objects in the current module. In particular, linking code into a
551 module with an private global value may cause the private to be renamed as
552 necessary to avoid collisions. Because the symbol is private to the
553 module, all references can be updated. This doesn't show up in any symbol
554 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]555
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]556 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]557 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
558 assembler and evaluated by the linker. Unlike normal strong symbols, they
559 are removed by the linker from the final linked image (executable or
560 dynamic library).</dd>
561
562 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
563 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
564 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
565 linker. The symbols are removed by the linker from the final linked image
566 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]567
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]568 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
569 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
570 of the object is not taken. For instance, functions that had an inline
571 definition, but the compiler decided not to inline it. Note,
572 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
573 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
574 visibility. The symbols are removed by the linker from the final linked
575 image (executable or dynamic library).</dd>
576
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]577 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]578 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]579 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
580 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]581
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]582 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]583 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]584 into the object file corresponding to the LLVM module. They exist to
585 allow inlining and other optimizations to take place given knowledge of
586 the definition of the global, which is known to be somewhere outside the
587 module. Globals with <tt>available_externally</tt> linkage are allowed to
588 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
589 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]590
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]591 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]592 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]593 the same name when linkage occurs. This can be used to implement
594 some forms of inline functions, templates, or other code which must be
595 generated in each translation unit that uses it, but where the body may
596 be overridden with a more definitive definition later. Unreferenced
597 <tt>linkonce</tt> globals are allowed to be discarded. Note that
598 <tt>linkonce</tt> linkage does not actually allow the optimizer to
599 inline the body of this function into callers because it doesn't know if
600 this definition of the function is the definitive definition within the
601 program or whether it will be overridden by a stronger definition.
602 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
603 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]604
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]605 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]606 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
607 <tt>linkonce</tt> linkage, except that unreferenced globals with
608 <tt>weak</tt> linkage may not be discarded. This is used for globals that
609 are declared "weak" in C source code.</dd>
610
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]611 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]612 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
613 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
614 global scope.
615 Symbols with "<tt>common</tt>" linkage are merged in the same way as
616 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]617 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]618 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]619 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
620 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]621
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]622
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]623 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]624 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]625 pointer to array type. When two global variables with appending linkage
626 are linked together, the two global arrays are appended together. This is
627 the LLVM, typesafe, equivalent of having the system linker append together
628 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]629
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]630 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]631 <dd>The semantics of this linkage follow the ELF object file model: the symbol
632 is weak until linked, if not linked, the symbol becomes null instead of
633 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]634
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]635 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
636 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]637 <dd>Some languages allow differing globals to be merged, such as two functions
638 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]639 that only equivalent globals are ever merged (the "one definition rule"
640 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]641 and <tt>weak_odr</tt> linkage types to indicate that the global will only
642 be merged with equivalent globals. These linkage types are otherwise the
643 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]644
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]645 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]646 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]647 visible, meaning that it participates in linkage and can be used to
648 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]649</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]650
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]651<p>The next two types of linkage are targeted for Microsoft Windows platform
652 only. They are designed to support importing (exporting) symbols from (to)
653 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]654
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]655<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]656 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]657 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]658 or variable via a global pointer to a pointer that is set up by the DLL
659 exporting the symbol. On Microsoft Windows targets, the pointer name is
660 formed by combining <code>__imp_</code> and the function or variable
661 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]662
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]663 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]664 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]665 pointer to a pointer in a DLL, so that it can be referenced with the
666 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
667 name is formed by combining <code>__imp_</code> and the function or
668 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]669</dl>
670
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]671<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
672 another module defined a "<tt>.LC0</tt>" variable and was linked with this
673 one, one of the two would be renamed, preventing a collision. Since
674 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
675 declarations), they are accessible outside of the current module.</p>
676
677<p>It is illegal for a function <i>declaration</i> to have any linkage type
678 other than "externally visible", <tt>dllimport</tt>
679 or <tt>extern_weak</tt>.</p>
680
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]681<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]682 or <tt>weak_odr</tt> linkages.</p>
683
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]684</div>
685
686<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]687<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]688 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]689</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]690
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]691<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]692
693<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]694 and <a href="#i_invoke">invokes</a> can all have an optional calling
695 convention specified for the call. The calling convention of any pair of
696 dynamic caller/callee must match, or the behavior of the program is
697 undefined. The following calling conventions are supported by LLVM, and more
698 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]699
700<dl>
701 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]702 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]703 specified) matches the target C calling conventions. This calling
704 convention supports varargs function calls and tolerates some mismatch in
705 the declared prototype and implemented declaration of the function (as
706 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]707
708 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]709 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]710 (e.g. by passing things in registers). This calling convention allows the
711 target to use whatever tricks it wants to produce fast code for the
712 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]713 (Application Binary Interface).
714 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]715 when this or the GHC convention is used.</a> This calling convention
716 does not support varargs and requires the prototype of all callees to
717 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]718
719 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]720 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]721 as possible under the assumption that the call is not commonly executed.
722 As such, these calls often preserve all registers so that the call does
723 not break any live ranges in the caller side. This calling convention
724 does not support varargs and requires the prototype of all callees to
725 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]726
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]727 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
728 <dd>This calling convention has been implemented specifically for use by the
729 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
730 It passes everything in registers, going to extremes to achieve this by
731 disabling callee save registers. This calling convention should not be
732 used lightly but only for specific situations such as an alternative to
733 the <em>register pinning</em> performance technique often used when
734 implementing functional programming languages.At the moment only X86
735 supports this convention and it has the following limitations:
736 <ul>
737 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
738 floating point types are supported.</li>
739 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
740 6 floating point parameters.</li>
741 </ul>
742 This calling convention supports
743 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
744 requires both the caller and callee are using it.
745 </dd>
746
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]747 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]748 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]749 target-specific calling conventions to be used. Target specific calling
750 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]751</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]752
753<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]754 support Pascal conventions or any other well-known target-independent
755 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]756
757</div>
758
759<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]760<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]761 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]762</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]764<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]765
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]766<p>All Global Variables and Functions have one of the following visibility
767 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]768
769<dl>
770 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]771 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]772 that the declaration is visible to other modules and, in shared libraries,
773 means that the declared entity may be overridden. On Darwin, default
774 visibility means that the declaration is visible to other modules. Default
775 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]776
777 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]778 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]779 object if they are in the same shared object. Usually, hidden visibility
780 indicates that the symbol will not be placed into the dynamic symbol
781 table, so no other module (executable or shared library) can reference it
782 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]783
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]784 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]785 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]786 the dynamic symbol table, but that references within the defining module
787 will bind to the local symbol. That is, the symbol cannot be overridden by
788 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]789</dl>
790
791</div>
792
793<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]794<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]795 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]796</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]797
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]798<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]799
800<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]801 it easier to read the IR and make the IR more condensed (particularly when
802 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]803
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]804<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]805%mytype = type { %mytype*, i32 }
806</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]807
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]808<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]809 "<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]810 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]811
812<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]813 and that you can therefore specify multiple names for the same type. This
814 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
815 uses structural typing, the name is not part of the type. When printing out
816 LLVM IR, the printer will pick <em>one name</em> to render all types of a
817 particular shape. This means that if you have code where two different
818 source types end up having the same LLVM type, that the dumper will sometimes
819 print the "wrong" or unexpected type. This is an important design point and
820 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]821
822</div>
823
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]824<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]825<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]826 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]827</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]828
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]829<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]830
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]831<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]832 instead of run-time. Global variables may optionally be initialized, may
833 have an explicit section to be placed in, and may have an optional explicit
834 alignment specified. A variable may be defined as "thread_local", which
835 means that it will not be shared by threads (each thread will have a
836 separated copy of the variable). A variable may be defined as a global
837 "constant," which indicates that the contents of the variable
838 will <b>never</b> be modified (enabling better optimization, allowing the
839 global data to be placed in the read-only section of an executable, etc).
840 Note that variables that need runtime initialization cannot be marked
841 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]842
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]843<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
844 constant, even if the final definition of the global is not. This capability
845 can be used to enable slightly better optimization of the program, but
846 requires the language definition to guarantee that optimizations based on the
847 'constantness' are valid for the translation units that do not include the
848 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]849
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]850<p>As SSA values, global variables define pointer values that are in scope
851 (i.e. they dominate) all basic blocks in the program. Global variables
852 always define a pointer to their "content" type because they describe a
853 region of memory, and all memory objects in LLVM are accessed through
854 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]855
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]856<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
857 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]858 like this can be merged with other constants if they have the same
859 initializer. Note that a constant with significant address <em>can</em>
860 be merged with a <tt>unnamed_addr</tt> constant, the result being a
861 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]862
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]863<p>A global variable may be declared to reside in a target-specific numbered
864 address space. For targets that support them, address spaces may affect how
865 optimizations are performed and/or what target instructions are used to
866 access the variable. The default address space is zero. The address space
867 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]868
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]869<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]870 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]871
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]872<p>An explicit alignment may be specified for a global, which must be a power
873 of 2. If not present, or if the alignment is set to zero, the alignment of
874 the global is set by the target to whatever it feels convenient. If an
875 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]876 alignment. Targets and optimizers are not allowed to over-align the global
877 if the global has an assigned section. In this case, the extra alignment
878 could be observable: for example, code could assume that the globals are
879 densely packed in their section and try to iterate over them as an array,
880 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]881
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]882<p>For example, the following defines a global in a numbered address space with
883 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]884
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]885<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]886@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]887</pre>
888
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]889</div>
890
891
892<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]893<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]894 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]895</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]896
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]897<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]898
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]899<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]900 optional <a href="#linkage">linkage type</a>, an optional
901 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]902 <a href="#callingconv">calling convention</a>,
903 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]904 <a href="#paramattrs">parameter attribute</a> for the return type, a function
905 name, a (possibly empty) argument list (each with optional
906 <a href="#paramattrs">parameter attributes</a>), optional
907 <a href="#fnattrs">function attributes</a>, an optional section, an optional
908 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
909 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]910
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]911<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
912 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]913 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]914 <a href="#callingconv">calling convention</a>,
915 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]916 <a href="#paramattrs">parameter attribute</a> for the return type, a function
917 name, a possibly empty list of arguments, an optional alignment, and an
918 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]919
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]920<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]921 (Control Flow Graph) for the function. Each basic block may optionally start
922 with a label (giving the basic block a symbol table entry), contains a list
923 of instructions, and ends with a <a href="#terminators">terminator</a>
924 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]925
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]926<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]927 executed on entrance to the function, and it is not allowed to have
928 predecessor basic blocks (i.e. there can not be any branches to the entry
929 block of a function). Because the block can have no predecessors, it also
930 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]931
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]932<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]933 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]934
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]935<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]936 the alignment is set to zero, the alignment of the function is set by the
937 target to whatever it feels convenient. If an explicit alignment is
938 specified, the function is forced to have at least that much alignment. All
939 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]940
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]941<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
942 be significant and two identical functions can be merged</p>.
943
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]944<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]945<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]946define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]947 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
948 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
949 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
950 [<a href="#gc">gc</a>] { ... }
951</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]952
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]953</div>
954
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]955<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]956<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]957 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]958</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]959
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]960<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]961
962<p>Aliases act as "second name" for the aliasee value (which can be either
963 function, global variable, another alias or bitcast of global value). Aliases
964 may have an optional <a href="#linkage">linkage type</a>, and an
965 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]966
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]967<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]968<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]969@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]970</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]971
972</div>
973
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]974<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]975<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]976 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]977</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]978
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]979<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]980
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]981<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]982 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]983 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]984
985<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]986<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]987; Some unnamed metadata nodes, which are referenced by the named metadata.
988!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]989!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]990!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]991; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]992!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]993</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]994
995</div>
996
997<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]998<h3>
999 <a name="paramattrs">Parameter Attributes</a>
1000</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1001
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1002<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1003
1004<p>The return type and each parameter of a function type may have a set of
1005 <i>parameter attributes</i> associated with them. Parameter attributes are
1006 used to communicate additional information about the result or parameters of
1007 a function. Parameter attributes are considered to be part of the function,
1008 not of the function type, so functions with different parameter attributes
1009 can have the same function type.</p>
1010
1011<p>Parameter attributes are simple keywords that follow the type specified. If
1012 multiple parameter attributes are needed, they are space separated. For
1013 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1014
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1015<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1016declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1017declare i32 @atoi(i8 zeroext)
1018declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1019</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1020
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1021<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1022 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1023
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1024<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1025
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1026<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1027 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1028 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1029 should be zero-extended to the extent required by the target's ABI (which
1030 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1031 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1032
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1033 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1034 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1035 should be sign-extended to the extent required by the target's ABI (which
1036 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1037 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1038
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1039 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1040 <dd>This indicates that this parameter or return value should be treated in a
1041 special target-dependent fashion during while emitting code for a function
1042 call or return (usually, by putting it in a register as opposed to memory,
1043 though some targets use it to distinguish between two different kinds of
1044 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1045
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1046 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1047 <dd><p>This indicates that the pointer parameter should really be passed by
1048 value to the function. The attribute implies that a hidden copy of the
1049 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1050 is made between the caller and the callee, so the callee is unable to
1051 modify the value in the callee. This attribute is only valid on LLVM
1052 pointer arguments. It is generally used to pass structs and arrays by
1053 value, but is also valid on pointers to scalars. The copy is considered
1054 to belong to the caller not the callee (for example,
1055 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1056 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1057 values.</p>
1058
1059 <p>The byval attribute also supports specifying an alignment with
1060 the align attribute. It indicates the alignment of the stack slot to
1061 form and the known alignment of the pointer specified to the call site. If
1062 the alignment is not specified, then the code generator makes a
1063 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1064
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1065 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1066 <dd>This indicates that the pointer parameter specifies the address of a
1067 structure that is the return value of the function in the source program.
1068 This pointer must be guaranteed by the caller to be valid: loads and
1069 stores to the structure may be assumed by the callee to not to trap. This
1070 may only be applied to the first parameter. This is not a valid attribute
1071 for return values. </dd>
1072
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1073 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1074 <dd>This indicates that pointer values
1075 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1076 value do not alias pointer values which are not <i>based</i> on it,
1077 ignoring certain "irrelevant" dependencies.
1078 For a call to the parent function, dependencies between memory
1079 references from before or after the call and from those during the call
1080 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1081 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1082 The caller shares the responsibility with the callee for ensuring that
1083 these requirements are met.
1084 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1085 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1086<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1087 Note that this definition of <tt>noalias</tt> is intentionally
1088 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1089 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1090<br>
1091 For function return values, C99's <tt>restrict</tt> is not meaningful,
1092 while LLVM's <tt>noalias</tt> is.
1093 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1094
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1095 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1096 <dd>This indicates that the callee does not make any copies of the pointer
1097 that outlive the callee itself. This is not a valid attribute for return
1098 values.</dd>
1099
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1100 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1101 <dd>This indicates that the pointer parameter can be excised using the
1102 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1103 attribute for return values.</dd>
1104</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1105
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1106</div>
1107
1108<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1109<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1110 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1111</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1112
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1113<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1114
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1115<p>Each function may specify a garbage collector name, which is simply a
1116 string:</p>
1117
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1118<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1119define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1120</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1121
1122<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1123 collector which will cause the compiler to alter its output in order to
1124 support the named garbage collection algorithm.</p>
1125
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1126</div>
1127
1128<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1129<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1130 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1131</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1132
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1133<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1134
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1135<p>Function attributes are set to communicate additional information about a
1136 function. Function attributes are considered to be part of the function, not
1137 of the function type, so functions with different parameter attributes can
1138 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1139
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1140<p>Function attributes are simple keywords that follow the type specified. If
1141 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1142
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1143<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1144define void @f() noinline { ... }
1145define void @f() alwaysinline { ... }
1146define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1147define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1148</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1149
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1150<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1151 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1152 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1153 the backend should forcibly align the stack pointer. Specify the
1154 desired alignment, which must be a power of two, in parentheses.
1155
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1156 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1157 <dd>This attribute indicates that the inliner should attempt to inline this
1158 function into callers whenever possible, ignoring any active inlining size
1159 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1160
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1161 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1162 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1163 meaning the function can be patched and/or hooked even while it is
1164 loaded into memory. On x86, the function prologue will be preceded
1165 by six bytes of padding and will begin with a two-byte instruction.
1166 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1167 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1168
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1169 <dt><tt><b>nonlazybind</b></tt></dt>
1170 <dd>This attribute suppresses lazy symbol binding for the function. This
1171 may make calls to the function faster, at the cost of extra program
1172 startup time if the function is not called during program startup.</dd>
1173
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1174 <dt><tt><b>inlinehint</b></tt></dt>
1175 <dd>This attribute indicates that the source code contained a hint that inlining
1176 this function is desirable (such as the "inline" keyword in C/C++). It
1177 is just a hint; it imposes no requirements on the inliner.</dd>
1178
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1179 <dt><tt><b>naked</b></tt></dt>
1180 <dd>This attribute disables prologue / epilogue emission for the function.
1181 This can have very system-specific consequences.</dd>
1182
1183 <dt><tt><b>noimplicitfloat</b></tt></dt>
1184 <dd>This attributes disables implicit floating point instructions.</dd>
1185
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1186 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1187 <dd>This attribute indicates that the inliner should never inline this
1188 function in any situation. This attribute may not be used together with
1189 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1190
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1191 <dt><tt><b>noredzone</b></tt></dt>
1192 <dd>This attribute indicates that the code generator should not use a red
1193 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1194
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1195 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1196 <dd>This function attribute indicates that the function never returns
1197 normally. This produces undefined behavior at runtime if the function
1198 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1199
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1200 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1201 <dd>This function attribute indicates that the function never returns with an
1202 unwind or exceptional control flow. If the function does unwind, its
1203 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1204
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1205 <dt><tt><b>optsize</b></tt></dt>
1206 <dd>This attribute suggests that optimization passes and code generator passes
1207 make choices that keep the code size of this function low, and otherwise
1208 do optimizations specifically to reduce code size.</dd>
1209
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1210 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1211 <dd>This attribute indicates that the function computes its result (or decides
1212 to unwind an exception) based strictly on its arguments, without
1213 dereferencing any pointer arguments or otherwise accessing any mutable
1214 state (e.g. memory, control registers, etc) visible to caller functions.
1215 It does not write through any pointer arguments
1216 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1217 changes any state visible to callers. This means that it cannot unwind
1218 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1219 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1220
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1221 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1222 <dd>This attribute indicates that the function does not write through any
1223 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1224 arguments) or otherwise modify any state (e.g. memory, control registers,
1225 etc) visible to caller functions. It may dereference pointer arguments
1226 and read state that may be set in the caller. A readonly function always
1227 returns the same value (or unwinds an exception identically) when called
1228 with the same set of arguments and global state. It cannot unwind an
1229 exception by calling the <tt>C++</tt> exception throwing methods, but may
1230 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1231
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1232 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1233 <dd>This attribute indicates that the function should emit a stack smashing
1234 protector. It is in the form of a "canary"&mdash;a random value placed on
1235 the stack before the local variables that's checked upon return from the
1236 function to see if it has been overwritten. A heuristic is used to
1237 determine if a function needs stack protectors or not.<br>
1238<br>
1239 If a function that has an <tt>ssp</tt> attribute is inlined into a
1240 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1241 function will have an <tt>ssp</tt> attribute.</dd>
1242
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1243 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1244 <dd>This attribute indicates that the function should <em>always</em> emit a
1245 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1246 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1247<br>
1248 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1249 function that doesn't have an <tt>sspreq</tt> attribute or which has
1250 an <tt>ssp</tt> attribute, then the resulting function will have
1251 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindola163d6752011-07-25 15:27:59 +0000[diff] [blame]1252
1253 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1254 <dd>This attribute indicates that the ABI being targeted requires that
1255 an unwind table entry be produce for this function even if we can
1256 show that no exceptions passes by it. This is normally the case for
1257 the ELF x86-64 abi, but it can be disabled for some compilation
1258 units.</dd>
1259
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1260</dl>
1261
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1262</div>
1263
1264<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1265<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1266 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1267</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1268
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1269<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1270
1271<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1272 the GCC "file scope inline asm" blocks. These blocks are internally
1273 concatenated by LLVM and treated as a single unit, but may be separated in
1274 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1275
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1276<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1277module asm "inline asm code goes here"
1278module asm "more can go here"
1279</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1280
1281<p>The strings can contain any character by escaping non-printable characters.
1282 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]1283 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1284
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1285<p>The inline asm code is simply printed to the machine code .s file when
1286 assembly code is generated.</p>
1287
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1288</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1289
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1290<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1291<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1292 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1293</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1294
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1295<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1296
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1297<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1298 data is to be laid out in memory. The syntax for the data layout is
1299 simply:</p>
1300
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1301<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1302target datalayout = "<i>layout specification</i>"
1303</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1304
1305<p>The <i>layout specification</i> consists of a list of specifications
1306 separated by the minus sign character ('-'). Each specification starts with
1307 a letter and may include other information after the letter to define some
1308 aspect of the data layout. The specifications accepted are as follows:</p>
1309
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1310<dl>
1311 <dt><tt>E</tt></dt>
1312 <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]1313 bits with the most significance have the lowest address location.</dd>
1314
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1315 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1316 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1317 the bits with the least significance have the lowest address
1318 location.</dd>
1319
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1320 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1321 <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]1322 <i>preferred</i> alignments. All sizes are in bits. Specifying
1323 the <i>pref</i> alignment is optional. If omitted, the
1324 preceding <tt>:</tt> should be omitted too.</dd>
1325
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1326 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1327 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1328 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1329
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1330 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1331 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1332 <i>size</i>.</dd>
1333
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1334 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1335 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1336 <i>size</i>. Only values of <i>size</i> that are supported by the target
1337 will work. 32 (float) and 64 (double) are supported on all targets;
1338 80 or 128 (different flavors of long double) are also supported on some
1339 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1340
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1341 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1342 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1343 <i>size</i>.</dd>
1344
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1345 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1346 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1347 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1348
1349 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1350 <dd>This specifies a set of native integer widths for the target CPU
1351 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1352 "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]1353 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1354 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1355</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1356
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1357<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1358 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1359 specifications in the <tt>datalayout</tt> keyword. The default specifications
1360 are given in this list:</p>
1361
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1362<ul>
1363 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1364 <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]1365 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1366 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1367 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1368 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1369 <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]1370 alignment of 64-bits</li>
1371 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1372 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1373 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1374 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1375 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1376 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1377</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1378
1379<p>When LLVM is determining the alignment for a given type, it uses the
1380 following rules:</p>
1381
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1382<ol>
1383 <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]1384 specification is used.</li>
1385
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1386 <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]1387 smallest integer type that is larger than the bitwidth of the sought type
1388 is used. If none of the specifications are larger than the bitwidth then
1389 the the largest integer type is used. For example, given the default
1390 specifications above, the i7 type will use the alignment of i8 (next
1391 largest) while both i65 and i256 will use the alignment of i64 (largest
1392 specified).</li>
1393
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1394 <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]1395 largest vector type that is smaller than the sought vector type will be
1396 used as a fall back. This happens because &lt;128 x double&gt; can be
1397 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1398</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1399
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1400</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1401
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1402<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1403<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1404 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1405</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1406
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1407<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1408
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1409<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1410with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1411is undefined. Pointer values are associated with address ranges
1412according to the following rules:</p>
1413
1414<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1415 <li>A pointer value is associated with the addresses associated with
1416 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1417 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1418 range of the variable's storage.</li>
1419 <li>The result value of an allocation instruction is associated with
1420 the address range of the allocated storage.</li>
1421 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1422 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1423 <li>An integer constant other than zero or a pointer value returned
1424 from a function not defined within LLVM may be associated with address
1425 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1426 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1427 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1428</ul>
1429
1430<p>A pointer value is <i>based</i> on another pointer value according
1431 to the following rules:</p>
1432
1433<ul>
1434 <li>A pointer value formed from a
1435 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1436 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1437 <li>The result value of a
1438 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1439 of the <tt>bitcast</tt>.</li>
1440 <li>A pointer value formed by an
1441 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1442 pointer values that contribute (directly or indirectly) to the
1443 computation of the pointer's value.</li>
1444 <li>The "<i>based</i> on" relationship is transitive.</li>
1445</ul>
1446
1447<p>Note that this definition of <i>"based"</i> is intentionally
1448 similar to the definition of <i>"based"</i> in C99, though it is
1449 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1450
1451<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1452<tt><a href="#i_load">load</a></tt> merely indicates the size and
1453alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1454interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1455<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1456and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1457
1458<p>Consequently, type-based alias analysis, aka TBAA, aka
1459<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1460LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1461additional information which specialized optimization passes may use
1462to implement type-based alias analysis.</p>
1463
1464</div>
1465
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1466<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1467<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1468 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1469</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1470
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1471<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1472
1473<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1474href="#i_store"><tt>store</tt></a>s, and <a
1475href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1476The optimizers must not change the number of volatile operations or change their
1477order of execution relative to other volatile operations. The optimizers
1478<i>may</i> change the order of volatile operations relative to non-volatile
1479operations. This is not Java's "volatile" and has no cross-thread
1480synchronization behavior.</p>
1481
1482</div>
1483
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1484<!-- ======================================================================= -->
1485<h3>
1486 <a name="memmodel">Memory Model for Concurrent Operations</a>
1487</h3>
1488
1489<div>
1490
1491<p>The LLVM IR does not define any way to start parallel threads of execution
1492or to register signal handlers. Nonetheless, there are platform-specific
1493ways to create them, and we define LLVM IR's behavior in their presence. This
1494model is inspired by the C++0x memory model.</p>
1495
1496<p>We define a <i>happens-before</i> partial order as the least partial order
1497that</p>
1498<ul>
1499 <li>Is a superset of single-thread program order, and</li>
1500 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1501 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1502 by platform-specific techniques, like pthread locks, thread
1503 creation, thread joining, etc., and by the atomic operations described
1504 in the <a href="#int_atomics">Atomic intrinsics</a> section.</li>
1505</ul>
1506
1507<p>Note that program order does not introduce <i>happens-before</i> edges
1508between a thread and signals executing inside that thread.</p>
1509
1510<p>Every (defined) read operation (load instructions, memcpy, atomic
1511loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1512(defined) write operations (store instructions, atomic
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1513stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1514initialized globals are considered to have a write of the initializer which is
1515atomic and happens before any other read or write of the memory in question.
1516For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1517any write to the same byte, except:</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1518
1519<ul>
1520 <li>If <var>write<sub>1</sub></var> happens before
1521 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1522 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1523 does not see <var>write<sub>1</sub></var>.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1524 <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]1525 then <var>R<sub>byte</sub></var> does not see
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1526 <var>write<sub>3</sub></var>.
1527</ul>
1528
1529<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1530<ul>
1531 <li>If there is no write to the same byte that happens before
1532 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1533 <tt>undef</tt> for that byte.
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1534 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1535 <var>R<sub>byte</sub></var> returns the value written by that
1536 write.</li>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1537 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1538 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
1539 values written. See the <a href="#int_atomics">Atomic intrinsics</a>
1540 section for additional guarantees on how the choice is made.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1541 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1542</ul>
1543
1544<p><var>R</var> returns the value composed of the series of bytes it read.
1545This implies that some bytes within the value may be <tt>undef</tt>
1546<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1547defines the semantics of the operation; it doesn't mean that targets will
1548emit more than one instruction to read the series of bytes.</p>
1549
1550<p>Note that in cases where none of the atomic intrinsics are used, this model
1551places only one restriction on IR transformations on top of what is required
1552for single-threaded execution: introducing a store to a byte which might not
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1553otherwise be stored to can introduce undefined behavior. (Specifically, in
1554the case where another thread might write to and read from an address,
1555introducing a store can change a load that may see exactly one write into
1556a load that may see multiple writes.)</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1557
1558<!-- FIXME: This model assumes all targets where concurrency is relevant have
1559a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1560none of the backends currently in the tree fall into this category; however,
1561there might be targets which care. If there are, we want a paragraph
1562like the following:
1563
1564Targets may specify that stores narrower than a certain width are not
1565available; on such a target, for the purposes of this model, treat any
1566non-atomic write with an alignment or width less than the minimum width
1567as if it writes to the relevant surrounding bytes.
1568-->
1569
1570</div>
1571
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1572</div>
1573
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1574<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1575<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1576<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1577
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1578<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1579
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1580<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1581 intermediate representation. Being typed enables a number of optimizations
1582 to be performed on the intermediate representation directly, without having
1583 to do extra analyses on the side before the transformation. A strong type
1584 system makes it easier to read the generated code and enables novel analyses
1585 and transformations that are not feasible to perform on normal three address
1586 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1587
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1588<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1589<h3>
1590 <a name="t_classifications">Type Classifications</a>
1591</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1592
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1593<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1594
1595<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1596
1597<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1598 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1599 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1600 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1601 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1602 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1603 </tr>
1604 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1605 <td><a href="#t_floating">floating point</a></td>
1606 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1607 </tr>
1608 <tr>
1609 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1610 <td><a href="#t_integer">integer</a>,
1611 <a href="#t_floating">floating point</a>,
1612 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1613 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1614 <a href="#t_struct">structure</a>,
1615 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1616 <a href="#t_label">label</a>,
1617 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1618 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1619 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1620 <tr>
1621 <td><a href="#t_primitive">primitive</a></td>
1622 <td><a href="#t_label">label</a>,
1623 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1624 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1625 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1626 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1627 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1628 </tr>
1629 <tr>
1630 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1631 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1632 <a href="#t_function">function</a>,
1633 <a href="#t_pointer">pointer</a>,
1634 <a href="#t_struct">structure</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1635 <a href="#t_vector">vector</a>,
1636 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1637 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1638 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1639 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1640</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1641
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1642<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1643 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1644 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1645
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1646</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1647
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1648<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1649<h3>
1650 <a name="t_primitive">Primitive Types</a>
1651</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1652
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1653<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1654
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1655<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1656 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1657
1658<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1659<h4>
1660 <a name="t_integer">Integer Type</a>
1661</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1662
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1663<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1664
1665<h5>Overview:</h5>
1666<p>The integer type is a very simple type that simply specifies an arbitrary
1667 bit width for the integer type desired. Any bit width from 1 bit to
1668 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1669
1670<h5>Syntax:</h5>
1671<pre>
1672 iN
1673</pre>
1674
1675<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1676 value.</p>
1677
1678<h5>Examples:</h5>
1679<table class="layout">
1680 <tr class="layout">
1681 <td class="left"><tt>i1</tt></td>
1682 <td class="left">a single-bit integer.</td>
1683 </tr>
1684 <tr class="layout">
1685 <td class="left"><tt>i32</tt></td>
1686 <td class="left">a 32-bit integer.</td>
1687 </tr>
1688 <tr class="layout">
1689 <td class="left"><tt>i1942652</tt></td>
1690 <td class="left">a really big integer of over 1 million bits.</td>
1691 </tr>
1692</table>
1693
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1694</div>
1695
1696<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1697<h4>
1698 <a name="t_floating">Floating Point Types</a>
1699</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1700
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1701<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1702
1703<table>
1704 <tbody>
1705 <tr><th>Type</th><th>Description</th></tr>
1706 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1707 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1708 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1709 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1710 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1711 </tbody>
1712</table>
1713
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1714</div>
1715
1716<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1717<h4>
1718 <a name="t_x86mmx">X86mmx Type</a>
1719</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1720
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1721<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1722
1723<h5>Overview:</h5>
1724<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>
1725
1726<h5>Syntax:</h5>
1727<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1728 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1729</pre>
1730
1731</div>
1732
1733<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1734<h4>
1735 <a name="t_void">Void Type</a>
1736</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1737
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1738<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1739
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1740<h5>Overview:</h5>
1741<p>The void type does not represent any value and has no size.</p>
1742
1743<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1744<pre>
1745 void
1746</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1747
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1748</div>
1749
1750<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1751<h4>
1752 <a name="t_label">Label Type</a>
1753</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1754
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1755<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1756
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1757<h5>Overview:</h5>
1758<p>The label type represents code labels.</p>
1759
1760<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1761<pre>
1762 label
1763</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1764
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1765</div>
1766
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1767<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1768<h4>
1769 <a name="t_metadata">Metadata Type</a>
1770</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1771
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1772<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1773
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1774<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1775<p>The metadata type represents embedded metadata. No derived types may be
1776 created from metadata except for <a href="#t_function">function</a>
1777 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1778
1779<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1780<pre>
1781 metadata
1782</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1783
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1784</div>
1785
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1786</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1787
1788<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1789<h3>
1790 <a name="t_derived">Derived Types</a>
1791</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1792
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1793<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1794
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1795<p>The real power in LLVM comes from the derived types in the system. This is
1796 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1797 useful types. Each of these types contain one or more element types which
1798 may be a primitive type, or another derived type. For example, it is
1799 possible to have a two dimensional array, using an array as the element type
1800 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1801
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1802</div>
1803
1804
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1805<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1806<h4>
1807 <a name="t_aggregate">Aggregate Types</a>
1808</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1809
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1810<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1811
1812<p>Aggregate Types are a subset of derived types that can contain multiple
1813 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1814 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1815 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1816
1817</div>
1818
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1819<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1820<h4>
1821 <a name="t_array">Array Type</a>
1822</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1823
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1824<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1825
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1826<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1827<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1828 sequentially in memory. The array type requires a size (number of elements)
1829 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1830
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1831<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1832<pre>
1833 [&lt;# elements&gt; x &lt;elementtype&gt;]
1834</pre>
1835
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1836<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1837 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1838
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1839<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1840<table class="layout">
1841 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1842 <td class="left"><tt>[40 x i32]</tt></td>
1843 <td class="left">Array of 40 32-bit integer values.</td>
1844 </tr>
1845 <tr class="layout">
1846 <td class="left"><tt>[41 x i32]</tt></td>
1847 <td class="left">Array of 41 32-bit integer values.</td>
1848 </tr>
1849 <tr class="layout">
1850 <td class="left"><tt>[4 x i8]</tt></td>
1851 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1852 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1853</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1854<p>Here are some examples of multidimensional arrays:</p>
1855<table class="layout">
1856 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1857 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1858 <td class="left">3x4 array of 32-bit integer values.</td>
1859 </tr>
1860 <tr class="layout">
1861 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1862 <td class="left">12x10 array of single precision floating point values.</td>
1863 </tr>
1864 <tr class="layout">
1865 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1866 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1867 </tr>
1868</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1869
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1870<p>There is no restriction on indexing beyond the end of the array implied by
1871 a static type (though there are restrictions on indexing beyond the bounds
1872 of an allocated object in some cases). This means that single-dimension
1873 'variable sized array' addressing can be implemented in LLVM with a zero
1874 length array type. An implementation of 'pascal style arrays' in LLVM could
1875 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1876
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1877</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1878
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1879<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1880<h4>
1881 <a name="t_function">Function Type</a>
1882</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1883
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1884<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1885
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1886<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1887<p>The function type can be thought of as a function signature. It consists of
1888 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]1889 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1890
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1891<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1892<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1893 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1894</pre>
1895
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1896<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]1897 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1898 which indicates that the function takes a variable number of arguments.
1899 Variable argument functions can access their arguments with
1900 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1901 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1902 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1903
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1904<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1905<table class="layout">
1906 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1907 <td class="left"><tt>i32 (i32)</tt></td>
1908 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1909 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1910 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1911 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1912 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1913 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1914 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1915 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1916 </td>
1917 </tr><tr class="layout">
1918 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1919 <td class="left">A vararg function that takes at least one
1920 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1921 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1922 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1923 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1924 </tr><tr class="layout">
1925 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1926 <td class="left">A function taking an <tt>i32</tt>, returning a
1927 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1928 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1929 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1930</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1931
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1932</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1933
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1934<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1935<h4>
1936 <a name="t_struct">Structure Type</a>
1937</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1938
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1939<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1940
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1941<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1942<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1943 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]1944
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1945<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1946 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1947 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1948 Structures in registers are accessed using the
1949 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1950 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1951
1952<p>Structures may optionally be "packed" structures, which indicate that the
1953 alignment of the struct is one byte, and that there is no padding between
1954 the elements. In non-packed structs, padding between field types is defined
1955 by the target data string to match the underlying processor.</p>
1956
1957<p>Structures can either be "anonymous" or "named". An anonymous structure is
1958 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
1959 are always defined at the top level with a name. Anonmyous types are uniqued
1960 by their contents and can never be recursive since there is no way to write
1961 one. Named types can be recursive.
1962</p>
1963
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1964<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1965<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1966 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
1967 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1968</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1969
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1970<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1971<table class="layout">
1972 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1973 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1974 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1975 </tr>
1976 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1977 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1978 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1979 second element is a <a href="#t_pointer">pointer</a> to a
1980 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1981 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1982 </tr>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1983 <tr class="layout">
1984 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
1985 <td class="left">A packed struct known to be 5 bytes in size.</td>
1986 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1987</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1988
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1989</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1990
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1991<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1992<h4>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]1993 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1994</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1995
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1996<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1997
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1998<h5>Overview:</h5>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]1999<p>Opaque structure types are used to represent named structure types that do
2000 not have a body specified. This corresponds (for example) to the C notion of
2001 a forward declared structure.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2002
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2003<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2004<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2005 %X = type opaque
2006 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2007</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2008
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2009<h5>Examples:</h5>
2010<table class="layout">
2011 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2012 <td class="left"><tt>opaque</tt></td>
2013 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2014 </tr>
2015</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2016
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2017</div>
2018
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2019
2020
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2021<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2022<h4>
2023 <a name="t_pointer">Pointer Type</a>
2024</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2025
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2026<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2027
2028<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]2029<p>The pointer type is used to specify memory locations.
2030 Pointers are commonly used to reference objects in memory.</p>
2031
2032<p>Pointer types may have an optional address space attribute defining the
2033 numbered address space where the pointed-to object resides. The default
2034 address space is number zero. The semantics of non-zero address
2035 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2036
2037<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2038 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2039
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2040<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2041<pre>
2042 &lt;type&gt; *
2043</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2044
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2045<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2046<table class="layout">
2047 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2048 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2049 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2050 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2051 </tr>
2052 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]2053 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2054 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2055 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2056 <tt>i32</tt>.</td>
2057 </tr>
2058 <tr class="layout">
2059 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2060 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2061 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2062 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2063</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2064
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2065</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2066
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2067<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2068<h4>
2069 <a name="t_vector">Vector Type</a>
2070</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2071
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2072<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2073
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2074<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2075<p>A vector type is a simple derived type that represents a vector of elements.
2076 Vector types are used when multiple primitive data are operated in parallel
2077 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]2078 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2079 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2080
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2081<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2082<pre>
2083 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2084</pre>
2085
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]2086<p>The number of elements is a constant integer value larger than 0; elementtype
2087 may be any integer or floating point type. Vectors of size zero are not
2088 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2089
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2090<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2091<table class="layout">
2092 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2093 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2094 <td class="left">Vector of 4 32-bit integer values.</td>
2095 </tr>
2096 <tr class="layout">
2097 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2098 <td class="left">Vector of 8 32-bit floating-point values.</td>
2099 </tr>
2100 <tr class="layout">
2101 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2102 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2103 </tr>
2104</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2105
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2106</div>
2107
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2108<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2109<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2110<!-- *********************************************************************** -->
2111
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2112<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2113
2114<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2115 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2116
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2117<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2118<h3>
2119 <a name="simpleconstants">Simple Constants</a>
2120</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2121
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2122<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2123
2124<dl>
2125 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2126 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2127 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2128
2129 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2130 <dd>Standard integers (such as '4') are constants of
2131 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2132 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2133
2134 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2135 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2136 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2137 notation (see below). The assembler requires the exact decimal value of a
2138 floating-point constant. For example, the assembler accepts 1.25 but
2139 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2140 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2141
2142 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2143 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2144 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2145</dl>
2146
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2147<p>The one non-intuitive notation for constants is the hexadecimal form of
2148 floating point constants. For example, the form '<tt>double
2149 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2150 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2151 constants are required (and the only time that they are generated by the
2152 disassembler) is when a floating point constant must be emitted but it cannot
2153 be represented as a decimal floating point number in a reasonable number of
2154 digits. For example, NaN's, infinities, and other special values are
2155 represented in their IEEE hexadecimal format so that assembly and disassembly
2156 do not cause any bits to change in the constants.</p>
2157
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2158<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2159 represented using the 16-digit form shown above (which matches the IEEE754
2160 representation for double); float values must, however, be exactly
2161 representable as IEE754 single precision. Hexadecimal format is always used
2162 for long double, and there are three forms of long double. The 80-bit format
2163 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2164 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2165 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2166 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2167 currently supported target uses this format. Long doubles will only work if
2168 they match the long double format on your target. All hexadecimal formats
2169 are big-endian (sign bit at the left).</p>
2170
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2171<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2172</div>
2173
2174<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2175<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2176<a name="aggregateconstants"></a> <!-- old anchor -->
2177<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2178</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2179
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2180<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2181
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2182<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2183 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2184
2185<dl>
2186 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2187 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2188 type definitions (a comma separated list of elements, surrounded by braces
2189 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2190 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2191 Structure constants must have <a href="#t_struct">structure type</a>, and
2192 the number and types of elements must match those specified by the
2193 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2194
2195 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2196 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2197 definitions (a comma separated list of elements, surrounded by square
2198 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2199 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2200 the number and types of elements must match those specified by the
2201 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2202
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2203 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2204 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2205 definitions (a comma separated list of elements, surrounded by
2206 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2207 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2208 have <a href="#t_vector">vector type</a>, and the number and types of
2209 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2210
2211 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2212 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2213 value to zero of <em>any</em> type, including scalar and
2214 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2215 This is often used to avoid having to print large zero initializers
2216 (e.g. for large arrays) and is always exactly equivalent to using explicit
2217 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2218
2219 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2220 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2221 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2222 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2223 be interpreted as part of the instruction stream, metadata is a place to
2224 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2225</dl>
2226
2227</div>
2228
2229<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2230<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2231 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2232</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2233
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2234<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2235
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2236<p>The addresses of <a href="#globalvars">global variables</a>
2237 and <a href="#functionstructure">functions</a> are always implicitly valid
2238 (link-time) constants. These constants are explicitly referenced when
2239 the <a href="#identifiers">identifier for the global</a> is used and always
2240 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2241 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2242
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2243<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2244@X = global i32 17
2245@Y = global i32 42
2246@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2247</pre>
2248
2249</div>
2250
2251<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2252<h3>
2253 <a name="undefvalues">Undefined Values</a>
2254</h3>
2255
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2256<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2257
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2258<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]2259 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2260 Undefined values may be of any type (other than '<tt>label</tt>'
2261 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2262
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2263<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2264 program is well defined no matter what value is used. This gives the
2265 compiler more freedom to optimize. Here are some examples of (potentially
2266 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2267
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2268
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2269<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2270 %A = add %X, undef
2271 %B = sub %X, undef
2272 %C = xor %X, undef
2273Safe:
2274 %A = undef
2275 %B = undef
2276 %C = undef
2277</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2278
2279<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]2280 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]2281
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2282<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2283 %A = or %X, undef
2284 %B = and %X, undef
2285Safe:
2286 %A = -1
2287 %B = 0
2288Unsafe:
2289 %A = undef
2290 %B = undef
2291</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2292
2293<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2294 For example, if <tt>%X</tt> has a zero bit, then the output of the
2295 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2296 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2297 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2298 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2299 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2300 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2301 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2302
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2303<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2304 %A = select undef, %X, %Y
2305 %B = select undef, 42, %Y
2306 %C = select %X, %Y, undef
2307Safe:
2308 %A = %X (or %Y)
2309 %B = 42 (or %Y)
2310 %C = %Y
2311Unsafe:
2312 %A = undef
2313 %B = undef
2314 %C = undef
2315</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2316
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2317<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2318 branch) conditions can go <em>either way</em>, but they have to come from one
2319 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2320 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2321 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2322 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2323 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2324 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2325
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2326<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2327 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2328
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2329 %B = undef
2330 %C = xor %B, %B
2331
2332 %D = undef
2333 %E = icmp lt %D, 4
2334 %F = icmp gte %D, 4
2335
2336Safe:
2337 %A = undef
2338 %B = undef
2339 %C = undef
2340 %D = undef
2341 %E = undef
2342 %F = undef
2343</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2344
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2345<p>This example points out that two '<tt>undef</tt>' operands are not
2346 necessarily the same. This can be surprising to people (and also matches C
2347 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2348 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2349 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2350 its value over its "live range". This is true because the variable doesn't
2351 actually <em>have a live range</em>. Instead, the value is logically read
2352 from arbitrary registers that happen to be around when needed, so the value
2353 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2354 need to have the same semantics or the core LLVM "replace all uses with"
2355 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2356
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2357<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2358 %A = fdiv undef, %X
2359 %B = fdiv %X, undef
2360Safe:
2361 %A = undef
2362b: unreachable
2363</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2364
2365<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2366 value</em> and <em>undefined behavior</em>. An undefined value (like
2367 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2368 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2369 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2370 defined on SNaN's. However, in the second example, we can make a more
2371 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2372 arbitrary value, we are allowed to assume that it could be zero. Since a
2373 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2374 the operation does not execute at all. This allows us to delete the divide and
2375 all code after it. Because the undefined operation "can't happen", the
2376 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2377
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2378<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2379a: store undef -> %X
2380b: store %X -> undef
2381Safe:
2382a: &lt;deleted&gt;
2383b: unreachable
2384</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2385
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2386<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2387 undefined value can be assumed to not have any effect; we can assume that the
2388 value is overwritten with bits that happen to match what was already there.
2389 However, a store <em>to</em> an undefined location could clobber arbitrary
2390 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2391
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2392</div>
2393
2394<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2395<h3>
2396 <a name="trapvalues">Trap Values</a>
2397</h3>
2398
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2399<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2400
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2401<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2402 instead of representing an unspecified bit pattern, they represent the
2403 fact that an instruction or constant expression which cannot evoke side
2404 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2405 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2406
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2407<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]2408 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2409 <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]2410
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2411<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2412
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2413<ul>
2414<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2415 their operands.</li>
2416
2417<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2418 to their dynamic predecessor basic block.</li>
2419
2420<li>Function arguments depend on the corresponding actual argument values in
2421 the dynamic callers of their functions.</li>
2422
2423<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2424 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2425 control back to them.</li>
2426
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2427<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2428 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2429 or exception-throwing call instructions that dynamically transfer control
2430 back to them.</li>
2431
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2432<li>Non-volatile loads and stores depend on the most recent stores to all of the
2433 referenced memory addresses, following the order in the IR
2434 (including loads and stores implied by intrinsics such as
2435 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2436
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2437<!-- TODO: In the case of multiple threads, this only applies if the store
2438 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2439
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2440<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2441
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2442<li>An instruction with externally visible side effects depends on the most
2443 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2444 the order in the IR. (This includes
2445 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2446
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2447<li>An instruction <i>control-depends</i> on a
2448 <a href="#terminators">terminator instruction</a>
2449 if the terminator instruction has multiple successors and the instruction
2450 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2451 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2452
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2453<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2454 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2455 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2456 successor.</li>
2457
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2458<li>Dependence is transitive.</li>
2459
2460</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2461
2462<p>Whenever a trap value is generated, all values which depend on it evaluate
2463 to trap. If they have side effects, the evoke their side effects as if each
2464 operand with a trap value were undef. If they have externally-visible side
2465 effects, the behavior is undefined.</p>
2466
2467<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2468
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2469<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2470entry:
2471 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2472 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2473 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2474 store i32 0, i32* %trap_yet_again ; undefined behavior
2475
2476 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2477 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2478
2479 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2480
2481 %narrowaddr = bitcast i32* @g to i16*
2482 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2483 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2484 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2485
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2486 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2487 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2488
2489true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2490 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2491 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2492 br label %end
2493
2494end:
2495 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2496 ; Both edges into this PHI are
2497 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2498 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2499
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2500 volatile store i32 0, i32* @g ; This would depend on the store in %true
2501 ; if %cmp is true, or the store in %entry
2502 ; otherwise, so this is undefined behavior.
2503
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2504 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2505 ; The same branch again, but this time the
2506 ; true block doesn't have side effects.
2507
2508second_true:
2509 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2510 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2511
2512second_end:
2513 volatile store i32 0, i32* @g ; This time, the instruction always depends
2514 ; on the store in %end. Also, it is
2515 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2516 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2517 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2518</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2519
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2520</div>
2521
2522<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2523<h3>
2524 <a name="blockaddress">Addresses of Basic Blocks</a>
2525</h3>
2526
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2527<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2528
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2529<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2530
2531<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2532 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2533 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2534
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2535<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2536 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2537 comparisons against null. Pointer equality tests between labels addresses
2538 results in undefined behavior &mdash; though, again, comparison against null
2539 is ok, and no label is equal to the null pointer. This may be passed around
2540 as an opaque pointer sized value as long as the bits are not inspected. This
2541 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2542 long as the original value is reconstituted before the <tt>indirectbr</tt>
2543 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2544
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2545<p>Finally, some targets may provide defined semantics when using the value as
2546 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2547
2548</div>
2549
2550
2551<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2552<h3>
2553 <a name="constantexprs">Constant Expressions</a>
2554</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2555
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2556<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2557
2558<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2559 to be used as constants. Constant expressions may be of
2560 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2561 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2562 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2563
2564<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2565 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2566 <dd>Truncate a constant to another type. The bit size of CST must be larger
2567 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2568
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2569 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2570 <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]2571 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2572
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2573 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2574 <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]2575 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2576
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2577 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2578 <dd>Truncate a floating point constant to another floating point type. The
2579 size of CST must be larger than the size of TYPE. Both types must be
2580 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2581
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2582 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2583 <dd>Floating point extend a constant to another type. The size of CST must be
2584 smaller or equal to the size of TYPE. Both types must be floating
2585 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2586
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2587 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2588 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2589 constant. TYPE must be a scalar or vector integer type. CST must be of
2590 scalar or vector floating point type. Both CST and TYPE must be scalars,
2591 or vectors of the same number of elements. If the value won't fit in the
2592 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2593
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2594 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2595 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2596 constant. TYPE must be a scalar or vector integer type. CST must be of
2597 scalar or vector floating point type. Both CST and TYPE must be scalars,
2598 or vectors of the same number of elements. If the value won't fit in the
2599 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2600
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2601 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2602 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2603 constant. TYPE must be a scalar or vector floating point type. CST must be
2604 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2605 vectors of the same number of elements. If the value won't fit in the
2606 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2607
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2608 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2609 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2610 constant. TYPE must be a scalar or vector floating point type. CST must be
2611 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2612 vectors of the same number of elements. If the value won't fit in the
2613 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2614
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2615 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2616 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2617 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2618 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2619 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2620
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2621 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2622 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2623 type. CST must be of integer type. The CST value is zero extended,
2624 truncated, or unchanged to make it fit in a pointer size. This one is
2625 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2626
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2627 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2628 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2629 are the same as those for the <a href="#i_bitcast">bitcast
2630 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2631
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2632 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2633 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2634 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2635 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2636 instruction, the index list may have zero or more indexes, which are
2637 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2638
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2639 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2640 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2641
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2642 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2643 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2644
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2645 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2646 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2647
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2648 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2649 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2650 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2651
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2652 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2653 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2654 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2655
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2656 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2657 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2658 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2659
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2660 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2661 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2662 constants. The index list is interpreted in a similar manner as indices in
2663 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2664 index value must be specified.</dd>
2665
2666 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2667 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2668 constants. The index list is interpreted in a similar manner as indices in
2669 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2670 index value must be specified.</dd>
2671
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2672 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2673 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2674 be any of the <a href="#binaryops">binary</a>
2675 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2676 on operands are the same as those for the corresponding instruction
2677 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2678</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2679
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2680</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2681
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2682</div>
2683
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2684<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2685<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2686<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2687<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2688<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2689<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2690<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2691</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2692
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2693<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2694
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2695<p>LLVM supports inline assembler expressions (as opposed
2696 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2697 a special value. This value represents the inline assembler as a string
2698 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2699 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2700 expression has side effects, and a flag indicating whether the function
2701 containing the asm needs to align its stack conservatively. An example
2702 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2703
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2704<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2705i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2706</pre>
2707
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2708<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2709 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2710 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2711
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2712<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2713%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]2714</pre>
2715
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2716<p>Inline asms with side effects not visible in the constraint list must be
2717 marked as having side effects. This is done through the use of the
2718 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2719
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2720<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2721call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2722</pre>
2723
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2724<p>In some cases inline asms will contain code that will not work unless the
2725 stack is aligned in some way, such as calls or SSE instructions on x86,
2726 yet will not contain code that does that alignment within the asm.
2727 The compiler should make conservative assumptions about what the asm might
2728 contain and should generate its usual stack alignment code in the prologue
2729 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2730
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2731<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2732call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2733</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2734
2735<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2736 first.</p>
2737
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2738<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2739 documented here. Constraints on what can be done (e.g. duplication, moving,
2740 etc need to be documented). This is probably best done by reference to
2741 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2742
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2743<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2744<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2745</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2746
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2747<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2748
2749<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2750 attached to it that contains a list of constant integers. If present, the
2751 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2752 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2753 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2754 source code that produced it. For example:</p>
2755
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2756<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2757call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2758...
2759!42 = !{ i32 1234567 }
2760</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2761
2762<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]2763 IR. If the MDNode contains multiple constants, the code generator will use
2764 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]2765
2766</div>
2767
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2768</div>
2769
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2770<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2771<h3>
2772 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2773</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2774
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2775<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2776
2777<p>LLVM IR allows metadata to be attached to instructions in the program that
2778 can convey extra information about the code to the optimizers and code
2779 generator. One example application of metadata is source-level debug
2780 information. There are two metadata primitives: strings and nodes. All
2781 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2782 preceding exclamation point ('<tt>!</tt>').</p>
2783
2784<p>A metadata string is a string surrounded by double quotes. It can contain
2785 any character by escaping non-printable characters with "\xx" where "xx" is
2786 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2787
2788<p>Metadata nodes are represented with notation similar to structure constants
2789 (a comma separated list of elements, surrounded by braces and preceded by an
2790 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2791 10}</tt>". Metadata nodes can have any values as their operand.</p>
2792
2793<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2794 metadata nodes, which can be looked up in the module symbol table. For
2795 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2796
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2797<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2798 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2799
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2800<div class="doc_code">
2801<pre>
2802call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2803</pre>
2804</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2805
2806<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2807 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2808
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2809<div class="doc_code">
2810<pre>
2811%indvar.next = add i64 %indvar, 1, !dbg !21
2812</pre>
2813</div>
2814
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2815</div>
2816
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2817</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2818
2819<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2820<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2821 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2822</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2823<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2824<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2825<p>LLVM has a number of "magic" global variables that contain data that affect
2826code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2827of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2828section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2829by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2830
2831<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2832<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2833<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2834</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2835
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2836<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2837
2838<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2839href="#linkage_appending">appending linkage</a>. This array contains a list of
2840pointers to global variables and functions which may optionally have a pointer
2841cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2842
2843<pre>
2844 @X = global i8 4
2845 @Y = global i32 123
2846
2847 @llvm.used = appending global [2 x i8*] [
2848 i8* @X,
2849 i8* bitcast (i32* @Y to i8*)
2850 ], section "llvm.metadata"
2851</pre>
2852
2853<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2854compiler, assembler, and linker are required to treat the symbol as if there is
2855a reference to the global that it cannot see. For example, if a variable has
2856internal linkage and no references other than that from the <tt>@llvm.used</tt>
2857list, it cannot be deleted. This is commonly used to represent references from
2858inline asms and other things the compiler cannot "see", and corresponds to
2859"attribute((used))" in GNU C.</p>
2860
2861<p>On some targets, the code generator must emit a directive to the assembler or
2862object file to prevent the assembler and linker from molesting the symbol.</p>
2863
2864</div>
2865
2866<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2867<h3>
2868 <a name="intg_compiler_used">
2869 The '<tt>llvm.compiler.used</tt>' Global Variable
2870 </a>
2871</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2872
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2873<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2874
2875<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2876<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2877touching the symbol. On targets that support it, this allows an intelligent
2878linker to optimize references to the symbol without being impeded as it would be
2879by <tt>@llvm.used</tt>.</p>
2880
2881<p>This is a rare construct that should only be used in rare circumstances, and
2882should not be exposed to source languages.</p>
2883
2884</div>
2885
2886<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2887<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2888<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2889</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2890
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2891<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2892<pre>
2893%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2894@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2895</pre>
2896<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.
2897</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2898
2899</div>
2900
2901<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2902<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2903<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2904</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2905
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2906<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2907<pre>
2908%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2909@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2910</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2911
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2912<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.
2913</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2914
2915</div>
2916
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2917</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2918
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2919<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2920<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2921<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2922
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2923<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2924
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2925<p>The LLVM instruction set consists of several different classifications of
2926 instructions: <a href="#terminators">terminator
2927 instructions</a>, <a href="#binaryops">binary instructions</a>,
2928 <a href="#bitwiseops">bitwise binary instructions</a>,
2929 <a href="#memoryops">memory instructions</a>, and
2930 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2931
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2932<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2933<h3>
2934 <a name="terminators">Terminator Instructions</a>
2935</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2936
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2937<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2938
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2939<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2940 in a program ends with a "Terminator" instruction, which indicates which
2941 block should be executed after the current block is finished. These
2942 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2943 control flow, not values (the one exception being the
2944 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2945
Bill Wendling6c923bb2011-07-27 20:18:04 +0000[diff] [blame^]2946<p>There are eight different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2947 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2948 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2949 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2950 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2951 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
Bill Wendling6c923bb2011-07-27 20:18:04 +0000[diff] [blame^]2952 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, the
2953 '<a href="#i_resume"><tt>resume</tt></a>' instruction, and the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2954 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2955
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2956<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2957<h4>
2958 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2959</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2960
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2961<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2962
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2963<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2964<pre>
2965 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]2966 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2967</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2968
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2969<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2970<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2971 a value) from a function back to the caller.</p>
2972
2973<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2974 value and then causes control flow, and one that just causes control flow to
2975 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2976
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2977<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2978<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2979 return value. The type of the return value must be a
2980 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2981
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2982<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2983 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2984 value or a return value with a type that does not match its type, or if it
2985 has a void return type and contains a '<tt>ret</tt>' instruction with a
2986 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2987
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2988<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2989<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2990 the calling function's context. If the caller is a
2991 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2992 instruction after the call. If the caller was an
2993 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2994 the beginning of the "normal" destination block. If the instruction returns
2995 a value, that value shall set the call or invoke instruction's return
2996 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2997
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2998<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2999<pre>
3000 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3001 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]3002 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]3003</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3004
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3005</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3006<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3007<h4>
3008 <a name="i_br">'<tt>br</tt>' Instruction</a>
3009</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3010
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3011<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3012
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3013<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3014<pre>
Bill Wendling16b86742011-07-26 10:41:15 +0000[diff] [blame]3015 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3016 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3017</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3018
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3019<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3020<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3021 different basic block in the current function. There are two forms of this
3022 instruction, corresponding to a conditional branch and an unconditional
3023 branch.</p>
3024
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3025<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3026<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3027 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3028 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3029 target.</p>
3030
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3031<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3032<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3033 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3034 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3035 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3036
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3037<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3038<pre>
3039Test:
3040 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3041 br i1 %cond, label %IfEqual, label %IfUnequal
3042IfEqual:
3043 <a href="#i_ret">ret</a> i32 1
3044IfUnequal:
3045 <a href="#i_ret">ret</a> i32 0
3046</pre>
3047
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3048</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3049
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3050<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3051<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3052 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3053</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3054
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3055<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3056
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3057<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3058<pre>
3059 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3060</pre>
3061
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3062<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3063<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]3064 several different places. It is a generalization of the '<tt>br</tt>'
3065 instruction, allowing a branch to occur to one of many possible
3066 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3067
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3068<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3069<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3070 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3071 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3072 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3073
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3074<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3075<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3076 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3077 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3078 transferred to the corresponding destination; otherwise, control flow is
3079 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3080
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3081<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3082<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3083 <tt>switch</tt> instruction, this instruction may be code generated in
3084 different ways. For example, it could be generated as a series of chained
3085 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3086
3087<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3088<pre>
3089 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3090 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3091 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3092
3093 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3094 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3095
3096 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3097 switch i32 %val, label %otherwise [ i32 0, label %onzero
3098 i32 1, label %onone
3099 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3100</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3101
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3102</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3103
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3104
3105<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3106<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3107 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3108</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3109
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3110<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3111
3112<h5>Syntax:</h5>
3113<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3114 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]3115</pre>
3116
3117<h5>Overview:</h5>
3118
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3119<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3120 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3121 "<tt>address</tt>". Address must be derived from a <a
3122 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3123
3124<h5>Arguments:</h5>
3125
3126<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3127 rest of the arguments indicate the full set of possible destinations that the
3128 address may point to. Blocks are allowed to occur multiple times in the
3129 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3130
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3131<p>This destination list is required so that dataflow analysis has an accurate
3132 understanding of the CFG.</p>
3133
3134<h5>Semantics:</h5>
3135
3136<p>Control transfers to the block specified in the address argument. All
3137 possible destination blocks must be listed in the label list, otherwise this
3138 instruction has undefined behavior. This implies that jumps to labels
3139 defined in other functions have undefined behavior as well.</p>
3140
3141<h5>Implementation:</h5>
3142
3143<p>This is typically implemented with a jump through a register.</p>
3144
3145<h5>Example:</h5>
3146<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3147 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3148</pre>
3149
3150</div>
3151
3152
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3153<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3154<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3155 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3156</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3157
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3158<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3159
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3160<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3161<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3162 &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]3163 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3164</pre>
3165
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3166<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3167<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3168 function, with the possibility of control flow transfer to either the
3169 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3170 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3171 control flow will return to the "normal" label. If the callee (or any
3172 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3173 instruction, control is interrupted and continued at the dynamically nearest
3174 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3175
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3176<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3177<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3178
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3179<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3180 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3181 convention</a> the call should use. If none is specified, the call
3182 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3183
3184 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3185 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3186 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3187
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3188 <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]3189 function value being invoked. In most cases, this is a direct function
3190 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3191 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3192
3193 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3194 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3195
3196 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3197 signature argument types and parameter attributes. All arguments must be
3198 of <a href="#t_firstclass">first class</a> type. If the function
3199 signature indicates the function accepts a variable number of arguments,
3200 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3201
3202 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3203 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3204
3205 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3206 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3207
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3208 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3209 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3210 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3211</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3212
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3213<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3214<p>This instruction is designed to operate as a standard
3215 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3216 primary difference is that it establishes an association with a label, which
3217 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3218
3219<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3220 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3221 exception. Additionally, this is important for implementation of
3222 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3223
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3224<p>For the purposes of the SSA form, the definition of the value returned by the
3225 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3226 block to the "normal" label. If the callee unwinds then no return value is
3227 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3228
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3229<p>Note that the code generator does not yet completely support unwind, and
3230that the invoke/unwind semantics are likely to change in future versions.</p>
3231
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3232<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3233<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3234 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3235 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3236 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3237 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3238</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3239
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3240</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3241
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3242<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3243
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3244<h4>
3245 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3246</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3247
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3248<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3249
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3250<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3251<pre>
3252 unwind
3253</pre>
3254
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3255<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3256<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3257 at the first callee in the dynamic call stack which used
3258 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3259 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3260
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3261<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3262<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3263 immediately halt. The dynamic call stack is then searched for the
3264 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3265 Once found, execution continues at the "exceptional" destination block
3266 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3267 instruction in the dynamic call chain, undefined behavior results.</p>
3268
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3269<p>Note that the code generator does not yet completely support unwind, and
3270that the invoke/unwind semantics are likely to change in future versions.</p>
3271
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3272</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3273
3274<!-- _______________________________________________________________________ -->
3275
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3276<h4>
Bill Wendling6c923bb2011-07-27 20:18:04 +0000[diff] [blame^]3277 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3278</h4>
3279
3280<div>
3281
3282<h5>Syntax:</h5>
3283<pre>
3284 resume &lt;type&gt; &lt;value&gt;
3285</pre>
3286
3287<h5>Overview:</h5>
3288<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3289 successors. Its operand must have the same type as the result of any
3290 '<tt>landingpad</tt>' instruction in the same function.</p>
3291
3292<h5>Semantics:</h5>
3293<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3294 (in-flight) exception.</p>
3295
3296<h5>Example:</h5>
3297<pre>
3298 resume { i8*, i32 } %exn
3299</pre>
3300
3301</div>
3302
3303<!-- _______________________________________________________________________ -->
3304
3305<h4>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3306 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3307</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3308
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3309<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3310
3311<h5>Syntax:</h5>
3312<pre>
3313 unreachable
3314</pre>
3315
3316<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3317<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3318 instruction is used to inform the optimizer that a particular portion of the
3319 code is not reachable. This can be used to indicate that the code after a
3320 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3321
3322<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3323<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3324
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3325</div>
3326
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3327</div>
3328
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3329<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3330<h3>
3331 <a name="binaryops">Binary Operations</a>
3332</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3333
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3334<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3335
3336<p>Binary operators are used to do most of the computation in a program. They
3337 require two operands of the same type, execute an operation on them, and
3338 produce a single value. The operands might represent multiple data, as is
3339 the case with the <a href="#t_vector">vector</a> data type. The result value
3340 has the same type as its operands.</p>
3341
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3342<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3343
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3344<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3345<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3346 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3347</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3348
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3349<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3350
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3351<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3352<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3353 &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]3354 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3355 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3356 &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]3357</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3358
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3359<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3360<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3361
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3362<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3363<p>The two arguments to the '<tt>add</tt>' instruction must
3364 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3365 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3366
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3367<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3368<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3369
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3370<p>If the sum has unsigned overflow, the result returned is the mathematical
3371 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]3372
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3373<p>Because LLVM integers use a two's complement representation, this instruction
3374 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3375
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3376<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3377 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3378 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3379 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3380 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3381
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3382<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3383<pre>
3384 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3385</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3386
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3387</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3388
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3389<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3390<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3391 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3392</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3393
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3394<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3395
3396<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3397<pre>
3398 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3399</pre>
3400
3401<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3402<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3403
3404<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3405<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3406 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3407 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3408
3409<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3410<p>The value produced is the floating point sum of the two operands.</p>
3411
3412<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3413<pre>
3414 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3415</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3416
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3417</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3418
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3419<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3420<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3421 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3422</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3423
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3424<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3425
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3426<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3427<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3428 &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]3429 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3430 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3431 &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]3432</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3433
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3434<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3435<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3436 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3437
3438<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3439 '<tt>neg</tt>' instruction present in most other intermediate
3440 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3441
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3442<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3443<p>The two arguments to the '<tt>sub</tt>' instruction must
3444 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3445 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3446
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3447<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3448<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3449
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3450<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3451 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3452 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>sub</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>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3464<pre>
3465 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3466 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3467</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3468
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3469</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3470
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3471<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3472<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3473 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3474</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3475
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3476<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3477
3478<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3479<pre>
3480 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3481</pre>
3482
3483<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3484<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3485 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3486
3487<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3488 '<tt>fneg</tt>' instruction present in most other intermediate
3489 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3490
3491<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3492<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3493 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3494 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3495
3496<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3497<p>The value produced is the floating point difference of the two operands.</p>
3498
3499<h5>Example:</h5>
3500<pre>
3501 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3502 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3503</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3504
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3505</div>
3506
3507<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3508<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3509 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3510</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3511
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3512<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3513
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3514<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3515<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3516 &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]3517 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3518 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3519 &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]3520</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3521
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3522<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3523<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3524
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3525<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3526<p>The two arguments to the '<tt>mul</tt>' instruction must
3527 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3528 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3529
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3530<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3531<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3532
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3533<p>If the result of the multiplication has unsigned overflow, the result
3534 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3535 width of the result.</p>
3536
3537<p>Because LLVM integers use a two's complement representation, and the result
3538 is the same width as the operands, this instruction returns the correct
3539 result for both signed and unsigned integers. If a full product
3540 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3541 be sign-extended or zero-extended as appropriate to the width of the full
3542 product.</p>
3543
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3544<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3545 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3546 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3547 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3548 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3549
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3550<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3551<pre>
3552 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3553</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3554
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3555</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3556
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3557<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3558<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3559 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3560</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3561
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3562<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3563
3564<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3565<pre>
3566 &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]3567</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3568
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3569<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3570<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3571
3572<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3573<p>The two arguments to the '<tt>fmul</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 product of the two operands.</p>
3579
3580<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3581<pre>
3582 &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]3583</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3584
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3585</div>
3586
3587<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3588<h4>
3589 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3590</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3591
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3592<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3593
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3594<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3595<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3596 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3597 &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]3598</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3599
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3600<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3601<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3602
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3603<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3604<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3605 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3606 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3607
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3608<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3609<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3610
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3611<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3612 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3613
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3614<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3615
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3616<p>If the <tt>exact</tt> keyword is present, the result value of the
3617 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3618 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3619
3620
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3621<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3622<pre>
3623 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3624</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3625
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3626</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3627
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3628<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3629<h4>
3630 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3631</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3632
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3633<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3634
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3635<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3636<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3637 &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]3638 &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]3639</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3640
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3641<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3642<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3643
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3644<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3645<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3646 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3647 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3648
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3649<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3650<p>The value produced is the signed integer quotient of the two operands rounded
3651 towards zero.</p>
3652
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3653<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3654 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3655
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3656<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3657 undefined behavior; this is a rare case, but can occur, for example, by doing
3658 a 32-bit division of -2147483648 by -1.</p>
3659
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3660<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3661 <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]3662 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3663
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3664<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3665<pre>
3666 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3667</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3668
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3669</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3670
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3671<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3672<h4>
3673 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3674</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3675
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3676<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3677
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3678<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3679<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3680 &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]3681</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3682
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3683<h5>Overview:</h5>
3684<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3685
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3686<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3687<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3688 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3689 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3690
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3691<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3692<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3693
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3694<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3695<pre>
3696 &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]3697</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3698
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3699</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3700
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3701<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3702<h4>
3703 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3704</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3705
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3706<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3707
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3708<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3709<pre>
3710 &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]3711</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3712
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3713<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3714<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3715 division of its two arguments.</p>
3716
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3717<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3718<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3719 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3720 values. Both arguments must have identical types.</p>
3721
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3722<h5>Semantics:</h5>
3723<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3724 This instruction always performs an unsigned division to get the
3725 remainder.</p>
3726
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3727<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3728 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3729
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3730<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3731
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3732<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3733<pre>
3734 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3735</pre>
3736
3737</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3738
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3739<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3740<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3741 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3742</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3743
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3744<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3745
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3746<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3747<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3748 &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]3749</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3750
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3751<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3752<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3753 division of its two operands. This instruction can also take
3754 <a href="#t_vector">vector</a> versions of the values in which case the
3755 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3756
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3757<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3758<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3759 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3760 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3761
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3762<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3763<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3764 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3765 <i>modulo</i> operator (where the result is either zero or has the same sign
3766 as the divisor, <tt>op2</tt>) of a value.
3767 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3768 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3769 Math Forum</a>. For a table of how this is implemented in various languages,
3770 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3771 Wikipedia: modulo operation</a>.</p>
3772
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3773<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3774 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3775
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3776<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3777 Overflow also leads to undefined behavior; this is a rare case, but can
3778 occur, for example, by taking the remainder of a 32-bit division of
3779 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3780 lets srem be implemented using instructions that return both the result of
3781 the division and the remainder.)</p>
3782
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3783<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3784<pre>
3785 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3786</pre>
3787
3788</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3789
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3790<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3791<h4>
3792 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3793</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3794
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3795<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3796
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3797<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3798<pre>
3799 &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]3800</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3801
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3802<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3803<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3804 its two operands.</p>
3805
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3806<h5>Arguments:</h5>
3807<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3808 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3809 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3810
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3811<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3812<p>This instruction returns the <i>remainder</i> of a division. The remainder
3813 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3814
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3815<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3816<pre>
3817 &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]3818</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3819
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3820</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3821
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3822</div>
3823
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3824<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3825<h3>
3826 <a name="bitwiseops">Bitwise Binary Operations</a>
3827</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3828
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3829<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3830
3831<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3832 program. They are generally very efficient instructions and can commonly be
3833 strength reduced from other instructions. They require two operands of the
3834 same type, execute an operation on them, and produce a single value. The
3835 resulting value is the same type as its operands.</p>
3836
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3837<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3838<h4>
3839 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3840</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3841
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3842<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3843
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3844<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3845<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3846 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3847 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3848 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3849 &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]3850</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3851
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3852<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3853<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3854 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3855
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3856<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3857<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3858 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3859 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3860
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3861<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3862<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3863 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3864 is (statically or dynamically) negative or equal to or larger than the number
3865 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3866 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3867 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3868
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3869<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3870 <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]3871 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3872 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3873 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3874 they would if the shift were expressed as a mul instruction with the same
3875 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3876
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3877<h5>Example:</h5>
3878<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3879 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3880 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3881 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3882 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3883 &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]3884</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3885
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3886</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3887
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3888<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3889<h4>
3890 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3891</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3892
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3893<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3894
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3895<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3896<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3897 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3898 &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]3899</pre>
3900
3901<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3902<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3903 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3904
3905<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3906<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3907 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3908 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3909
3910<h5>Semantics:</h5>
3911<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3912 significant bits of the result will be filled with zero bits after the shift.
3913 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3914 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3915 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3916 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3917
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3918<p>If the <tt>exact</tt> keyword is present, the result value of the
3919 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3920 shifted out are non-zero.</p>
3921
3922
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3923<h5>Example:</h5>
3924<pre>
3925 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3926 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3927 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3928 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3929 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3930 &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]3931</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3932
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3933</div>
3934
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3935<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3936<h4>
3937 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3938</h4>
3939
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3940<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3941
3942<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3943<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3944 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3945 &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]3946</pre>
3947
3948<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3949<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3950 operand shifted to the right a specified number of bits with sign
3951 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3952
3953<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3954<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3955 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3956 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3957
3958<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3959<p>This instruction always performs an arithmetic shift right operation, The
3960 most significant bits of the result will be filled with the sign bit
3961 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3962 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3963 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3964 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3965
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3966<p>If the <tt>exact</tt> keyword is present, the result value of the
3967 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3968 shifted out are non-zero.</p>
3969
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3970<h5>Example:</h5>
3971<pre>
3972 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3973 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3974 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3975 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3976 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3977 &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]3978</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3979
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3980</div>
3981
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3982<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3983<h4>
3984 <a name="i_and">'<tt>and</tt>' Instruction</a>
3985</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3986
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3987<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3988
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3989<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3990<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3991 &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]3992</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3993
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3994<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3995<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3996 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3997
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3998<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3999<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4000 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4001 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4002
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4003<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4004<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4005
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4006<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4007 <tbody>
4008 <tr>
4009 <td>In0</td>
4010 <td>In1</td>
4011 <td>Out</td>
4012 </tr>
4013 <tr>
4014 <td>0</td>
4015 <td>0</td>
4016 <td>0</td>
4017 </tr>
4018 <tr>
4019 <td>0</td>
4020 <td>1</td>
4021 <td>0</td>
4022 </tr>
4023 <tr>
4024 <td>1</td>
4025 <td>0</td>
4026 <td>0</td>
4027 </tr>
4028 <tr>
4029 <td>1</td>
4030 <td>1</td>
4031 <td>1</td>
4032 </tr>
4033 </tbody>
4034</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4035
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4036<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4037<pre>
4038 &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]4039 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4040 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4041</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4042</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4043<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4044<h4>
4045 <a name="i_or">'<tt>or</tt>' Instruction</a>
4046</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4047
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4048<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4049
4050<h5>Syntax:</h5>
4051<pre>
4052 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4053</pre>
4054
4055<h5>Overview:</h5>
4056<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4057 two operands.</p>
4058
4059<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4060<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4061 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4062 values. Both arguments must have identical types.</p>
4063
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4064<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4065<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4066
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4067<table border="1" cellspacing="0" cellpadding="4">
4068 <tbody>
4069 <tr>
4070 <td>In0</td>
4071 <td>In1</td>
4072 <td>Out</td>
4073 </tr>
4074 <tr>
4075 <td>0</td>
4076 <td>0</td>
4077 <td>0</td>
4078 </tr>
4079 <tr>
4080 <td>0</td>
4081 <td>1</td>
4082 <td>1</td>
4083 </tr>
4084 <tr>
4085 <td>1</td>
4086 <td>0</td>
4087 <td>1</td>
4088 </tr>
4089 <tr>
4090 <td>1</td>
4091 <td>1</td>
4092 <td>1</td>
4093 </tr>
4094 </tbody>
4095</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4096
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4097<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4098<pre>
4099 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4100 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4101 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4102</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4103
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4104</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4105
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4106<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4107<h4>
4108 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4109</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4110
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4111<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4112
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4113<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4114<pre>
4115 &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]4116</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4117
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4118<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4119<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4120 its two operands. The <tt>xor</tt> is used to implement the "one's
4121 complement" operation, which is the "~" operator in C.</p>
4122
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4123<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4124<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4125 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4126 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4127
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4128<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4129<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4130
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4131<table border="1" cellspacing="0" cellpadding="4">
4132 <tbody>
4133 <tr>
4134 <td>In0</td>
4135 <td>In1</td>
4136 <td>Out</td>
4137 </tr>
4138 <tr>
4139 <td>0</td>
4140 <td>0</td>
4141 <td>0</td>
4142 </tr>
4143 <tr>
4144 <td>0</td>
4145 <td>1</td>
4146 <td>1</td>
4147 </tr>
4148 <tr>
4149 <td>1</td>
4150 <td>0</td>
4151 <td>1</td>
4152 </tr>
4153 <tr>
4154 <td>1</td>
4155 <td>1</td>
4156 <td>0</td>
4157 </tr>
4158 </tbody>
4159</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4160
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4161<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4162<pre>
4163 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4164 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4165 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4166 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4167</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4168
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4169</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4170
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4171</div>
4172
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4173<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4174<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4175 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4176</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4177
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4178<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4179
4180<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4181 target-independent manner. These instructions cover the element-access and
4182 vector-specific operations needed to process vectors effectively. While LLVM
4183 does directly support these vector operations, many sophisticated algorithms
4184 will want to use target-specific intrinsics to take full advantage of a
4185 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4186
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4187<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4188<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4189 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4190</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4191
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4192<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4193
4194<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4195<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4196 &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]4197</pre>
4198
4199<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4200<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4201 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4202
4203
4204<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4205<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4206 of <a href="#t_vector">vector</a> type. The second operand is an index
4207 indicating the position from which to extract the element. The index may be
4208 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4209
4210<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4211<p>The result is a scalar of the same type as the element type of
4212 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4213 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4214 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4215
4216<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4217<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4218 &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]4219</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4220
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4221</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4222
4223<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4224<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4225 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4226</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4227
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4228<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4229
4230<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4231<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4232 &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]4233</pre>
4234
4235<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4236<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4237 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4238
4239<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4240<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4241 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4242 whose type must equal the element type of the first operand. The third
4243 operand is an index indicating the position at which to insert the value.
4244 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4245
4246<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4247<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4248 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4249 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4250 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4251
4252<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4253<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4254 &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]4255</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4256
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4257</div>
4258
4259<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4260<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4261 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4262</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4263
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4264<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4265
4266<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4267<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4268 &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]4269</pre>
4270
4271<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4272<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4273 from two input vectors, returning a vector with the same element type as the
4274 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4275
4276<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4277<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4278 with types that match each other. The third argument is a shuffle mask whose
4279 element type is always 'i32'. The result of the instruction is a vector
4280 whose length is the same as the shuffle mask and whose element type is the
4281 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4282
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4283<p>The shuffle mask operand is required to be a constant vector with either
4284 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4285
4286<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4287<p>The elements of the two input vectors are numbered from left to right across
4288 both of the vectors. The shuffle mask operand specifies, for each element of
4289 the result vector, which element of the two input vectors the result element
4290 gets. The element selector may be undef (meaning "don't care") and the
4291 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4292
4293<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4294<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4295 &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]4296 &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]4297 &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]4298 &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]4299 &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]4300 &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]4301 &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]4302 &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]4303</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4304
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4305</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4306
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4307</div>
4308
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4309<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4310<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4311 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4312</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4313
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4314<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4315
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4316<p>LLVM supports several instructions for working with
4317 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4318
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4319<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4320<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4321 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4322</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4323
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4324<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4325
4326<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4327<pre>
4328 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4329</pre>
4330
4331<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4332<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4333 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4334
4335<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4336<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4337 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4338 <a href="#t_array">array</a> type. The operands are constant indices to
4339 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4340 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4341 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4342 <ul>
4343 <li>Since the value being indexed is not a pointer, the first index is
4344 omitted and assumed to be zero.</li>
4345 <li>At least one index must be specified.</li>
4346 <li>Not only struct indices but also array indices must be in
4347 bounds.</li>
4348 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4349
4350<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4351<p>The result is the value at the position in the aggregate specified by the
4352 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4353
4354<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4355<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4356 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4357</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4358
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4359</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4360
4361<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4362<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4363 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4364</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4365
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4366<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4367
4368<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4369<pre>
Bill Wendlingf6a91cf2011-07-26 20:42:28 +0000[diff] [blame]4370 &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]4371</pre>
4372
4373<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4374<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4375 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4376
4377<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4378<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4379 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4380 <a href="#t_array">array</a> type. The second operand is a first-class
4381 value to insert. The following operands are constant indices indicating
4382 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]4383 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4384 value to insert must have the same type as the value identified by the
4385 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4386
4387<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4388<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4389 that of <tt>val</tt> except that the value at the position specified by the
4390 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4391
4392<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4393<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4394 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4395 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4396 %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]4397</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4398
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4399</div>
4400
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4401</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4402
4403<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4404<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4405 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4406</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4407
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4408<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4409
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4410<p>A key design point of an SSA-based representation is how it represents
4411 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4412 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4413 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4414
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4415<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4416<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4417 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4418</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4419
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4420<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4421
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4422<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4423<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4424 &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]4425</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4426
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4427<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4428<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4429 currently executing function, to be automatically released when this function
4430 returns to its caller. The object is always allocated in the generic address
4431 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4432
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4433<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4434<p>The '<tt>alloca</tt>' instruction
4435 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4436 runtime stack, returning a pointer of the appropriate type to the program.
4437 If "NumElements" is specified, it is the number of elements allocated,
4438 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4439 specified, the value result of the allocation is guaranteed to be aligned to
4440 at least that boundary. If not specified, or if zero, the target can choose
4441 to align the allocation on any convenient boundary compatible with the
4442 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4443
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4444<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4445
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4446<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4447<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4448 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4449 memory is automatically released when the function returns. The
4450 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4451 variables that must have an address available. When the function returns
4452 (either with the <tt><a href="#i_ret">ret</a></tt>
4453 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4454 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4455
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4456<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4457<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4458 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4459 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4460 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4461 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4462</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4463
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4464</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4465
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4466<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4467<h4>
4468 <a name="i_load">'<tt>load</tt>' Instruction</a>
4469</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4470
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4471<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4472
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4473<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4474<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4475 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4476 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4477 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4478</pre>
4479
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4480<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4481<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4482
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4483<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4484<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4485 from which to load. The pointer must point to
4486 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4487 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4488 number or order of execution of this <tt>load</tt> with other <a
4489 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4490
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4491<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4492 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]4493 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4494 alignment for the target. It is the responsibility of the code emitter to
4495 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4496 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4497 produce less efficient code. An alignment of 1 is always safe.</p>
4498
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4499<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4500 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4501 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4502 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4503 and code generator that this load is not expected to be reused in the cache.
4504 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4505 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4506
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4507<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4508<p>The location of memory pointed to is loaded. If the value being loaded is of
4509 scalar type then the number of bytes read does not exceed the minimum number
4510 of bytes needed to hold all bits of the type. For example, loading an
4511 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4512 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4513 is undefined if the value was not originally written using a store of the
4514 same type.</p>
4515
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4516<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4517<pre>
4518 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4519 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4520 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4521</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4522
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4523</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4524
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4525<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4526<h4>
4527 <a name="i_store">'<tt>store</tt>' Instruction</a>
4528</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4529
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4530<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4531
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4532<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4533<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4534 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>
4535 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]4536</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4537
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4538<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4539<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4540
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4541<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4542<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4543 and an address at which to store it. The type of the
4544 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4545 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4546 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4547 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4548 order of execution of this <tt>store</tt> with other <a
4549 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4550
4551<p>The optional constant "align" argument specifies the alignment of the
4552 operation (that is, the alignment of the memory address). A value of 0 or an
4553 omitted "align" argument means that the operation has the preferential
4554 alignment for the target. It is the responsibility of the code emitter to
4555 ensure that the alignment information is correct. Overestimating the
4556 alignment results in an undefined behavior. Underestimating the alignment may
4557 produce less efficient code. An alignment of 1 is always safe.</p>
4558
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4559<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4560 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4561 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4562 instruction tells the optimizer and code generator that this load is
4563 not expected to be reused in the cache. The code generator may
4564 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4565 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4566
4567
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4568<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4569<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4570 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4571 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4572 does not exceed the minimum number of bytes needed to hold all bits of the
4573 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4574 writing a value of a type like <tt>i20</tt> with a size that is not an
4575 integral number of bytes, it is unspecified what happens to the extra bits
4576 that do not belong to the type, but they will typically be overwritten.</p>
4577
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4578<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4579<pre>
4580 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4581 store i32 3, i32* %ptr <i>; yields {void}</i>
4582 %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]4583</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4584
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4585</div>
4586
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4587<!-- _______________________________________________________________________ -->
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]4588<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4589Instruction</a> </div>
4590
4591<div class="doc_text">
4592
4593<h5>Syntax:</h5>
4594<pre>
4595 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4596</pre>
4597
4598<h5>Overview:</h5>
4599<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4600between operations.</p>
4601
4602<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4603href="#ordering">ordering</a> argument which defines what
4604<i>synchronizes-with</i> edges they add. They can only be given
4605<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4606<code>seq_cst</code> orderings.</p>
4607
4608<h5>Semantics:</h5>
4609<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4610semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4611<code>acquire</code> ordering semantics if and only if there exist atomic
4612operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4613<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4614<var>X</var> modifies <var>M</var> (either directly or through some side effect
4615of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4616<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4617<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4618than an explicit <code>fence</code>, one (but not both) of the atomic operations
4619<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4620<code>acquire</code> (resp.) ordering constraint and still
4621<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4622<i>happens-before</i> edge.</p>
4623
4624<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4625having both <code>acquire</code> and <code>release</code> semantics specified
4626above, participates in the global program order of other <code>seq_cst</code>
4627operations and/or fences.</p>
4628
4629<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4630specifies that the fence only synchronizes with other fences in the same
4631thread. (This is useful for interacting with signal handlers.)</p>
4632
4633<p>FIXME: This instruction is a work in progress; until it is finished, use
4634 llvm.memory.barrier.
4635
4636<h5>Example:</h5>
4637<pre>
4638 fence acquire <i>; yields {void}</i>
4639 fence singlethread seq_cst <i>; yields {void}</i>
4640</pre>
4641
4642</div>
4643
4644<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4645<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4646 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4647</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4648
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4649<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4650
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4651<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4652<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4653 &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]4654 &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]4655</pre>
4656
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4657<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4658<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4659 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4660 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4661
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4662<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4663<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4664 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4665 elements of the aggregate object are indexed. The interpretation of each
4666 index is dependent on the type being indexed into. The first index always
4667 indexes the pointer value given as the first argument, the second index
4668 indexes a value of the type pointed to (not necessarily the value directly
4669 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4670 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4671 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4672 can never be pointers, since that would require loading the pointer before
4673 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4674
4675<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]4676 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4677 integer <b>constants</b> are allowed. When indexing into an array, pointer
4678 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]4679 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4680
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4681<p>For example, let's consider a C code fragment and how it gets compiled to
4682 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4683
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4684<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4685struct RT {
4686 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4687 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4688 char C;
4689};
4690struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4691 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4692 double Y;
4693 struct RT Z;
4694};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4695
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4696int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4697 return &amp;s[1].Z.B[5][13];
4698}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4699</pre>
4700
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4701<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4702
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4703<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4704%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4705%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4706
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4707define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4708entry:
4709 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4710 ret i32* %reg
4711}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4712</pre>
4713
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4714<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4715<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]4716 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4717 }</tt>' type, a structure. The second index indexes into the third element
4718 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4719 i8 }</tt>' type, another structure. The third index indexes into the second
4720 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4721 array. The two dimensions of the array are subscripted into, yielding an
4722 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4723 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4724
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4725<p>Note that it is perfectly legal to index partially through a structure,
4726 returning a pointer to an inner element. Because of this, the LLVM code for
4727 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4728
4729<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4730 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4731 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4732 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4733 %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]4734 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4735 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4736 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4737 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4738</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4739
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4740<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4741 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4742 base pointer is not an <i>in bounds</i> address of an allocated object,
4743 or if any of the addresses that would be formed by successive addition of
4744 the offsets implied by the indices to the base address with infinitely
4745 precise arithmetic are not an <i>in bounds</i> address of that allocated
4746 object. The <i>in bounds</i> addresses for an allocated object are all
4747 the addresses that point into the object, plus the address one byte past
4748 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4749
4750<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4751 the base address with silently-wrapping two's complement arithmetic, and
4752 the result value of the <tt>getelementptr</tt> may be outside the object
4753 pointed to by the base pointer. The result value may not necessarily be
4754 used to access memory though, even if it happens to point into allocated
4755 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4756 section for more information.</p>
4757
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4758<p>The getelementptr instruction is often confusing. For some more insight into
4759 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4760
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4761<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4762<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4763 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4764 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4765 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4766 %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]4767 <i>; yields i8*:eptr</i>
4768 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4769 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4770 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4771</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4772
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4773</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4774
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4775</div>
4776
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4777<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4778<h3>
4779 <a name="convertops">Conversion Operations</a>
4780</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4781
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4782<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4783
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4784<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4785 which all take a single operand and a type. They perform various bit
4786 conversions on the operand.</p>
4787
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4788<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4789<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4790 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4791</h4>
4792
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4793<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4794
4795<h5>Syntax:</h5>
4796<pre>
4797 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4798</pre>
4799
4800<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4801<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4802 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4803
4804<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4805<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4806 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4807 of the same number of integers.
4808 The bit size of the <tt>value</tt> must be larger than
4809 the bit size of the destination type, <tt>ty2</tt>.
4810 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4811
4812<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4813<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4814 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4815 source size must be larger than the destination size, <tt>trunc</tt> cannot
4816 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4817
4818<h5>Example:</h5>
4819<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4820 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4821 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4822 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4823 %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]4824</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4825
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4826</div>
4827
4828<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4829<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4830 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4831</h4>
4832
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4833<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4834
4835<h5>Syntax:</h5>
4836<pre>
4837 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4838</pre>
4839
4840<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4841<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4842 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4843
4844
4845<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4846<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4847 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4848 of the same number of integers.
4849 The bit size of the <tt>value</tt> must be smaller than
4850 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4851 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4852
4853<h5>Semantics:</h5>
4854<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]4855 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4856
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4857<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]4858
4859<h5>Example:</h5>
4860<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4861 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4862 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4863 %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]4864</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4865
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4866</div>
4867
4868<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4869<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4870 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4871</h4>
4872
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4873<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4874
4875<h5>Syntax:</h5>
4876<pre>
4877 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4878</pre>
4879
4880<h5>Overview:</h5>
4881<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4882
4883<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4884<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4885 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4886 of the same number of integers.
4887 The bit size of the <tt>value</tt> must be smaller than
4888 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4889 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4890
4891<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4892<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4893 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4894 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4895
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4896<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]4897
4898<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4899<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4900 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4901 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4902 %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]4903</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4904
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4905</div>
4906
4907<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4908<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4909 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4910</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4911
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4912<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4913
4914<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4915<pre>
4916 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4917</pre>
4918
4919<h5>Overview:</h5>
4920<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4921 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4922
4923<h5>Arguments:</h5>
4924<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4925 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4926 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]4927 <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]4928 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4929
4930<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4931<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4932 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4933 <a href="#t_floating">floating point</a> type. If the value cannot fit
4934 within the destination type, <tt>ty2</tt>, then the results are
4935 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4936
4937<h5>Example:</h5>
4938<pre>
4939 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4940 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4941</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4942
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4943</div>
4944
4945<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4946<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4947 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4948</h4>
4949
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4950<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4951
4952<h5>Syntax:</h5>
4953<pre>
4954 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4955</pre>
4956
4957<h5>Overview:</h5>
4958<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]4959 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4960
4961<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4962<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4963 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4964 a <a href="#t_floating">floating point</a> type to cast it to. The source
4965 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4966
4967<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4968<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4969 <a href="#t_floating">floating point</a> type to a larger
4970 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4971 used to make a <i>no-op cast</i> because it always changes bits. Use
4972 <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]4973
4974<h5>Example:</h5>
4975<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]4976 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4977 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4978</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4979
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4980</div>
4981
4982<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4983<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4984 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4985</h4>
4986
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4987<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4988
4989<h5>Syntax:</h5>
4990<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4991 &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]4992</pre>
4993
4994<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4995<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4996 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4997
4998<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4999<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5000 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5001 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5002 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5003 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5004
5005<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5006<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5007 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5008 towards zero) unsigned integer value. If the value cannot fit
5009 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5010
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5011<h5>Example:</h5>
5012<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5013 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5014 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5015 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5016</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5017
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5018</div>
5019
5020<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5021<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5022 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5023</h4>
5024
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5025<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5026
5027<h5>Syntax:</h5>
5028<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5029 &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]5030</pre>
5031
5032<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5033<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5034 <a href="#t_floating">floating point</a> <tt>value</tt> to
5035 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5036
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5037<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5038<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5039 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5040 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5041 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5042 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5043
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5044<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5045<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5046 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5047 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5048 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5049
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5050<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5051<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5052 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5053 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5054 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5055</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5056
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5057</div>
5058
5059<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5060<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5061 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5062</h4>
5063
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5064<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5065
5066<h5>Syntax:</h5>
5067<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5068 &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]5069</pre>
5070
5071<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5072<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5073 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5074
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5075<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5076<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]5077 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5078 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5079 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5080 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5081
5082<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5083<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5084 integer quantity and converts it to the corresponding floating point
5085 value. If the value cannot fit in the floating point value, the results are
5086 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5087
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5088<h5>Example:</h5>
5089<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5090 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5091 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5092</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5093
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5094</div>
5095
5096<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5097<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5098 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5099</h4>
5100
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5101<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5102
5103<h5>Syntax:</h5>
5104<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5105 &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]5106</pre>
5107
5108<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5109<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5110 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5111
5112<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5113<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]5114 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5115 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5116 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5117 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5118
5119<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5120<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5121 quantity and converts it to the corresponding floating point value. If the
5122 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5123
5124<h5>Example:</h5>
5125<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5126 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5127 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5128</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5129
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5130</div>
5131
5132<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5133<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5134 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5135</h4>
5136
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5137<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5138
5139<h5>Syntax:</h5>
5140<pre>
5141 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5142</pre>
5143
5144<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5145<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5146 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5147
5148<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5149<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5150 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5151 <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]5152
5153<h5>Semantics:</h5>
5154<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5155 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5156 truncating or zero extending that value to the size of the integer type. If
5157 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5158 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5159 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5160 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5161
5162<h5>Example:</h5>
5163<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5164 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5165 %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]5166</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5167
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5168</div>
5169
5170<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5171<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5172 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5173</h4>
5174
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5175<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5176
5177<h5>Syntax:</h5>
5178<pre>
5179 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5180</pre>
5181
5182<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5183<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5184 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5185
5186<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5187<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5188 value to cast, and a type to cast it to, which must be a
5189 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5190
5191<h5>Semantics:</h5>
5192<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5193 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5194 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5195 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5196 than the size of a pointer then a zero extension is done. If they are the
5197 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5198
5199<h5>Example:</h5>
5200<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5201 %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]5202 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5203 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5204</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5205
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5206</div>
5207
5208<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5209<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5210 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5211</h4>
5212
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5213<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5214
5215<h5>Syntax:</h5>
5216<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5217 &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]5218</pre>
5219
5220<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5221<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5222 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5223
5224<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5225<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5226 non-aggregate first class value, and a type to cast it to, which must also be
5227 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5228 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5229 identical. If the source type is a pointer, the destination type must also be
5230 a pointer. This instruction supports bitwise conversion of vectors to
5231 integers and to vectors of other types (as long as they have the same
5232 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5233
5234<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5235<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5236 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5237 this conversion. The conversion is done as if the <tt>value</tt> had been
5238 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5239 be converted to other pointer types with this instruction. To convert
5240 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5241 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5242
5243<h5>Example:</h5>
5244<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5245 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5246 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5247 %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]5248</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5249
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5250</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5251
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5252</div>
5253
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5254<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5255<h3>
5256 <a name="otherops">Other Operations</a>
5257</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5258
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5259<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5260
5261<p>The instructions in this category are the "miscellaneous" instructions, which
5262 defy better classification.</p>
5263
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5264<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5265<h4>
5266 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5267</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5268
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5269<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5270
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5271<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5272<pre>
5273 &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]5274</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5275
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5276<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5277<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5278 boolean values based on comparison of its two integer, integer vector, or
5279 pointer operands.</p>
5280
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5281<h5>Arguments:</h5>
5282<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5283 the condition code indicating the kind of comparison to perform. It is not a
5284 value, just a keyword. The possible condition code are:</p>
5285
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5286<ol>
5287 <li><tt>eq</tt>: equal</li>
5288 <li><tt>ne</tt>: not equal </li>
5289 <li><tt>ugt</tt>: unsigned greater than</li>
5290 <li><tt>uge</tt>: unsigned greater or equal</li>
5291 <li><tt>ult</tt>: unsigned less than</li>
5292 <li><tt>ule</tt>: unsigned less or equal</li>
5293 <li><tt>sgt</tt>: signed greater than</li>
5294 <li><tt>sge</tt>: signed greater or equal</li>
5295 <li><tt>slt</tt>: signed less than</li>
5296 <li><tt>sle</tt>: signed less or equal</li>
5297</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5298
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5299<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5300 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5301 typed. They must also be identical types.</p>
5302
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5303<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5304<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5305 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5306 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]5307 result, as follows:</p>
5308
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5309<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5310 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5311 <tt>false</tt> otherwise. No sign interpretation is necessary or
5312 performed.</li>
5313
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5314 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5315 <tt>false</tt> otherwise. No sign interpretation is necessary or
5316 performed.</li>
5317
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5318 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5319 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5320
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5321 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5322 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5323 to <tt>op2</tt>.</li>
5324
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5325 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5326 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5327
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5328 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5329 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5330
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5331 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5332 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5333
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5334 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5335 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5336 to <tt>op2</tt>.</li>
5337
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5338 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5339 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5340
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5341 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5342 <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]5343</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5344
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5345<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5346 values are compared as if they were integers.</p>
5347
5348<p>If the operands are integer vectors, then they are compared element by
5349 element. The result is an <tt>i1</tt> vector with the same number of elements
5350 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5351
5352<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5353<pre>
5354 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5355 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5356 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5357 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5358 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5359 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5360</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5361
5362<p>Note that the code generator does not yet support vector types with
5363 the <tt>icmp</tt> instruction.</p>
5364
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5365</div>
5366
5367<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5368<h4>
5369 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5370</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5371
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5372<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5373
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5374<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5375<pre>
5376 &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]5377</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5378
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5379<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5380<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5381 values based on comparison of its operands.</p>
5382
5383<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]5384(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5385
5386<p>If the operands are floating point vectors, then the result type is a vector
5387 of boolean with the same number of elements as the operands being
5388 compared.</p>
5389
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5390<h5>Arguments:</h5>
5391<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5392 the condition code indicating the kind of comparison to perform. It is not a
5393 value, just a keyword. The possible condition code are:</p>
5394
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5395<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5396 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5397 <li><tt>oeq</tt>: ordered and equal</li>
5398 <li><tt>ogt</tt>: ordered and greater than </li>
5399 <li><tt>oge</tt>: ordered and greater than or equal</li>
5400 <li><tt>olt</tt>: ordered and less than </li>
5401 <li><tt>ole</tt>: ordered and less than or equal</li>
5402 <li><tt>one</tt>: ordered and not equal</li>
5403 <li><tt>ord</tt>: ordered (no nans)</li>
5404 <li><tt>ueq</tt>: unordered or equal</li>
5405 <li><tt>ugt</tt>: unordered or greater than </li>
5406 <li><tt>uge</tt>: unordered or greater than or equal</li>
5407 <li><tt>ult</tt>: unordered or less than </li>
5408 <li><tt>ule</tt>: unordered or less than or equal</li>
5409 <li><tt>une</tt>: unordered or not equal</li>
5410 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5411 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5412</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5413
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5414<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5415 <i>unordered</i> means that either operand may be a QNAN.</p>
5416
5417<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5418 a <a href="#t_floating">floating point</a> type or
5419 a <a href="#t_vector">vector</a> of floating point type. They must have
5420 identical types.</p>
5421
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5422<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5423<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5424 according to the condition code given as <tt>cond</tt>. If the operands are
5425 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5426 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5427 follows:</p>
5428
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5429<ol>
5430 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5431
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5432 <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]5433 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5434
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5435 <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]5436 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5437
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5438 <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]5439 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5440
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5441 <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]5442 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5443
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5444 <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]5445 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5446
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5447 <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]5448 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5449
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5450 <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]5451
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5452 <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]5453 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5454
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5455 <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]5456 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5457
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5458 <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]5459 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5460
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5461 <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]5462 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5463
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5464 <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]5465 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5466
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5467 <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]5468 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5469
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5470 <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]5471
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5472 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5473</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5474
5475<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5476<pre>
5477 &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]5478 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5479 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5480 &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]5481</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5482
5483<p>Note that the code generator does not yet support vector types with
5484 the <tt>fcmp</tt> instruction.</p>
5485
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5486</div>
5487
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5488<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5489<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5490 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5491</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5492
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5493<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5494
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5495<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5496<pre>
5497 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5498</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5499
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5500<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5501<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5502 SSA graph representing the function.</p>
5503
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5504<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5505<p>The type of the incoming values is specified with the first type field. After
5506 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5507 one pair for each predecessor basic block of the current block. Only values
5508 of <a href="#t_firstclass">first class</a> type may be used as the value
5509 arguments to the PHI node. Only labels may be used as the label
5510 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5511
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5512<p>There must be no non-phi instructions between the start of a basic block and
5513 the PHI instructions: i.e. PHI instructions must be first in a basic
5514 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5515
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5516<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5517 occur on the edge from the corresponding predecessor block to the current
5518 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5519 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5520
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5521<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5522<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5523 specified by the pair corresponding to the predecessor basic block that
5524 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5525
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5526<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5527<pre>
5528Loop: ; Infinite loop that counts from 0 on up...
5529 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5530 %nextindvar = add i32 %indvar, 1
5531 br label %Loop
5532</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5533
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5534</div>
5535
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5536<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5537<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5538 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5539</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5540
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5541<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5542
5543<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5544<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5545 &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>
5546
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5547 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5548</pre>
5549
5550<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5551<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5552 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5553
5554
5555<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5556<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5557 values indicating the condition, and two values of the
5558 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5559 vectors and the condition is a scalar, then entire vectors are selected, not
5560 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5561
5562<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5563<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5564 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5565
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5566<p>If the condition is a vector of i1, then the value arguments must be vectors
5567 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5568
5569<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5570<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5571 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5572</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5573
5574<p>Note that the code generator does not yet support conditions
5575 with vector type.</p>
5576
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5577</div>
5578
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5579<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5580<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5581 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5582</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5583
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5584<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5585
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5586<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5587<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5588 &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]5589</pre>
5590
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5591<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5592<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5593
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5594<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5595<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5596
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5597<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5598 <li>The optional "tail" marker indicates that the callee function does not
5599 access any allocas or varargs in the caller. Note that calls may be
5600 marked "tail" even if they do not occur before
5601 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5602 present, the function call is eligible for tail call optimization,
5603 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5604 optimized into a jump</a>. The code generator may optimize calls marked
5605 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5606 sibling call optimization</a> when the caller and callee have
5607 matching signatures, or 2) forced tail call optimization when the
5608 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5609 <ul>
5610 <li>Caller and callee both have the calling
5611 convention <tt>fastcc</tt>.</li>
5612 <li>The call is in tail position (ret immediately follows call and ret
5613 uses value of call or is void).</li>
5614 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5615 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5616 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5617 constraints are met.</a></li>
5618 </ul>
5619 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5620
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5621 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5622 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5623 defaults to using C calling conventions. The calling convention of the
5624 call must match the calling convention of the target function, or else the
5625 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5626
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5627 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5628 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5629 '<tt>inreg</tt>' attributes are valid here.</li>
5630
5631 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5632 type of the return value. Functions that return no value are marked
5633 <tt><a href="#t_void">void</a></tt>.</li>
5634
5635 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5636 being invoked. The argument types must match the types implied by this
5637 signature. This type can be omitted if the function is not varargs and if
5638 the function type does not return a pointer to a function.</li>
5639
5640 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5641 be invoked. In most cases, this is a direct function invocation, but
5642 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5643 to function value.</li>
5644
5645 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5646 signature argument types and parameter attributes. All arguments must be
5647 of <a href="#t_firstclass">first class</a> type. If the function
5648 signature indicates the function accepts a variable number of arguments,
5649 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5650
5651 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5652 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5653 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5654</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5655
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5656<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5657<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5658 a specified function, with its incoming arguments bound to the specified
5659 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5660 function, control flow continues with the instruction after the function
5661 call, and the return value of the function is bound to the result
5662 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5663
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5664<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5665<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5666 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5667 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5668 %X = tail call i32 @foo() <i>; yields i32</i>
5669 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5670 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5671
5672 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5673 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5674 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5675 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5676 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5677 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5678</pre>
5679
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5680<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5681standard C99 library as being the C99 library functions, and may perform
5682optimizations or generate code for them under that assumption. This is
5683something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5684freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5685
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5686</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5687
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5688<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5689<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5690 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5691</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5692
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5693<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5694
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5695<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5696<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5697 &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]5698</pre>
5699
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5700<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5701<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5702 the "variable argument" area of a function call. It is used to implement the
5703 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5704
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5705<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5706<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5707 argument. It returns a value of the specified argument type and increments
5708 the <tt>va_list</tt> to point to the next argument. The actual type
5709 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5710
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5711<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5712<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5713 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5714 to the next argument. For more information, see the variable argument
5715 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5716
5717<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]5718 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5719 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5720
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5721<p><tt>va_arg</tt> is an LLVM instruction instead of
5722 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5723 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5724
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5725<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5726<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5727
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5728<p>Note that the code generator does not yet fully support va_arg on many
5729 targets. Also, it does not currently support va_arg with aggregate types on
5730 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5731
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5732</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5733
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5734</div>
5735
5736</div>
5737
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5738<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5739<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5740<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5741
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5742<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5743
5744<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5745 well known names and semantics and are required to follow certain
5746 restrictions. Overall, these intrinsics represent an extension mechanism for
5747 the LLVM language that does not require changing all of the transformations
5748 in LLVM when adding to the language (or the bitcode reader/writer, the
5749 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5750
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5751<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5752 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5753 begin with this prefix. Intrinsic functions must always be external
5754 functions: you cannot define the body of intrinsic functions. Intrinsic
5755 functions may only be used in call or invoke instructions: it is illegal to
5756 take the address of an intrinsic function. Additionally, because intrinsic
5757 functions are part of the LLVM language, it is required if any are added that
5758 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5759
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5760<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5761 family of functions that perform the same operation but on different data
5762 types. Because LLVM can represent over 8 million different integer types,
5763 overloading is used commonly to allow an intrinsic function to operate on any
5764 integer type. One or more of the argument types or the result type can be
5765 overloaded to accept any integer type. Argument types may also be defined as
5766 exactly matching a previous argument's type or the result type. This allows
5767 an intrinsic function which accepts multiple arguments, but needs all of them
5768 to be of the same type, to only be overloaded with respect to a single
5769 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5770
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5771<p>Overloaded intrinsics will have the names of its overloaded argument types
5772 encoded into its function name, each preceded by a period. Only those types
5773 which are overloaded result in a name suffix. Arguments whose type is matched
5774 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5775 can take an integer of any width and returns an integer of exactly the same
5776 integer width. This leads to a family of functions such as
5777 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5778 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5779 suffix is required. Because the argument's type is matched against the return
5780 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5781
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5782<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5783 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5784
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5785<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5786<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5787 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5788</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5789
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5790<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5791
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5792<p>Variable argument support is defined in LLVM with
5793 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5794 intrinsic functions. These functions are related to the similarly named
5795 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5796
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5797<p>All of these functions operate on arguments that use a target-specific value
5798 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5799 not define what this type is, so all transformations should be prepared to
5800 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5801
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5802<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]5803 instruction and the variable argument handling intrinsic functions are
5804 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5805
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5806<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5807define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5808 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5809 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5810 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5811 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5812
5813 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5814 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5815
5816 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5817 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5818 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5819 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5820 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5821
5822 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5823 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5824 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5825}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5826
5827declare void @llvm.va_start(i8*)
5828declare void @llvm.va_copy(i8*, i8*)
5829declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5830</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5831
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5832<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5833<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5834 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5835</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5836
5837
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5838<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5839
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5840<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5841<pre>
5842 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5843</pre>
5844
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5845<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5846<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5847 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]5848
5849<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5850<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]5851
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5852<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5853<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]5854 macro available in C. In a target-dependent way, it initializes
5855 the <tt>va_list</tt> element to which the argument points, so that the next
5856 call to <tt>va_arg</tt> will produce the first variable argument passed to
5857 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5858 need to know the last argument of the function as the compiler can figure
5859 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5860
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5861</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5862
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5863<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5864<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5865 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5866</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5867
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5868<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5869
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5870<h5>Syntax:</h5>
5871<pre>
5872 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5873</pre>
5874
5875<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5876<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5877 which has been initialized previously
5878 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5879 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5880
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5881<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5882<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]5883
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5884<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5885<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]5886 macro available in C. In a target-dependent way, it destroys
5887 the <tt>va_list</tt> element to which the argument points. Calls
5888 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5889 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5890 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5891
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5892</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5893
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5894<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5895<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5896 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5897</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5898
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5899<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5900
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5901<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5902<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5903 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5904</pre>
5905
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5906<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5907<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5908 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5909
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5910<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5911<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]5912 The second argument is a pointer to a <tt>va_list</tt> element to copy
5913 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5914
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5915<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5916<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]5917 macro available in C. In a target-dependent way, it copies the
5918 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5919 element. This intrinsic is necessary because
5920 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5921 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5922
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5923</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5924
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5925</div>
5926
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5927<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5928<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5929 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5930</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5931
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5932<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5933
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5934<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5935Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5936intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5937roots on the stack</a>, as well as garbage collector implementations that
5938require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5939barriers. Front-ends for type-safe garbage collected languages should generate
5940these intrinsics to make use of the LLVM garbage collectors. For more details,
5941see <a href="GarbageCollection.html">Accurate Garbage Collection with
5942LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5943
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5944<p>The garbage collection intrinsics only operate on objects in the generic
5945 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5946
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5947<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5948<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5949 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5950</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5951
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5952<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5953
5954<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5955<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5956 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5957</pre>
5958
5959<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5960<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]5961 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5962
5963<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5964<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5965 root pointer. The second pointer (which must be either a constant or a
5966 global value address) contains the meta-data to be associated with the
5967 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5968
5969<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5970<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]5971 location. At compile-time, the code generator generates information to allow
5972 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5973 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5974 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5975
5976</div>
5977
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5978<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5979<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5980 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5981</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5982
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5983<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5984
5985<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5986<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5987 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5988</pre>
5989
5990<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5991<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5992 locations, allowing garbage collector implementations that require read
5993 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5994
5995<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5996<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]5997 allocated from the garbage collector. The first object is a pointer to the
5998 start of the referenced object, if needed by the language runtime (otherwise
5999 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6000
6001<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6002<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6003 instruction, but may be replaced with substantially more complex code by the
6004 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6005 may only be used in a function which <a href="#gc">specifies a GC
6006 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6007
6008</div>
6009
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6010<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6011<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6012 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6013</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6014
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6015<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6016
6017<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6018<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6019 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6020</pre>
6021
6022<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6023<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6024 locations, allowing garbage collector implementations that require write
6025 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6026
6027<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6028<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]6029 object to store it to, and the third is the address of the field of Obj to
6030 store to. If the runtime does not require a pointer to the object, Obj may
6031 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6032
6033<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6034<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6035 instruction, but may be replaced with substantially more complex code by the
6036 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6037 may only be used in a function which <a href="#gc">specifies a GC
6038 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6039
6040</div>
6041
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6042</div>
6043
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6044<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6045<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6046 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6047</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6048
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6049<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6050
6051<p>These intrinsics are provided by LLVM to expose special features that may
6052 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6053
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6054<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6055<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6056 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6057</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6058
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6059<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6060
6061<h5>Syntax:</h5>
6062<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6063 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6064</pre>
6065
6066<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6067<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6068 target-specific value indicating the return address of the current function
6069 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6070
6071<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6072<p>The argument to this intrinsic indicates which function to return the address
6073 for. Zero indicates the calling function, one indicates its caller, etc.
6074 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6075
6076<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6077<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6078 indicating the return address of the specified call frame, or zero if it
6079 cannot be identified. The value returned by this intrinsic is likely to be
6080 incorrect or 0 for arguments other than zero, so it should only be used for
6081 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6082
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6083<p>Note that calling this intrinsic does not prevent function inlining or other
6084 aggressive transformations, so the value returned may not be that of the
6085 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6086
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6087</div>
6088
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6089<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6090<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6091 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6092</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6093
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6094<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6095
6096<h5>Syntax:</h5>
6097<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6098 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6099</pre>
6100
6101<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6102<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6103 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6104
6105<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6106<p>The argument to this intrinsic indicates which function to return the frame
6107 pointer for. Zero indicates the calling function, one indicates its caller,
6108 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6109
6110<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6111<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6112 indicating the frame address of the specified call frame, or zero if it
6113 cannot be identified. The value returned by this intrinsic is likely to be
6114 incorrect or 0 for arguments other than zero, so it should only be used for
6115 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6116
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6117<p>Note that calling this intrinsic does not prevent function inlining or other
6118 aggressive transformations, so the value returned may not be that of the
6119 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6120
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6121</div>
6122
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6123<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6124<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6125 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6126</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6127
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6128<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6129
6130<h5>Syntax:</h5>
6131<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6132 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6133</pre>
6134
6135<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6136<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6137 of the function stack, for use
6138 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6139 useful for implementing language features like scoped automatic variable
6140 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6141
6142<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6143<p>This intrinsic returns a opaque pointer value that can be passed
6144 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6145 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6146 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6147 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6148 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6149 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6150
6151</div>
6152
6153<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6154<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6155 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6156</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6157
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6158<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6159
6160<h5>Syntax:</h5>
6161<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6162 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6163</pre>
6164
6165<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6166<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6167 the function stack to the state it was in when the
6168 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6169 executed. This is useful for implementing language features like scoped
6170 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6171
6172<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6173<p>See the description
6174 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6175
6176</div>
6177
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6178<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6179<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6180 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6181</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6182
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6183<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6184
6185<h5>Syntax:</h5>
6186<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6187 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]6188</pre>
6189
6190<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6191<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6192 insert a prefetch instruction if supported; otherwise, it is a noop.
6193 Prefetches have no effect on the behavior of the program but can change its
6194 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6195
6196<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6197<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6198 specifier determining if the fetch should be for a read (0) or write (1),
6199 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6200 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6201 specifies whether the prefetch is performed on the data (1) or instruction (0)
6202 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6203 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6204
6205<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6206<p>This intrinsic does not modify the behavior of the program. In particular,
6207 prefetches cannot trap and do not produce a value. On targets that support
6208 this intrinsic, the prefetch can provide hints to the processor cache for
6209 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6210
6211</div>
6212
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6213<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6214<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6215 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6216</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6217
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6218<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6219
6220<h5>Syntax:</h5>
6221<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6222 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6223</pre>
6224
6225<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6226<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6227 Counter (PC) in a region of code to simulators and other tools. The method
6228 is target specific, but it is expected that the marker will use exported
6229 symbols to transmit the PC of the marker. The marker makes no guarantees
6230 that it will remain with any specific instruction after optimizations. It is
6231 possible that the presence of a marker will inhibit optimizations. The
6232 intended use is to be inserted after optimizations to allow correlations of
6233 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6234
6235<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6236<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6237
6238<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6239<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6240 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6241
6242</div>
6243
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6244<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6245<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6246 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6247</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6248
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6249<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6250
6251<h5>Syntax:</h5>
6252<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6253 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6254</pre>
6255
6256<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6257<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6258 counter register (or similar low latency, high accuracy clocks) on those
6259 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6260 should map to RPCC. As the backing counters overflow quickly (on the order
6261 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6262
6263<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6264<p>When directly supported, reading the cycle counter should not modify any
6265 memory. Implementations are allowed to either return a application specific
6266 value or a system wide value. On backends without support, this is lowered
6267 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6268
6269</div>
6270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6271</div>
6272
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6273<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6274<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6275 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6276</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6277
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6278<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6279
6280<p>LLVM provides intrinsics for a few important standard C library functions.
6281 These intrinsics allow source-language front-ends to pass information about
6282 the alignment of the pointer arguments to the code generator, providing
6283 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6284
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6285<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6286<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6287 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6288</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6289
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6290<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6291
6292<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6293<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]6294 integer bit width and for different address spaces. Not all targets support
6295 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6296
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6297<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6298 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]6299 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6300 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]6301 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6302</pre>
6303
6304<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6305<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6306 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6307
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6308<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6309 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6310 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6311
6312<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6313
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6314<p>The first argument is a pointer to the destination, the second is a pointer
6315 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6316 number of bytes to copy, the fourth argument is the alignment of the
6317 source and destination locations, and the fifth is a boolean indicating a
6318 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6319
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6320<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]6321 then the caller guarantees that both the source and destination pointers are
6322 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6323
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6324<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6325 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6326 The detailed access behavior is not very cleanly specified and it is unwise
6327 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6328
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6329<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6330
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6331<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6332 source location to the destination location, which are not allowed to
6333 overlap. It copies "len" bytes of memory over. If the argument is known to
6334 be aligned to some boundary, this can be specified as the fourth argument,
6335 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6336
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6337</div>
6338
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6339<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6340<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6341 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6342</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6343
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6344<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6345
6346<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6347<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]6348 width and for different address space. Not all targets support all bit
6349 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6350
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6351<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6352 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]6353 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6354 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]6355 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6356</pre>
6357
6358<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6359<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6360 source location to the destination location. It is similar to the
6361 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6362 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6363
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6364<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6365 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6366 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6367
6368<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6369
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6370<p>The first argument is a pointer to the destination, the second is a pointer
6371 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6372 number of bytes to copy, the fourth argument is the alignment of the
6373 source and destination locations, and the fifth is a boolean indicating a
6374 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6375
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6376<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]6377 then the caller guarantees that the source and destination pointers are
6378 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6379
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6380<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6381 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6382 The detailed access behavior is not very cleanly specified and it is unwise
6383 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6384
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6385<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6386
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6387<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6388 source location to the destination location, which may overlap. It copies
6389 "len" bytes of memory over. If the argument is known to be aligned to some
6390 boundary, this can be specified as the fourth argument, otherwise it should
6391 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6392
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6393</div>
6394
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6395<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6396<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6397 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6398</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6399
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6400<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6401
6402<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6403<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]6404 width and for different address spaces. However, not all targets support all
6405 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6406
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6407<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6408 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6409 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6410 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6411 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6412</pre>
6413
6414<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6415<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6416 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6417
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6418<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6419 intrinsic does not return a value and takes extra alignment/volatile
6420 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6421
6422<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6423<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]6424 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6425 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6426 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6427
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6428<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]6429 then the caller guarantees that the destination pointer is aligned to that
6430 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6431
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6432<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6433 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6434 The detailed access behavior is not very cleanly specified and it is unwise
6435 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6436
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6437<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6438<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6439 at the destination location. If the argument is known to be aligned to some
6440 boundary, this can be specified as the fourth argument, otherwise it should
6441 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6442
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6443</div>
6444
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6445<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6446<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6447 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6448</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6449
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6450<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6451
6452<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6453<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6454 floating point or vector of floating point type. Not all targets support all
6455 types however.</p>
6456
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6457<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6458 declare float @llvm.sqrt.f32(float %Val)
6459 declare double @llvm.sqrt.f64(double %Val)
6460 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6461 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6462 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6463</pre>
6464
6465<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6466<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6467 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6468 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6469 behavior for negative numbers other than -0.0 (which allows for better
6470 optimization, because there is no need to worry about errno being
6471 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]6472
6473<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6474<p>The argument and return value are floating point numbers of the same
6475 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6476
6477<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6478<p>This function returns the sqrt of the specified operand if it is a
6479 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6480
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6481</div>
6482
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6483<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6484<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6485 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6486</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6487
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6488<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6489
6490<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6491<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6492 floating point or vector of floating point type. Not all targets support all
6493 types however.</p>
6494
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6495<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6496 declare float @llvm.powi.f32(float %Val, i32 %power)
6497 declare double @llvm.powi.f64(double %Val, i32 %power)
6498 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6499 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6500 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6501</pre>
6502
6503<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6504<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6505 specified (positive or negative) power. The order of evaluation of
6506 multiplications is not defined. When a vector of floating point type is
6507 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6508
6509<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6510<p>The second argument is an integer power, and the first is a value to raise to
6511 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6512
6513<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6514<p>This function returns the first value raised to the second power with an
6515 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6516
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6517</div>
6518
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6519<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6520<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6521 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6522</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6523
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6524<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6525
6526<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6527<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6528 floating point or vector of floating point type. Not all targets support all
6529 types however.</p>
6530
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6531<pre>
6532 declare float @llvm.sin.f32(float %Val)
6533 declare double @llvm.sin.f64(double %Val)
6534 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6535 declare fp128 @llvm.sin.f128(fp128 %Val)
6536 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6537</pre>
6538
6539<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6540<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6541
6542<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6543<p>The argument and return value are floating point numbers of the same
6544 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6545
6546<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6547<p>This function returns the sine of the specified operand, returning the same
6548 values as the libm <tt>sin</tt> functions would, and handles error conditions
6549 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6550
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6551</div>
6552
6553<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6554<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6555 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6556</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6557
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6558<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6559
6560<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6561<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6562 floating point or vector of floating point type. Not all targets support all
6563 types however.</p>
6564
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6565<pre>
6566 declare float @llvm.cos.f32(float %Val)
6567 declare double @llvm.cos.f64(double %Val)
6568 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6569 declare fp128 @llvm.cos.f128(fp128 %Val)
6570 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6571</pre>
6572
6573<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6574<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6575
6576<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6577<p>The argument and return value are floating point numbers of the same
6578 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6579
6580<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6581<p>This function returns the cosine of the specified operand, returning the same
6582 values as the libm <tt>cos</tt> functions would, and handles error conditions
6583 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6584
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6585</div>
6586
6587<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6588<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6589 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6590</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6591
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6592<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6593
6594<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6595<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6596 floating point or vector of floating point type. Not all targets support all
6597 types however.</p>
6598
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6599<pre>
6600 declare float @llvm.pow.f32(float %Val, float %Power)
6601 declare double @llvm.pow.f64(double %Val, double %Power)
6602 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6603 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6604 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6605</pre>
6606
6607<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6608<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6609 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6610
6611<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6612<p>The second argument is a floating point power, and the first is a value to
6613 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6614
6615<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6616<p>This function returns the first value raised to the second power, returning
6617 the same values as the libm <tt>pow</tt> functions would, and handles error
6618 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6619
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6620</div>
6621
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6622</div>
6623
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6624<!-- _______________________________________________________________________ -->
6625<h4>
6626 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6627</h4>
6628
6629<div>
6630
6631<h5>Syntax:</h5>
6632<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6633 floating point or vector of floating point type. Not all targets support all
6634 types however.</p>
6635
6636<pre>
6637 declare float @llvm.exp.f32(float %Val)
6638 declare double @llvm.exp.f64(double %Val)
6639 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6640 declare fp128 @llvm.exp.f128(fp128 %Val)
6641 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6642</pre>
6643
6644<h5>Overview:</h5>
6645<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6646
6647<h5>Arguments:</h5>
6648<p>The argument and return value are floating point numbers of the same
6649 type.</p>
6650
6651<h5>Semantics:</h5>
6652<p>This function returns the same values as the libm <tt>exp</tt> functions
6653 would, and handles error conditions in the same way.</p>
6654
6655</div>
6656
6657<!-- _______________________________________________________________________ -->
6658<h4>
6659 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6660</h4>
6661
6662<div>
6663
6664<h5>Syntax:</h5>
6665<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6666 floating point or vector of floating point type. Not all targets support all
6667 types however.</p>
6668
6669<pre>
6670 declare float @llvm.log.f32(float %Val)
6671 declare double @llvm.log.f64(double %Val)
6672 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6673 declare fp128 @llvm.log.f128(fp128 %Val)
6674 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6675</pre>
6676
6677<h5>Overview:</h5>
6678<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6679
6680<h5>Arguments:</h5>
6681<p>The argument and return value are floating point numbers of the same
6682 type.</p>
6683
6684<h5>Semantics:</h5>
6685<p>This function returns the same values as the libm <tt>log</tt> functions
6686 would, and handles error conditions in the same way.</p>
6687
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6688<h4>
6689 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6690</h4>
6691
6692<div>
6693
6694<h5>Syntax:</h5>
6695<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6696 floating point or vector of floating point type. Not all targets support all
6697 types however.</p>
6698
6699<pre>
6700 declare float @llvm.fma.f32(float %a, float %b, float %c)
6701 declare double @llvm.fma.f64(double %a, double %b, double %c)
6702 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6703 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6704 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6705</pre>
6706
6707<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]6708<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6709 operation.</p>
6710
6711<h5>Arguments:</h5>
6712<p>The argument and return value are floating point numbers of the same
6713 type.</p>
6714
6715<h5>Semantics:</h5>
6716<p>This function returns the same values as the libm <tt>fma</tt> functions
6717 would.</p>
6718
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6719</div>
6720
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6721<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6722<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6723 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6724</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6725
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6726<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6727
6728<p>LLVM provides intrinsics for a few important bit manipulation operations.
6729 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6730
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6731<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6732<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6733 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6734</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6735
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6736<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6737
6738<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6739<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6740 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6741
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6742<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6743 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6744 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6745 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6746</pre>
6747
6748<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6749<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6750 values with an even number of bytes (positive multiple of 16 bits). These
6751 are useful for performing operations on data that is not in the target's
6752 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6753
6754<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6755<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6756 and low byte of the input i16 swapped. Similarly,
6757 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6758 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6759 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6760 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6761 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6762 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6763
6764</div>
6765
6766<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6767<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6768 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6769</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6770
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6771<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6772
6773<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6774<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]6775 width, or on any vector with integer elements. Not all targets support all
6776 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6777
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6778<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6779 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6780 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6781 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6782 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6783 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6784 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]6785</pre>
6786
6787<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6788<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6789 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6790
6791<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6792<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]6793 integer type, or a vector with integer elements.
6794 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6795
6796<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6797<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6798 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6799
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6800</div>
6801
6802<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6803<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6804 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6805</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6806
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6807<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6808
6809<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6810<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]6811 integer bit width, or any vector whose elements are integers. Not all
6812 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6813
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6814<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6815 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6816 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6817 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6818 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6819 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6820 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]6821</pre>
6822
6823<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6824<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6825 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6826
6827<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6828<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]6829 integer type, or any vector type with integer element type.
6830 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6831
6832<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6833<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6834 zeros in a variable, or within each element of the vector if the operation
6835 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]6836 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6837
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6838</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6839
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6840<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6841<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6842 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6843</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6844
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6845<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6846
6847<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6848<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]6849 integer bit width, or any vector of integer elements. Not all targets
6850 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6851
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6852<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6853 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6854 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6855 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6856 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6857 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6858 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]6859</pre>
6860
6861<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6862<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6863 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6864
6865<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6866<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]6867 integer type, or a vectory with integer element type.. The return type
6868 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6869
6870<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6871<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6872 zeros in a variable, or within each element of a vector.
6873 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6874 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6875
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6876</div>
6877
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6878</div>
6879
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6880<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6881<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6882 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6883</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6884
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6885<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6886
6887<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6888
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6889<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6890<h4>
6891 <a name="int_sadd_overflow">
6892 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6893 </a>
6894</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6895
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6896<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6897
6898<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6899<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]6900 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6901
6902<pre>
6903 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6904 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6905 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6906</pre>
6907
6908<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6909<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6910 a signed addition of the two arguments, and indicate whether an overflow
6911 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6912
6913<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6914<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]6915 be of integer types of any bit width, but they must have the same bit
6916 width. The second element of the result structure must be of
6917 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6918 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6919
6920<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6921<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6922 a signed addition of the two variables. They return a structure &mdash; the
6923 first element of which is the signed summation, and the second element of
6924 which is a bit specifying if the signed summation resulted in an
6925 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6926
6927<h5>Examples:</h5>
6928<pre>
6929 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6930 %sum = extractvalue {i32, i1} %res, 0
6931 %obit = extractvalue {i32, i1} %res, 1
6932 br i1 %obit, label %overflow, label %normal
6933</pre>
6934
6935</div>
6936
6937<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6938<h4>
6939 <a name="int_uadd_overflow">
6940 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6941 </a>
6942</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6943
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6944<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6945
6946<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6947<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]6948 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6949
6950<pre>
6951 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6952 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6953 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6954</pre>
6955
6956<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6957<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6958 an unsigned addition of the two arguments, and indicate whether a carry
6959 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6960
6961<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6962<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]6963 be of integer types of any bit width, but they must have the same bit
6964 width. The second element of the result structure must be of
6965 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6966 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6967
6968<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6969<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6970 an unsigned addition of the two arguments. They return a structure &mdash;
6971 the first element of which is the sum, and the second element of which is a
6972 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6973
6974<h5>Examples:</h5>
6975<pre>
6976 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6977 %sum = extractvalue {i32, i1} %res, 0
6978 %obit = extractvalue {i32, i1} %res, 1
6979 br i1 %obit, label %carry, label %normal
6980</pre>
6981
6982</div>
6983
6984<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6985<h4>
6986 <a name="int_ssub_overflow">
6987 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6988 </a>
6989</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6990
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6991<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6992
6993<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6994<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]6995 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6996
6997<pre>
6998 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6999 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7000 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7001</pre>
7002
7003<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7004<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7005 a signed subtraction of the two arguments, and indicate whether an overflow
7006 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7007
7008<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7009<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]7010 be of integer types of any bit width, but they must have the same bit
7011 width. The second element of the result structure must be of
7012 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7013 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7014
7015<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7016<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7017 a signed subtraction of the two arguments. They return a structure &mdash;
7018 the first element of which is the subtraction, and the second element of
7019 which is a bit specifying if the signed subtraction resulted in an
7020 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7021
7022<h5>Examples:</h5>
7023<pre>
7024 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7025 %sum = extractvalue {i32, i1} %res, 0
7026 %obit = extractvalue {i32, i1} %res, 1
7027 br i1 %obit, label %overflow, label %normal
7028</pre>
7029
7030</div>
7031
7032<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7033<h4>
7034 <a name="int_usub_overflow">
7035 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7036 </a>
7037</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7038
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7039<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7040
7041<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7042<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]7043 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7044
7045<pre>
7046 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7047 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7048 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7049</pre>
7050
7051<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7052<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7053 an unsigned subtraction of the two arguments, and indicate whether an
7054 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7055
7056<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7057<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]7058 be of integer types of any bit width, but they must have the same bit
7059 width. The second element of the result structure must be of
7060 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7061 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7062
7063<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7064<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7065 an unsigned subtraction of the two arguments. They return a structure &mdash;
7066 the first element of which is the subtraction, and the second element of
7067 which is a bit specifying if the unsigned subtraction resulted in an
7068 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7069
7070<h5>Examples:</h5>
7071<pre>
7072 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7073 %sum = extractvalue {i32, i1} %res, 0
7074 %obit = extractvalue {i32, i1} %res, 1
7075 br i1 %obit, label %overflow, label %normal
7076</pre>
7077
7078</div>
7079
7080<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7081<h4>
7082 <a name="int_smul_overflow">
7083 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7084 </a>
7085</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7086
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7087<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7088
7089<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7090<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]7091 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7092
7093<pre>
7094 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7095 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7096 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7097</pre>
7098
7099<h5>Overview:</h5>
7100
7101<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7102 a signed multiplication of the two arguments, and indicate whether an
7103 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7104
7105<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7106<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]7107 be of integer types of any bit width, but they must have the same bit
7108 width. The second element of the result structure must be of
7109 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7110 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7111
7112<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7113<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7114 a signed multiplication of the two arguments. They return a structure &mdash;
7115 the first element of which is the multiplication, and the second element of
7116 which is a bit specifying if the signed multiplication resulted in an
7117 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7118
7119<h5>Examples:</h5>
7120<pre>
7121 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7122 %sum = extractvalue {i32, i1} %res, 0
7123 %obit = extractvalue {i32, i1} %res, 1
7124 br i1 %obit, label %overflow, label %normal
7125</pre>
7126
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7127</div>
7128
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7129<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7130<h4>
7131 <a name="int_umul_overflow">
7132 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7133 </a>
7134</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7135
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7136<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7137
7138<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7139<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]7140 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7141
7142<pre>
7143 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7144 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7145 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7146</pre>
7147
7148<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7149<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7150 a unsigned multiplication of the two arguments, and indicate whether an
7151 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7152
7153<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7154<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]7155 be of integer types of any bit width, but they must have the same bit
7156 width. The second element of the result structure must be of
7157 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7158 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7159
7160<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7161<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7162 an unsigned multiplication of the two arguments. They return a structure
7163 &mdash; the first element of which is the multiplication, and the second
7164 element of which is a bit specifying if the unsigned multiplication resulted
7165 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7166
7167<h5>Examples:</h5>
7168<pre>
7169 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7170 %sum = extractvalue {i32, i1} %res, 0
7171 %obit = extractvalue {i32, i1} %res, 1
7172 br i1 %obit, label %overflow, label %normal
7173</pre>
7174
7175</div>
7176
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7177</div>
7178
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7179<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7180<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7181 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7182</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7183
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7184<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7185
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7186<p>Half precision floating point is a storage-only format. This means that it is
7187 a dense encoding (in memory) but does not support computation in the
7188 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7189
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7190<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7191 value as an i16, then convert it to float with <a
7192 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7193 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7194 double etc). To store the value back to memory, it is first converted to
7195 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7196 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7197 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7198
7199<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7200<h4>
7201 <a name="int_convert_to_fp16">
7202 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7203 </a>
7204</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7205
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7206<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7207
7208<h5>Syntax:</h5>
7209<pre>
7210 declare i16 @llvm.convert.to.fp16(f32 %a)
7211</pre>
7212
7213<h5>Overview:</h5>
7214<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7215 a conversion from single precision floating point format to half precision
7216 floating point format.</p>
7217
7218<h5>Arguments:</h5>
7219<p>The intrinsic function contains single argument - the value to be
7220 converted.</p>
7221
7222<h5>Semantics:</h5>
7223<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7224 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7225 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7226 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7227
7228<h5>Examples:</h5>
7229<pre>
7230 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7231 store i16 %res, i16* @x, align 2
7232</pre>
7233
7234</div>
7235
7236<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7237<h4>
7238 <a name="int_convert_from_fp16">
7239 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7240 </a>
7241</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7242
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7243<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7244
7245<h5>Syntax:</h5>
7246<pre>
7247 declare f32 @llvm.convert.from.fp16(i16 %a)
7248</pre>
7249
7250<h5>Overview:</h5>
7251<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7252 a conversion from half precision floating point format to single precision
7253 floating point format.</p>
7254
7255<h5>Arguments:</h5>
7256<p>The intrinsic function contains single argument - the value to be
7257 converted.</p>
7258
7259<h5>Semantics:</h5>
7260<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7261 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7262 precision floating point format. The input half-float value is represented by
7263 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7264
7265<h5>Examples:</h5>
7266<pre>
7267 %a = load i16* @x, align 2
7268 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7269</pre>
7270
7271</div>
7272
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7273</div>
7274
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7275<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7276<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7277 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7278</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7279
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7280<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7281
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7282<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7283 prefix), are described in
7284 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7285 Level Debugging</a> document.</p>
7286
7287</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7288
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7289<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7290<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7291 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7292</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7293
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7294<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7295
7296<p>The LLVM exception handling intrinsics (which all start with
7297 <tt>llvm.eh.</tt> prefix), are described in
7298 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7299 Handling</a> document.</p>
7300
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7301</div>
7302
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7303<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7304<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7305 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7306</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7307
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7308<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7309
7310<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7311 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7312 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7313 function pointer lacking the nest parameter - the caller does not need to
7314 provide a value for it. Instead, the value to use is stored in advance in a
7315 "trampoline", a block of memory usually allocated on the stack, which also
7316 contains code to splice the nest value into the argument list. This is used
7317 to implement the GCC nested function address extension.</p>
7318
7319<p>For example, if the function is
7320 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7321 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7322 follows:</p>
7323
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7324<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7325 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7326 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7327 %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]7328 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7329</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7330
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7331<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7332 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7333
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7334<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7335<h4>
7336 <a name="int_it">
7337 '<tt>llvm.init.trampoline</tt>' Intrinsic
7338 </a>
7339</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7340
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7341<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7342
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7343<h5>Syntax:</h5>
7344<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7345 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]7346</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7347
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7348<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7349<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7350 function pointer suitable for executing it.</p>
7351
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7352<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7353<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7354 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7355 sufficiently aligned block of memory; this memory is written to by the
7356 intrinsic. Note that the size and the alignment are target-specific - LLVM
7357 currently provides no portable way of determining them, so a front-end that
7358 generates this intrinsic needs to have some target-specific knowledge.
7359 The <tt>func</tt> argument must hold a function bitcast to
7360 an <tt>i8*</tt>.</p>
7361
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7362<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7363<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7364 dependent code, turning it into a function. A pointer to this function is
7365 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7366 function pointer type</a> before being called. The new function's signature
7367 is the same as that of <tt>func</tt> with any arguments marked with
7368 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7369 is allowed, and it must be of pointer type. Calling the new function is
7370 equivalent to calling <tt>func</tt> with the same argument list, but
7371 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7372 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7373 by <tt>tramp</tt> is modified, then the effect of any later call to the
7374 returned function pointer is undefined.</p>
7375
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7376</div>
7377
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7378</div>
7379
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7380<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7381<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7382 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7383</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7384
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7385<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7386
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7387<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7388 hardware constructs for atomic operations and memory synchronization. This
7389 provides an interface to the hardware, not an interface to the programmer. It
7390 is aimed at a low enough level to allow any programming models or APIs
7391 (Application Programming Interfaces) which need atomic behaviors to map
7392 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7393 hardware provides a "universal IR" for source languages, it also provides a
7394 starting point for developing a "universal" atomic operation and
7395 synchronization IR.</p>
7396
7397<p>These do <em>not</em> form an API such as high-level threading libraries,
7398 software transaction memory systems, atomic primitives, and intrinsic
7399 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7400 application libraries. The hardware interface provided by LLVM should allow
7401 a clean implementation of all of these APIs and parallel programming models.
7402 No one model or paradigm should be selected above others unless the hardware
7403 itself ubiquitously does so.</p>
7404
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7405<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7406<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7407 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7408</h4>
7409
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7410<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7411<h5>Syntax:</h5>
7412<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7413 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]7414</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7415
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7416<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7417<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7418 specific pairs of memory access types.</p>
7419
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7420<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7421<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7422 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7423 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7424 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7425
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7426<ul>
7427 <li><tt>ll</tt>: load-load barrier</li>
7428 <li><tt>ls</tt>: load-store barrier</li>
7429 <li><tt>sl</tt>: store-load barrier</li>
7430 <li><tt>ss</tt>: store-store barrier</li>
7431 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7432</ul>
7433
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7434<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7435<p>This intrinsic causes the system to enforce some ordering constraints upon
7436 the loads and stores of the program. This barrier does not
7437 indicate <em>when</em> any events will occur, it only enforces
7438 an <em>order</em> in which they occur. For any of the specified pairs of load
7439 and store operations (f.ex. load-load, or store-load), all of the first
7440 operations preceding the barrier will complete before any of the second
7441 operations succeeding the barrier begin. Specifically the semantics for each
7442 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7443
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7444<ul>
7445 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7446 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7447 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7448 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7449 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7450 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7451 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7452 load after the barrier begins.</li>
7453</ul>
7454
7455<p>These semantics are applied with a logical "and" behavior when more than one
7456 is enabled in a single memory barrier intrinsic.</p>
7457
7458<p>Backends may implement stronger barriers than those requested when they do
7459 not support as fine grained a barrier as requested. Some architectures do
7460 not need all types of barriers and on such architectures, these become
7461 noops.</p>
7462
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7463<h5>Example:</h5>
7464<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7465%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7466%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7467 store i32 4, %ptr
7468
7469%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7470 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]7471 <i>; guarantee the above finishes</i>
7472 store i32 8, %ptr <i>; before this begins</i>
7473</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7474
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7475</div>
7476
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7477<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7478<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7479 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7480</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7481
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7482<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7483
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7484<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7485<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7486 any integer bit width and for different address spaces. Not all targets
7487 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7488
7489<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7490 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7491 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7492 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7493 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]7494</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7495
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7496<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7497<p>This loads a value in memory and compares it to a given value. If they are
7498 equal, it stores a new value into the memory.</p>
7499
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7500<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7501<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7502 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7503 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7504 this integer type. While any bit width integer may be used, targets may only
7505 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7506
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7507<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7508<p>This entire intrinsic must be executed atomically. It first loads the value
7509 in memory pointed to by <tt>ptr</tt> and compares it with the
7510 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7511 memory. The loaded value is yielded in all cases. This provides the
7512 equivalent of an atomic compare-and-swap operation within the SSA
7513 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7514
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7515<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7516<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7517%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7518%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7519 store i32 4, %ptr
7520
7521%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7522%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7523 <i>; yields {i32}:result1 = 4</i>
7524%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7525%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7526
7527%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7528%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7529 <i>; yields {i32}:result2 = 8</i>
7530%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7531
7532%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7533</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7534
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7535</div>
7536
7537<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7538<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7539 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7540</h4>
7541
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7542<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7543<h5>Syntax:</h5>
7544
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7545<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7546 integer bit width. Not all targets support all bit widths however.</p>
7547
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7548<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7549 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7550 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7551 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7552 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]7553</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7554
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7555<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7556<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7557 the value from memory. It then stores the value in <tt>val</tt> in the memory
7558 at <tt>ptr</tt>.</p>
7559
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7560<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7561<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7562 the <tt>val</tt> argument and the result must be integers of the same bit
7563 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7564 integer type. The targets may only lower integer representations they
7565 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7566
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7567<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7568<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7569 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7570 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7571
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7572<h5>Examples:</h5>
7573<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7574%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7575%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7576 store i32 4, %ptr
7577
7578%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7579%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7580 <i>; yields {i32}:result1 = 4</i>
7581%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7582%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7583
7584%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7585%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7586 <i>; yields {i32}:result2 = 8</i>
7587
7588%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7589%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7590</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7591
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7592</div>
7593
7594<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7595<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7596 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7597</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7598
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7599<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7600
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7601<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7602<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7603 any integer bit width. Not all targets support all bit widths however.</p>
7604
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7605<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7606 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7607 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7608 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7609 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]7610</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7611
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7612<h5>Overview:</h5>
7613<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7614 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7615
7616<h5>Arguments:</h5>
7617<p>The intrinsic takes two arguments, the first a pointer to an integer value
7618 and the second an integer value. The result is also an integer value. These
7619 integer types can have any bit width, but they must all have the same bit
7620 width. The targets may only lower integer representations they support.</p>
7621
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7622<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7623<p>This intrinsic does a series of operations atomically. It first loads the
7624 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7625 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]7626
7627<h5>Examples:</h5>
7628<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7629%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7630%ptr = bitcast i8* %mallocP to i32*
7631 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7632%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7633 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7634%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7635 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7636%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7637 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7638%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7639</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7640
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7641</div>
7642
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7643<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7644<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7645 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7646</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7647
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7648<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7649
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7650<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7651<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7652 any integer bit width and for different address spaces. Not all targets
7653 support all bit widths however.</p>
7654
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7655<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7656 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7657 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7658 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7659 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]7660</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7661
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7662<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7663<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7664 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7665
7666<h5>Arguments:</h5>
7667<p>The intrinsic takes two arguments, the first a pointer to an integer value
7668 and the second an integer value. The result is also an integer value. These
7669 integer types can have any bit width, but they must all have the same bit
7670 width. The targets may only lower integer representations they support.</p>
7671
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7672<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7673<p>This intrinsic does a series of operations atomically. It first loads the
7674 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7675 result to <tt>ptr</tt>. It yields the original value stored
7676 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7677
7678<h5>Examples:</h5>
7679<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7680%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7681%ptr = bitcast i8* %mallocP to i32*
7682 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7683%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7684 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7685%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7686 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7687%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7688 <i>; yields {i32}:result3 = 2</i>
7689%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7690</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7691
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7692</div>
7693
7694<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7695<h4>
7696 <a name="int_atomic_load_and">
7697 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7698 </a>
7699 <br>
7700 <a name="int_atomic_load_nand">
7701 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7702 </a>
7703 <br>
7704 <a name="int_atomic_load_or">
7705 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7706 </a>
7707 <br>
7708 <a name="int_atomic_load_xor">
7709 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7710 </a>
7711</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7712
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7713<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7714
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7715<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7716<p>These are overloaded intrinsics. You can
7717 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7718 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7719 bit width and for different address spaces. Not all targets support all bit
7720 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7721
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7722<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7723 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7724 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7725 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7726 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]7727</pre>
7728
7729<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7730 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7731 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7732 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7733 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]7734</pre>
7735
7736<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7737 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7738 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7739 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7740 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]7741</pre>
7742
7743<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7744 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7745 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7746 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7747 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]7748</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7749
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7750<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7751<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7752 the value stored in memory at <tt>ptr</tt>. It yields the original value
7753 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7754
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7755<h5>Arguments:</h5>
7756<p>These intrinsics take two arguments, the first a pointer to an integer value
7757 and the second an integer value. The result is also an integer value. These
7758 integer types can have any bit width, but they must all have the same bit
7759 width. The targets may only lower integer representations they support.</p>
7760
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7761<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7762<p>These intrinsics does a series of operations atomically. They first load the
7763 value stored at <tt>ptr</tt>. They then do the bitwise
7764 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7765 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7766
7767<h5>Examples:</h5>
7768<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7769%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7770%ptr = bitcast i8* %mallocP to i32*
7771 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7772%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7773 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7774%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7775 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7776%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7777 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7778%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7779 <i>; yields {i32}:result3 = FF</i>
7780%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7781</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7782
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7783</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7784
7785<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7786<h4>
7787 <a name="int_atomic_load_max">
7788 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7789 </a>
7790 <br>
7791 <a name="int_atomic_load_min">
7792 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7793 </a>
7794 <br>
7795 <a name="int_atomic_load_umax">
7796 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7797 </a>
7798 <br>
7799 <a name="int_atomic_load_umin">
7800 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7801 </a>
7802</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7803
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7804<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7805
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7806<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7807<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7808 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7809 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7810 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7811
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7812<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7813 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7814 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7815 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7816 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]7817</pre>
7818
7819<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7820 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7821 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7822 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7823 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]7824</pre>
7825
7826<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7827 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7828 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7829 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7830 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]7831</pre>
7832
7833<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7834 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7835 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7836 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7837 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]7838</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7839
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7840<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7841<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7842 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7843 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7844
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7845<h5>Arguments:</h5>
7846<p>These intrinsics take two arguments, the first a pointer to an integer value
7847 and the second an integer value. The result is also an integer value. These
7848 integer types can have any bit width, but they must all have the same bit
7849 width. The targets may only lower integer representations they support.</p>
7850
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7851<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7852<p>These intrinsics does a series of operations atomically. They first load the
7853 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7854 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7855 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7856
7857<h5>Examples:</h5>
7858<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7859%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7860%ptr = bitcast i8* %mallocP to i32*
7861 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7862%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7863 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7864%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7865 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7866%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7867 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7868%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7869 <i>; yields {i32}:result3 = 8</i>
7870%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7871</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7872
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7873</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7874
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7875</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7876
7877<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7878<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7879 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7880</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7881
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7882<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7883
7884<p>This class of intrinsics exists to information about the lifetime of memory
7885 objects and ranges where variables are immutable.</p>
7886
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7887<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7888<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7889 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7890</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7891
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7892<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7893
7894<h5>Syntax:</h5>
7895<pre>
7896 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7897</pre>
7898
7899<h5>Overview:</h5>
7900<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7901 object's lifetime.</p>
7902
7903<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7904<p>The first argument is a constant integer representing the size of the
7905 object, or -1 if it is variable sized. The second argument is a pointer to
7906 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7907
7908<h5>Semantics:</h5>
7909<p>This intrinsic indicates that before this point in the code, the value of the
7910 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]7911 never be used and has an undefined value. A load from the pointer that
7912 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7913 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7914
7915</div>
7916
7917<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7918<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7919 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7920</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7921
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7922<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7923
7924<h5>Syntax:</h5>
7925<pre>
7926 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7927</pre>
7928
7929<h5>Overview:</h5>
7930<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7931 object's lifetime.</p>
7932
7933<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7934<p>The first argument is a constant integer representing the size of the
7935 object, or -1 if it is variable sized. The second argument is a pointer to
7936 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7937
7938<h5>Semantics:</h5>
7939<p>This intrinsic indicates that after this point in the code, the value of the
7940 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7941 never be used and has an undefined value. Any stores into the memory object
7942 following this intrinsic may be removed as dead.
7943
7944</div>
7945
7946<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7947<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7948 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7949</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7950
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7951<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7952
7953<h5>Syntax:</h5>
7954<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]7955 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7956</pre>
7957
7958<h5>Overview:</h5>
7959<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7960 a memory object will not change.</p>
7961
7962<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7963<p>The first argument is a constant integer representing the size of the
7964 object, or -1 if it is variable sized. The second argument is a pointer to
7965 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7966
7967<h5>Semantics:</h5>
7968<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7969 the return value, the referenced memory location is constant and
7970 unchanging.</p>
7971
7972</div>
7973
7974<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7975<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7976 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7977</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7978
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7979<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7980
7981<h5>Syntax:</h5>
7982<pre>
7983 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7984</pre>
7985
7986<h5>Overview:</h5>
7987<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7988 a memory object are mutable.</p>
7989
7990<h5>Arguments:</h5>
7991<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7992 The second argument is a constant integer representing the size of the
7993 object, or -1 if it is variable sized and the third argument is a pointer
7994 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7995
7996<h5>Semantics:</h5>
7997<p>This intrinsic indicates that the memory is mutable again.</p>
7998
7999</div>
8000
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8001</div>
8002
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8003<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8004<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8005 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8006</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8007
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8008<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8009
8010<p>This class of intrinsics is designed to be generic and has no specific
8011 purpose.</p>
8012
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8013<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8014<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8015 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8016</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8017
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8018<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8019
8020<h5>Syntax:</h5>
8021<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8022 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]8023</pre>
8024
8025<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8026<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8027
8028<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8029<p>The first argument is a pointer to a value, the second is a pointer to a
8030 global string, the third is a pointer to a global string which is the source
8031 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8032
8033<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8034<p>This intrinsic allows annotation of local variables with arbitrary strings.
8035 This can be useful for special purpose optimizations that want to look for
8036 these annotations. These have no other defined use, they are ignored by code
8037 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8038
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8039</div>
8040
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8041<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8042<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]8043 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8044</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8045
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8046<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8047
8048<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8049<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8050 any integer bit width.</p>
8051
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8052<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8053 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8054 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8055 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8056 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8057 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]8058</pre>
8059
8060<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8061<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8062
8063<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8064<p>The first argument is an integer value (result of some expression), the
8065 second is a pointer to a global string, the third is a pointer to a global
8066 string which is the source file name, and the last argument is the line
8067 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8068
8069<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8070<p>This intrinsic allows annotations to be put on arbitrary expressions with
8071 arbitrary strings. This can be useful for special purpose optimizations that
8072 want to look for these annotations. These have no other defined use, they
8073 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8074
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8075</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8076
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8077<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8078<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8079 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8080</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8081
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8082<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8083
8084<h5>Syntax:</h5>
8085<pre>
8086 declare void @llvm.trap()
8087</pre>
8088
8089<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8090<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8091
8092<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8093<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8094
8095<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8096<p>This intrinsics is lowered to the target dependent trap instruction. If the
8097 target does not have a trap instruction, this intrinsic will be lowered to
8098 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8099
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8100</div>
8101
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8102<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8103<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]8104 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8105</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8106
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8107<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8108
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8109<h5>Syntax:</h5>
8110<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8111 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8112</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8113
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8114<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8115<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8116 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8117 ensure that it is placed on the stack before local variables.</p>
8118
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8119<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8120<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8121 arguments. The first argument is the value loaded from the stack
8122 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8123 that has enough space to hold the value of the guard.</p>
8124
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8125<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8126<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8127 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8128 stack. This is to ensure that if a local variable on the stack is
8129 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8130 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8131 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8132 function.</p>
8133
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8134</div>
8135
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8136<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8137<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8138 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8139</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8140
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8141<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8142
8143<h5>Syntax:</h5>
8144<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8145 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8146 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8147</pre>
8148
8149<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8150<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8151 the optimizers to determine at compile time whether a) an operation (like
8152 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8153 runtime check for overflow isn't necessary. An object in this context means
8154 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8155
8156<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8157<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8158 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8159 is a boolean 0 or 1. This argument determines whether you want the
8160 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]8161 1, variables are not allowed.</p>
8162
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8163<h5>Semantics:</h5>
8164<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8165 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8166 depending on the <tt>type</tt> argument, if the size cannot be determined at
8167 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8168
8169</div>
8170
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8171</div>
8172
8173</div>
8174
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8175<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8176<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8177<address>
8178 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8179 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8180 <a href="http://validator.w3.org/check/referer"><img
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Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8182
8183 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8184 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8185 Last modified: $Date$
8186</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8187
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8188</body>
8189</html>