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gerrit-public.fairphone.software / toolchain / llvm-project / 35b54aa148b1f1cedf67fd303ba5d81cab084519 / . / 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 Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]78 <li><a href="#t_opaque">Opaque Type</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>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]126 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]127 </ol>
128 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]129 <li><a href="#binaryops">Binary Operations</a>
130 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]131 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]132 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]137 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
138 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
139 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]140 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
141 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
142 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]143 </ol>
144 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]145 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
146 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]147 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
148 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
149 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]150 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]151 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 </ol>
154 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]155 <li><a href="#vectorops">Vector Operations</a>
156 <ol>
157 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
158 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
159 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]160 </ol>
161 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]162 <li><a href="#aggregateops">Aggregate Operations</a>
163 <ol>
164 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
165 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
166 </ol>
167 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]168 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]169 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]170 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]171 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
172 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
173 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]174 </ol>
175 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]176 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]177 <ol>
178 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
179 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
180 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]183 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
184 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
185 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
186 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]187 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
188 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]189 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]190 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]191 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]192 <li><a href="#otherops">Other Operations</a>
193 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]194 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
195 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]196 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]197 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]198 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]199 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]200 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]201 </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 Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]204 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]205 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]206 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
207 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]208 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
209 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
210 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]211 </ol>
212 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]213 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
214 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]215 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
216 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
217 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]218 </ol>
219 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]220 <li><a href="#int_codegen">Code Generator Intrinsics</a>
221 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]222 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
223 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
224 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
225 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
226 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
227 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]228 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]229 </ol>
230 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]231 <li><a href="#int_libc">Standard C Library Intrinsics</a>
232 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]233 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]238 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]241 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]243 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]244 </ol>
245 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]246 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]247 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]248 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]249 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
250 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
251 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]252 </ol>
253 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]254 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
255 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]256 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
257 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
260 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]261 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]262 </ol>
263 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]264 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
265 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]266 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
267 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]268 </ol>
269 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]270 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]271 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]272 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]273 <ol>
274 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]275 </ol>
276 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]277 <li><a href="#int_atomics">Atomic intrinsics</a>
278 <ol>
279 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
280 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
281 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
282 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
283 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
284 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
285 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
286 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
287 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
288 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
289 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
290 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
291 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
292 </ol>
293 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]294 <li><a href="#int_memorymarkers">Memory Use Markers</a>
295 <ol>
296 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
297 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
298 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
299 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
300 </ol>
301 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]302 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]303 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]304 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]306 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]307 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]308 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.trap</tt>' Intrinsic</a></li>
310 <li><a href="#int_stackprotector">
311 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]312 <li><a href="#int_objectsize">
313 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]314 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]315 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]316 </ol>
317 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]318</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]319
320<div class="doc_author">
321 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
322 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]323</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]325<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]326<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]328
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]329<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]330
331<p>This document is a reference manual for the LLVM assembly language. LLVM is
332 a Static Single Assignment (SSA) based representation that provides type
333 safety, low-level operations, flexibility, and the capability of representing
334 'all' high-level languages cleanly. It is the common code representation
335 used throughout all phases of the LLVM compilation strategy.</p>
336
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]337</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]338
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]339<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]340<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]341<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]342
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]343<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]344
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]345<p>The LLVM code representation is designed to be used in three different forms:
346 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
347 for fast loading by a Just-In-Time compiler), and as a human readable
348 assembly language representation. This allows LLVM to provide a powerful
349 intermediate representation for efficient compiler transformations and
350 analysis, while providing a natural means to debug and visualize the
351 transformations. The three different forms of LLVM are all equivalent. This
352 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]354<p>The LLVM representation aims to be light-weight and low-level while being
355 expressive, typed, and extensible at the same time. It aims to be a
356 "universal IR" of sorts, by being at a low enough level that high-level ideas
357 may be cleanly mapped to it (similar to how microprocessors are "universal
358 IR's", allowing many source languages to be mapped to them). By providing
359 type information, LLVM can be used as the target of optimizations: for
360 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]361 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]362 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]364<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]365<h4>
366 <a name="wellformed">Well-Formedness</a>
367</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]368
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]369<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]371<p>It is important to note that this document describes 'well formed' LLVM
372 assembly language. There is a difference between what the parser accepts and
373 what is considered 'well formed'. For example, the following instruction is
374 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]376<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]377%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]378</pre>
379
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]380<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
381 LLVM infrastructure provides a verification pass that may be used to verify
382 that an LLVM module is well formed. This pass is automatically run by the
383 parser after parsing input assembly and by the optimizer before it outputs
384 bitcode. The violations pointed out by the verifier pass indicate bugs in
385 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]386
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]387</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]388
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]389</div>
390
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]391<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]392
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]393<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]394<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]395<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]396
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]397<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]398
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]399<p>LLVM identifiers come in two basic types: global and local. Global
400 identifiers (functions, global variables) begin with the <tt>'@'</tt>
401 character. Local identifiers (register names, types) begin with
402 the <tt>'%'</tt> character. Additionally, there are three different formats
403 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]404
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]405<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]406 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]407 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
408 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
409 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
410 other characters in their names can be surrounded with quotes. Special
411 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
412 ASCII code for the character in hexadecimal. In this way, any character
413 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]414
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]415 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]416 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]417
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]418 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]419 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]420</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]422<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]423 don't need to worry about name clashes with reserved words, and the set of
424 reserved words may be expanded in the future without penalty. Additionally,
425 unnamed identifiers allow a compiler to quickly come up with a temporary
426 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]427
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]428<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]429 languages. There are keywords for different opcodes
430 ('<tt><a href="#i_add">add</a></tt>',
431 '<tt><a href="#i_bitcast">bitcast</a></tt>',
432 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
433 ('<tt><a href="#t_void">void</a></tt>',
434 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
435 reserved words cannot conflict with variable names, because none of them
436 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]437
438<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]439 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]440
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]441<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]443<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]444%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]445</pre>
446
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]447<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]449<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]450%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]451</pre>
452
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]453<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]454
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]455<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]456%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
457%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]458%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459</pre>
460
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]461<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
462 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]463
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]464<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]466 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
468 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]469 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]470
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]471 <li>Unnamed temporaries are numbered sequentially</li>
472</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]473
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]474<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]475 demonstrating instructions, we will follow an instruction with a comment that
476 defines the type and name of value produced. Comments are shown in italic
477 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]478
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]479</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]480
481<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]482<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]483<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]484<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]485<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]486<h3>
487 <a name="modulestructure">Module Structure</a>
488</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]490<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]492<p>LLVM programs are composed of "Module"s, each of which is a translation unit
493 of the input programs. Each module consists of functions, global variables,
494 and symbol table entries. Modules may be combined together with the LLVM
495 linker, which merges function (and global variable) definitions, resolves
496 forward declarations, and merges symbol table entries. Here is an example of
497 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]498
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]499<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]500<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]501<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]503<i>; External declaration of the puts function</i>&nbsp;
504<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]505
506<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]507define i32 @main() { <i>; i32()* </i>&nbsp;
508 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
509 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]510
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]511 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
512 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
513 <a href="#i_ret">ret</a> i32 0&nbsp;
514}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]515
516<i>; Named metadata</i>
517!1 = metadata !{i32 41}
518!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]519</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]521<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]522 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]524 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
525 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]527<p>In general, a module is made up of a list of global values, where both
528 functions and global variables are global values. Global values are
529 represented by a pointer to a memory location (in this case, a pointer to an
530 array of char, and a pointer to a function), and have one of the
531 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]532
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]533</div>
534
535<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]536<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]537 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]538</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]539
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]540<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]541
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]542<p>All Global Variables and Functions have one of the following types of
543 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]544
545<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]547 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
548 by objects in the current module. In particular, linking code into a
549 module with an private global value may cause the private to be renamed as
550 necessary to avoid collisions. Because the symbol is private to the
551 module, all references can be updated. This doesn't show up in any symbol
552 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]553
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]555 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
556 assembler and evaluated by the linker. Unlike normal strong symbols, they
557 are removed by the linker from the final linked image (executable or
558 dynamic library).</dd>
559
560 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
561 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
562 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
563 linker. The symbols are removed by the linker from the final linked image
564 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]565
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]566 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
567 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
568 of the object is not taken. For instance, functions that had an inline
569 definition, but the compiler decided not to inline it. Note,
570 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
571 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
572 visibility. The symbols are removed by the linker from the final linked
573 image (executable or dynamic library).</dd>
574
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]575 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]576 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]577 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
578 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]579
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]581 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]582 into the object file corresponding to the LLVM module. They exist to
583 allow inlining and other optimizations to take place given knowledge of
584 the definition of the global, which is known to be somewhere outside the
585 module. Globals with <tt>available_externally</tt> linkage are allowed to
586 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
587 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]588
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]589 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]590 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]591 the same name when linkage occurs. This can be used to implement
592 some forms of inline functions, templates, or other code which must be
593 generated in each translation unit that uses it, but where the body may
594 be overridden with a more definitive definition later. Unreferenced
595 <tt>linkonce</tt> globals are allowed to be discarded. Note that
596 <tt>linkonce</tt> linkage does not actually allow the optimizer to
597 inline the body of this function into callers because it doesn't know if
598 this definition of the function is the definitive definition within the
599 program or whether it will be overridden by a stronger definition.
600 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
601 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]602
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]603 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]604 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
605 <tt>linkonce</tt> linkage, except that unreferenced globals with
606 <tt>weak</tt> linkage may not be discarded. This is used for globals that
607 are declared "weak" in C source code.</dd>
608
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]610 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
611 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
612 global scope.
613 Symbols with "<tt>common</tt>" linkage are merged in the same way as
614 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]615 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]616 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]617 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
618 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]619
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]620
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]621 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]622 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]623 pointer to array type. When two global variables with appending linkage
624 are linked together, the two global arrays are appended together. This is
625 the LLVM, typesafe, equivalent of having the system linker append together
626 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]627
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]628 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]629 <dd>The semantics of this linkage follow the ELF object file model: the symbol
630 is weak until linked, if not linked, the symbol becomes null instead of
631 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]632
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]633 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
634 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]635 <dd>Some languages allow differing globals to be merged, such as two functions
636 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]637 that only equivalent globals are ever merged (the "one definition rule"
638 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]639 and <tt>weak_odr</tt> linkage types to indicate that the global will only
640 be merged with equivalent globals. These linkage types are otherwise the
641 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]642
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]643 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]644 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]645 visible, meaning that it participates in linkage and can be used to
646 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]647</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]648
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]649<p>The next two types of linkage are targeted for Microsoft Windows platform
650 only. They are designed to support importing (exporting) symbols from (to)
651 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]653<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]654 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]655 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]656 or variable via a global pointer to a pointer that is set up by the DLL
657 exporting the symbol. On Microsoft Windows targets, the pointer name is
658 formed by combining <code>__imp_</code> and the function or variable
659 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]660
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]661 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]662 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]663 pointer to a pointer in a DLL, so that it can be referenced with the
664 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
665 name is formed by combining <code>__imp_</code> and the function or
666 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]667</dl>
668
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]669<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
670 another module defined a "<tt>.LC0</tt>" variable and was linked with this
671 one, one of the two would be renamed, preventing a collision. Since
672 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
673 declarations), they are accessible outside of the current module.</p>
674
675<p>It is illegal for a function <i>declaration</i> to have any linkage type
676 other than "externally visible", <tt>dllimport</tt>
677 or <tt>extern_weak</tt>.</p>
678
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]679<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]680 or <tt>weak_odr</tt> linkages.</p>
681
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]682</div>
683
684<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]685<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]686 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]687</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]688
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]689<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]690
691<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]692 and <a href="#i_invoke">invokes</a> can all have an optional calling
693 convention specified for the call. The calling convention of any pair of
694 dynamic caller/callee must match, or the behavior of the program is
695 undefined. The following calling conventions are supported by LLVM, and more
696 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]697
698<dl>
699 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]700 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]701 specified) matches the target C calling conventions. This calling
702 convention supports varargs function calls and tolerates some mismatch in
703 the declared prototype and implemented declaration of the function (as
704 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]705
706 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]708 (e.g. by passing things in registers). This calling convention allows the
709 target to use whatever tricks it wants to produce fast code for the
710 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]711 (Application Binary Interface).
712 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]713 when this or the GHC convention is used.</a> This calling convention
714 does not support varargs and requires the prototype of all callees to
715 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]716
717 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]718 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]719 as possible under the assumption that the call is not commonly executed.
720 As such, these calls often preserve all registers so that the call does
721 not break any live ranges in the caller side. This calling convention
722 does not support varargs and requires the prototype of all callees to
723 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]724
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]725 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
726 <dd>This calling convention has been implemented specifically for use by the
727 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
728 It passes everything in registers, going to extremes to achieve this by
729 disabling callee save registers. This calling convention should not be
730 used lightly but only for specific situations such as an alternative to
731 the <em>register pinning</em> performance technique often used when
732 implementing functional programming languages.At the moment only X86
733 supports this convention and it has the following limitations:
734 <ul>
735 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
736 floating point types are supported.</li>
737 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
738 6 floating point parameters.</li>
739 </ul>
740 This calling convention supports
741 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
742 requires both the caller and callee are using it.
743 </dd>
744
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]745 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]746 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]747 target-specific calling conventions to be used. Target specific calling
748 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]749</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]750
751<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]752 support Pascal conventions or any other well-known target-independent
753 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]754
755</div>
756
757<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]758<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]759 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]760</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]761
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]762<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]764<p>All Global Variables and Functions have one of the following visibility
765 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]766
767<dl>
768 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]769 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]770 that the declaration is visible to other modules and, in shared libraries,
771 means that the declared entity may be overridden. On Darwin, default
772 visibility means that the declaration is visible to other modules. Default
773 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]774
775 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]776 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]777 object if they are in the same shared object. Usually, hidden visibility
778 indicates that the symbol will not be placed into the dynamic symbol
779 table, so no other module (executable or shared library) can reference it
780 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]781
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]782 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]783 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]784 the dynamic symbol table, but that references within the defining module
785 will bind to the local symbol. That is, the symbol cannot be overridden by
786 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]787</dl>
788
789</div>
790
791<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]792<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]793 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]794</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]795
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]796<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]797
798<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]799 it easier to read the IR and make the IR more condensed (particularly when
800 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]801
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]802<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]803%mytype = type { %mytype*, i32 }
804</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]805
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]806<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]807 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]808 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]809
810<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]811 and that you can therefore specify multiple names for the same type. This
812 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
813 uses structural typing, the name is not part of the type. When printing out
814 LLVM IR, the printer will pick <em>one name</em> to render all types of a
815 particular shape. This means that if you have code where two different
816 source types end up having the same LLVM type, that the dumper will sometimes
817 print the "wrong" or unexpected type. This is an important design point and
818 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]819
820</div>
821
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]822<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]823<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]824 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]825</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]826
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]827<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]828
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]829<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]830 instead of run-time. Global variables may optionally be initialized, may
831 have an explicit section to be placed in, and may have an optional explicit
832 alignment specified. A variable may be defined as "thread_local", which
833 means that it will not be shared by threads (each thread will have a
834 separated copy of the variable). A variable may be defined as a global
835 "constant," which indicates that the contents of the variable
836 will <b>never</b> be modified (enabling better optimization, allowing the
837 global data to be placed in the read-only section of an executable, etc).
838 Note that variables that need runtime initialization cannot be marked
839 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]840
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]841<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
842 constant, even if the final definition of the global is not. This capability
843 can be used to enable slightly better optimization of the program, but
844 requires the language definition to guarantee that optimizations based on the
845 'constantness' are valid for the translation units that do not include the
846 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]847
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]848<p>As SSA values, global variables define pointer values that are in scope
849 (i.e. they dominate) all basic blocks in the program. Global variables
850 always define a pointer to their "content" type because they describe a
851 region of memory, and all memory objects in LLVM are accessed through
852 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]853
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]854<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
855 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]856 like this can be merged with other constants if they have the same
857 initializer. Note that a constant with significant address <em>can</em>
858 be merged with a <tt>unnamed_addr</tt> constant, the result being a
859 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]860
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]861<p>A global variable may be declared to reside in a target-specific numbered
862 address space. For targets that support them, address spaces may affect how
863 optimizations are performed and/or what target instructions are used to
864 access the variable. The default address space is zero. The address space
865 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]866
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]867<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]868 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]869
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]870<p>An explicit alignment may be specified for a global, which must be a power
871 of 2. If not present, or if the alignment is set to zero, the alignment of
872 the global is set by the target to whatever it feels convenient. If an
873 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]874 alignment. Targets and optimizers are not allowed to over-align the global
875 if the global has an assigned section. In this case, the extra alignment
876 could be observable: for example, code could assume that the globals are
877 densely packed in their section and try to iterate over them as an array,
878 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]879
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]880<p>For example, the following defines a global in a numbered address space with
881 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]882
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]883<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]884@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]885</pre>
886
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]887</div>
888
889
890<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]891<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]892 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]893</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]894
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]895<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]896
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]897<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]898 optional <a href="#linkage">linkage type</a>, an optional
899 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]900 <a href="#callingconv">calling convention</a>,
901 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]902 <a href="#paramattrs">parameter attribute</a> for the return type, a function
903 name, a (possibly empty) argument list (each with optional
904 <a href="#paramattrs">parameter attributes</a>), optional
905 <a href="#fnattrs">function attributes</a>, an optional section, an optional
906 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
907 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]908
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]909<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
910 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]911 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]912 <a href="#callingconv">calling convention</a>,
913 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]914 <a href="#paramattrs">parameter attribute</a> for the return type, a function
915 name, a possibly empty list of arguments, an optional alignment, and an
916 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]917
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]918<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]919 (Control Flow Graph) for the function. Each basic block may optionally start
920 with a label (giving the basic block a symbol table entry), contains a list
921 of instructions, and ends with a <a href="#terminators">terminator</a>
922 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]923
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]924<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]925 executed on entrance to the function, and it is not allowed to have
926 predecessor basic blocks (i.e. there can not be any branches to the entry
927 block of a function). Because the block can have no predecessors, it also
928 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]929
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]930<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]931 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]932
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]933<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]934 the alignment is set to zero, the alignment of the function is set by the
935 target to whatever it feels convenient. If an explicit alignment is
936 specified, the function is forced to have at least that much alignment. All
937 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]938
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]939<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
940 be significant and two identical functions can be merged</p>.
941
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]942<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]943<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]944define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]945 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
946 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
947 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
948 [<a href="#gc">gc</a>] { ... }
949</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]950
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]951</div>
952
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]953<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]954<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]955 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]956</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]957
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]958<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]959
960<p>Aliases act as "second name" for the aliasee value (which can be either
961 function, global variable, another alias or bitcast of global value). Aliases
962 may have an optional <a href="#linkage">linkage type</a>, and an
963 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]964
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]965<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]966<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]967@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]968</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]969
970</div>
971
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]972<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]973<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]974 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]975</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]976
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]977<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]978
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]979<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]980 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]981 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]982
983<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]984<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]985; Some unnamed metadata nodes, which are referenced by the named metadata.
986!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]987!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]988!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]989; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]990!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]991</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]992
993</div>
994
995<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]996<h3>
997 <a name="paramattrs">Parameter Attributes</a>
998</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]999
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1000<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1001
1002<p>The return type and each parameter of a function type may have a set of
1003 <i>parameter attributes</i> associated with them. Parameter attributes are
1004 used to communicate additional information about the result or parameters of
1005 a function. Parameter attributes are considered to be part of the function,
1006 not of the function type, so functions with different parameter attributes
1007 can have the same function type.</p>
1008
1009<p>Parameter attributes are simple keywords that follow the type specified. If
1010 multiple parameter attributes are needed, they are space separated. For
1011 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1012
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1013<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1014declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1015declare i32 @atoi(i8 zeroext)
1016declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1017</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1018
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1019<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1020 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1021
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1022<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1023
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1024<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1025 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1026 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1027 should be zero-extended to the extent required by the target's ABI (which
1028 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1029 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1030
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1033 should be sign-extended to the extent required by the target's ABI (which
1034 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1035 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1036
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1037 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This indicates that this parameter or return value should be treated in a
1039 special target-dependent fashion during while emitting code for a function
1040 call or return (usually, by putting it in a register as opposed to memory,
1041 though some targets use it to distinguish between two different kinds of
1042 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1043
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1044 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1045 <dd><p>This indicates that the pointer parameter should really be passed by
1046 value to the function. The attribute implies that a hidden copy of the
1047 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1048 is made between the caller and the callee, so the callee is unable to
1049 modify the value in the callee. This attribute is only valid on LLVM
1050 pointer arguments. It is generally used to pass structs and arrays by
1051 value, but is also valid on pointers to scalars. The copy is considered
1052 to belong to the caller not the callee (for example,
1053 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1054 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1055 values.</p>
1056
1057 <p>The byval attribute also supports specifying an alignment with
1058 the align attribute. It indicates the alignment of the stack slot to
1059 form and the known alignment of the pointer specified to the call site. If
1060 the alignment is not specified, then the code generator makes a
1061 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1062
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1063 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1064 <dd>This indicates that the pointer parameter specifies the address of a
1065 structure that is the return value of the function in the source program.
1066 This pointer must be guaranteed by the caller to be valid: loads and
1067 stores to the structure may be assumed by the callee to not to trap. This
1068 may only be applied to the first parameter. This is not a valid attribute
1069 for return values. </dd>
1070
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1071 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1072 <dd>This indicates that pointer values
1073 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1074 value do not alias pointer values which are not <i>based</i> on it,
1075 ignoring certain "irrelevant" dependencies.
1076 For a call to the parent function, dependencies between memory
1077 references from before or after the call and from those during the call
1078 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1079 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1080 The caller shares the responsibility with the callee for ensuring that
1081 these requirements are met.
1082 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1083 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1084<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1085 Note that this definition of <tt>noalias</tt> is intentionally
1086 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1087 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1088<br>
1089 For function return values, C99's <tt>restrict</tt> is not meaningful,
1090 while LLVM's <tt>noalias</tt> is.
1091 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1092
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1093 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1094 <dd>This indicates that the callee does not make any copies of the pointer
1095 that outlive the callee itself. This is not a valid attribute for return
1096 values.</dd>
1097
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1098 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This indicates that the pointer parameter can be excised using the
1100 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1101 attribute for return values.</dd>
1102</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1103
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1104</div>
1105
1106<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1107<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1108 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1109</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1110
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1111<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1112
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1113<p>Each function may specify a garbage collector name, which is simply a
1114 string:</p>
1115
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1116<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1117define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1118</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1119
1120<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1121 collector which will cause the compiler to alter its output in order to
1122 support the named garbage collection algorithm.</p>
1123
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1124</div>
1125
1126<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1127<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1128 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1129</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1130
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1131<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1132
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1133<p>Function attributes are set to communicate additional information about a
1134 function. Function attributes are considered to be part of the function, not
1135 of the function type, so functions with different parameter attributes can
1136 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1137
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1138<p>Function attributes are simple keywords that follow the type specified. If
1139 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1140
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1141<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1142define void @f() noinline { ... }
1143define void @f() alwaysinline { ... }
1144define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1145define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1146</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1147
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1148<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1149 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1150 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1151 the backend should forcibly align the stack pointer. Specify the
1152 desired alignment, which must be a power of two, in parentheses.
1153
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1154 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1155 <dd>This attribute indicates that the inliner should attempt to inline this
1156 function into callers whenever possible, ignoring any active inlining size
1157 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1158
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1159 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1160 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1161 meaning the function can be patched and/or hooked even while it is
1162 loaded into memory. On x86, the function prologue will be preceded
1163 by six bytes of padding and will begin with a two-byte instruction.
1164 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1165 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1166
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1167 <dt><tt><b>nonlazybind</b></tt></dt>
1168 <dd>This attribute suppresses lazy symbol binding for the function. This
1169 may make calls to the function faster, at the cost of extra program
1170 startup time if the function is not called during program startup.</dd>
1171
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1172 <dt><tt><b>inlinehint</b></tt></dt>
1173 <dd>This attribute indicates that the source code contained a hint that inlining
1174 this function is desirable (such as the "inline" keyword in C/C++). It
1175 is just a hint; it imposes no requirements on the inliner.</dd>
1176
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1177 <dt><tt><b>naked</b></tt></dt>
1178 <dd>This attribute disables prologue / epilogue emission for the function.
1179 This can have very system-specific consequences.</dd>
1180
1181 <dt><tt><b>noimplicitfloat</b></tt></dt>
1182 <dd>This attributes disables implicit floating point instructions.</dd>
1183
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1184 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1185 <dd>This attribute indicates that the inliner should never inline this
1186 function in any situation. This attribute may not be used together with
1187 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1188
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1189 <dt><tt><b>noredzone</b></tt></dt>
1190 <dd>This attribute indicates that the code generator should not use a red
1191 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1192
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1193 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1194 <dd>This function attribute indicates that the function never returns
1195 normally. This produces undefined behavior at runtime if the function
1196 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1197
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This function attribute indicates that the function never returns with an
1200 unwind or exceptional control flow. If the function does unwind, its
1201 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1202
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1203 <dt><tt><b>optsize</b></tt></dt>
1204 <dd>This attribute suggests that optimization passes and code generator passes
1205 make choices that keep the code size of this function low, and otherwise
1206 do optimizations specifically to reduce code size.</dd>
1207
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1208 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1209 <dd>This attribute indicates that the function computes its result (or decides
1210 to unwind an exception) based strictly on its arguments, without
1211 dereferencing any pointer arguments or otherwise accessing any mutable
1212 state (e.g. memory, control registers, etc) visible to caller functions.
1213 It does not write through any pointer arguments
1214 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1215 changes any state visible to callers. This means that it cannot unwind
1216 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1217 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1218
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1219 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1220 <dd>This attribute indicates that the function does not write through any
1221 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1222 arguments) or otherwise modify any state (e.g. memory, control registers,
1223 etc) visible to caller functions. It may dereference pointer arguments
1224 and read state that may be set in the caller. A readonly function always
1225 returns the same value (or unwinds an exception identically) when called
1226 with the same set of arguments and global state. It cannot unwind an
1227 exception by calling the <tt>C++</tt> exception throwing methods, but may
1228 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1229
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1230 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1231 <dd>This attribute indicates that the function should emit a stack smashing
1232 protector. It is in the form of a "canary"&mdash;a random value placed on
1233 the stack before the local variables that's checked upon return from the
1234 function to see if it has been overwritten. A heuristic is used to
1235 determine if a function needs stack protectors or not.<br>
1236<br>
1237 If a function that has an <tt>ssp</tt> attribute is inlined into a
1238 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1239 function will have an <tt>ssp</tt> attribute.</dd>
1240
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1241 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1242 <dd>This attribute indicates that the function should <em>always</em> emit a
1243 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1244 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1245<br>
1246 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1247 function that doesn't have an <tt>sspreq</tt> attribute or which has
1248 an <tt>ssp</tt> attribute, then the resulting function will have
1249 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1250</dl>
1251
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1252</div>
1253
1254<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1255<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1256 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1257</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1258
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1259<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1260
1261<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1262 the GCC "file scope inline asm" blocks. These blocks are internally
1263 concatenated by LLVM and treated as a single unit, but may be separated in
1264 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1265
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1266<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1267module asm "inline asm code goes here"
1268module asm "more can go here"
1269</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1270
1271<p>The strings can contain any character by escaping non-printable characters.
1272 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]1273 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1274
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1275<p>The inline asm code is simply printed to the machine code .s file when
1276 assembly code is generated.</p>
1277
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1278</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1279
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1280<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1281<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1282 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1283</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1284
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1285<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1286
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1287<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1288 data is to be laid out in memory. The syntax for the data layout is
1289 simply:</p>
1290
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1291<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1292target datalayout = "<i>layout specification</i>"
1293</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1294
1295<p>The <i>layout specification</i> consists of a list of specifications
1296 separated by the minus sign character ('-'). Each specification starts with
1297 a letter and may include other information after the letter to define some
1298 aspect of the data layout. The specifications accepted are as follows:</p>
1299
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1300<dl>
1301 <dt><tt>E</tt></dt>
1302 <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]1303 bits with the most significance have the lowest address location.</dd>
1304
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1305 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1306 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1307 the bits with the least significance have the lowest address
1308 location.</dd>
1309
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1310 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1311 <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]1312 <i>preferred</i> alignments. All sizes are in bits. Specifying
1313 the <i>pref</i> alignment is optional. If omitted, the
1314 preceding <tt>:</tt> should be omitted too.</dd>
1315
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1316 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1317 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1318 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1319
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1320 <dt><tt>v<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 alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1322 <i>size</i>.</dd>
1323
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1324 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1325 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1326 <i>size</i>. Only values of <i>size</i> that are supported by the target
1327 will work. 32 (float) and 64 (double) are supported on all targets;
1328 80 or 128 (different flavors of long double) are also supported on some
1329 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1330
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1331 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1332 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1333 <i>size</i>.</dd>
1334
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1335 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1336 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1337 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1338
1339 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1340 <dd>This specifies a set of native integer widths for the target CPU
1341 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1342 "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]1343 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1344 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1345</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1346
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1347<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1348 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1349 specifications in the <tt>datalayout</tt> keyword. The default specifications
1350 are given in this list:</p>
1351
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1352<ul>
1353 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1354 <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]1355 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1356 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1357 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1358 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1359 <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]1360 alignment of 64-bits</li>
1361 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1362 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1363 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1364 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1365 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1366 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1367</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1368
1369<p>When LLVM is determining the alignment for a given type, it uses the
1370 following rules:</p>
1371
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1372<ol>
1373 <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]1374 specification is used.</li>
1375
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1376 <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]1377 smallest integer type that is larger than the bitwidth of the sought type
1378 is used. If none of the specifications are larger than the bitwidth then
1379 the the largest integer type is used. For example, given the default
1380 specifications above, the i7 type will use the alignment of i8 (next
1381 largest) while both i65 and i256 will use the alignment of i64 (largest
1382 specified).</li>
1383
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1384 <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]1385 largest vector type that is smaller than the sought vector type will be
1386 used as a fall back. This happens because &lt;128 x double&gt; can be
1387 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1388</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1389
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1390</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1391
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1392<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1393<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1394 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1395</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1396
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1397<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1398
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1399<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1400with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1401is undefined. Pointer values are associated with address ranges
1402according to the following rules:</p>
1403
1404<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1405 <li>A pointer value is associated with the addresses associated with
1406 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1407 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1408 range of the variable's storage.</li>
1409 <li>The result value of an allocation instruction is associated with
1410 the address range of the allocated storage.</li>
1411 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1412 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1413 <li>An integer constant other than zero or a pointer value returned
1414 from a function not defined within LLVM may be associated with address
1415 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1416 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1417 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1418</ul>
1419
1420<p>A pointer value is <i>based</i> on another pointer value according
1421 to the following rules:</p>
1422
1423<ul>
1424 <li>A pointer value formed from a
1425 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1426 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1427 <li>The result value of a
1428 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1429 of the <tt>bitcast</tt>.</li>
1430 <li>A pointer value formed by an
1431 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1432 pointer values that contribute (directly or indirectly) to the
1433 computation of the pointer's value.</li>
1434 <li>The "<i>based</i> on" relationship is transitive.</li>
1435</ul>
1436
1437<p>Note that this definition of <i>"based"</i> is intentionally
1438 similar to the definition of <i>"based"</i> in C99, though it is
1439 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1440
1441<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1442<tt><a href="#i_load">load</a></tt> merely indicates the size and
1443alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1444interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1445<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1446and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1447
1448<p>Consequently, type-based alias analysis, aka TBAA, aka
1449<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1450LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1451additional information which specialized optimization passes may use
1452to implement type-based alias analysis.</p>
1453
1454</div>
1455
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1456<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1457<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1458 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1459</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1460
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1461<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1462
1463<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1464href="#i_store"><tt>store</tt></a>s, and <a
1465href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1466The optimizers must not change the number of volatile operations or change their
1467order of execution relative to other volatile operations. The optimizers
1468<i>may</i> change the order of volatile operations relative to non-volatile
1469operations. This is not Java's "volatile" and has no cross-thread
1470synchronization behavior.</p>
1471
1472</div>
1473
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame^]1474<!-- ======================================================================= -->
1475<h3>
1476 <a name="memmodel">Memory Model for Concurrent Operations</a>
1477</h3>
1478
1479<div>
1480
1481<p>The LLVM IR does not define any way to start parallel threads of execution
1482or to register signal handlers. Nonetheless, there are platform-specific
1483ways to create them, and we define LLVM IR's behavior in their presence. This
1484model is inspired by the C++0x memory model.</p>
1485
1486<p>We define a <i>happens-before</i> partial order as the least partial order
1487that</p>
1488<ul>
1489 <li>Is a superset of single-thread program order, and</li>
1490 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1491 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1492 by platform-specific techniques, like pthread locks, thread
1493 creation, thread joining, etc., and by the atomic operations described
1494 in the <a href="#int_atomics">Atomic intrinsics</a> section.</li>
1495</ul>
1496
1497<p>Note that program order does not introduce <i>happens-before</i> edges
1498between a thread and signals executing inside that thread.</p>
1499
1500<p>Every (defined) read operation (load instructions, memcpy, atomic
1501loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1502(defined) write operations (store instructions, atomic
1503stores/read-modify-writes, memcpy, etc.). For each byte, <var>R</var> reads the
1504value written by some write that it <i>may see</i>, given any relevant
1505<i>happens-before</i> constraints. <var>R<sub>byte</sub></var> may
1506see any write to the same byte, except:</p>
1507
1508<ul>
1509 <li>If <var>write<sub>1</sub></var> happens before
1510 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1511 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
1512 must not see <var>write<sub>1</sub></var>.
1513 <li>If <var>R<sub>byte</sub></var> happens before <var>write<sub>3</var>,
1514 then <var>R<sub>byte</sub></var> must not see
1515 <var>write<sub>3</sub></var>.
1516</ul>
1517
1518<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1519<ul>
1520 <li>If there is no write to the same byte that happens before
1521 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1522 <tt>undef</tt> for that byte.
1523 <li>If <var>R<sub>byte</sub></var> may see exactly one write,
1524 <var>R<sub>byte</sub></var> returns the value written by that
1525 write.</li>
1526 <li>If <var>R<sub>byte</sub></var> and all the writes it may see are
1527 atomic, it chooses one of those writes and returns it value.
1528 Given any two bytes in a given read <var>R</var>, if the set of
1529 writes <var>R<sub>byte</sub></var> may see is the same as the set
1530 of writes another byte may see, they will both choose the same write.
1531 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1532</ul>
1533
1534<p><var>R</var> returns the value composed of the series of bytes it read.
1535This implies that some bytes within the value may be <tt>undef</tt>
1536<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1537defines the semantics of the operation; it doesn't mean that targets will
1538emit more than one instruction to read the series of bytes.</p>
1539
1540<p>Note that in cases where none of the atomic intrinsics are used, this model
1541places only one restriction on IR transformations on top of what is required
1542for single-threaded execution: introducing a store to a byte which might not
1543otherwise be stored to can introduce undefined behavior.</p>
1544
1545<!-- FIXME: This model assumes all targets where concurrency is relevant have
1546a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1547none of the backends currently in the tree fall into this category; however,
1548there might be targets which care. If there are, we want a paragraph
1549like the following:
1550
1551Targets may specify that stores narrower than a certain width are not
1552available; on such a target, for the purposes of this model, treat any
1553non-atomic write with an alignment or width less than the minimum width
1554as if it writes to the relevant surrounding bytes.
1555-->
1556
1557</div>
1558
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1559</div>
1560
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1561<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1562<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1563<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1564
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1565<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1566
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1567<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1568 intermediate representation. Being typed enables a number of optimizations
1569 to be performed on the intermediate representation directly, without having
1570 to do extra analyses on the side before the transformation. A strong type
1571 system makes it easier to read the generated code and enables novel analyses
1572 and transformations that are not feasible to perform on normal three address
1573 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1574
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1575<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1576<h3>
1577 <a name="t_classifications">Type Classifications</a>
1578</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1579
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1580<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1581
1582<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1583
1584<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1585 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1586 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1587 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1588 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1589 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1590 </tr>
1591 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1592 <td><a href="#t_floating">floating point</a></td>
1593 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1594 </tr>
1595 <tr>
1596 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1597 <td><a href="#t_integer">integer</a>,
1598 <a href="#t_floating">floating point</a>,
1599 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1600 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1601 <a href="#t_struct">structure</a>,
1602 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1603 <a href="#t_label">label</a>,
1604 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1605 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1606 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1607 <tr>
1608 <td><a href="#t_primitive">primitive</a></td>
1609 <td><a href="#t_label">label</a>,
1610 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1611 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1612 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1613 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1614 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1615 </tr>
1616 <tr>
1617 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1618 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1619 <a href="#t_function">function</a>,
1620 <a href="#t_pointer">pointer</a>,
1621 <a href="#t_struct">structure</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1622 <a href="#t_vector">vector</a>,
1623 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1624 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1625 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1626 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1627</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1628
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1629<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1630 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1631 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1632
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1633</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1634
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1635<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1636<h3>
1637 <a name="t_primitive">Primitive Types</a>
1638</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1639
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1640<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1641
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1642<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1643 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1644
1645<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1646<h4>
1647 <a name="t_integer">Integer Type</a>
1648</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1649
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1650<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1651
1652<h5>Overview:</h5>
1653<p>The integer type is a very simple type that simply specifies an arbitrary
1654 bit width for the integer type desired. Any bit width from 1 bit to
1655 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1656
1657<h5>Syntax:</h5>
1658<pre>
1659 iN
1660</pre>
1661
1662<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1663 value.</p>
1664
1665<h5>Examples:</h5>
1666<table class="layout">
1667 <tr class="layout">
1668 <td class="left"><tt>i1</tt></td>
1669 <td class="left">a single-bit integer.</td>
1670 </tr>
1671 <tr class="layout">
1672 <td class="left"><tt>i32</tt></td>
1673 <td class="left">a 32-bit integer.</td>
1674 </tr>
1675 <tr class="layout">
1676 <td class="left"><tt>i1942652</tt></td>
1677 <td class="left">a really big integer of over 1 million bits.</td>
1678 </tr>
1679</table>
1680
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1681</div>
1682
1683<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1684<h4>
1685 <a name="t_floating">Floating Point Types</a>
1686</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1687
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1688<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1689
1690<table>
1691 <tbody>
1692 <tr><th>Type</th><th>Description</th></tr>
1693 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1694 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1695 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1696 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1697 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1698 </tbody>
1699</table>
1700
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1701</div>
1702
1703<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1704<h4>
1705 <a name="t_x86mmx">X86mmx Type</a>
1706</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1707
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1708<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1709
1710<h5>Overview:</h5>
1711<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>
1712
1713<h5>Syntax:</h5>
1714<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1715 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1716</pre>
1717
1718</div>
1719
1720<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1721<h4>
1722 <a name="t_void">Void Type</a>
1723</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1724
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1725<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1726
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1727<h5>Overview:</h5>
1728<p>The void type does not represent any value and has no size.</p>
1729
1730<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1731<pre>
1732 void
1733</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1734
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1735</div>
1736
1737<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1738<h4>
1739 <a name="t_label">Label Type</a>
1740</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1741
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1742<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1743
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1744<h5>Overview:</h5>
1745<p>The label type represents code labels.</p>
1746
1747<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1748<pre>
1749 label
1750</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1751
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1752</div>
1753
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1754<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1755<h4>
1756 <a name="t_metadata">Metadata Type</a>
1757</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1758
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1759<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1760
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1761<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1762<p>The metadata type represents embedded metadata. No derived types may be
1763 created from metadata except for <a href="#t_function">function</a>
1764 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1765
1766<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1767<pre>
1768 metadata
1769</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1770
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1771</div>
1772
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1773</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1774
1775<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1776<h3>
1777 <a name="t_derived">Derived Types</a>
1778</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1779
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1780<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1781
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1782<p>The real power in LLVM comes from the derived types in the system. This is
1783 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1784 useful types. Each of these types contain one or more element types which
1785 may be a primitive type, or another derived type. For example, it is
1786 possible to have a two dimensional array, using an array as the element type
1787 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1788
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1789</div>
1790
1791
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1792<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1793<h4>
1794 <a name="t_aggregate">Aggregate Types</a>
1795</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1796
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1797<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1798
1799<p>Aggregate Types are a subset of derived types that can contain multiple
1800 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1801 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1802 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1803
1804</div>
1805
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1806<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1807<h4>
1808 <a name="t_array">Array Type</a>
1809</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1810
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1811<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1812
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1813<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1814<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1815 sequentially in memory. The array type requires a size (number of elements)
1816 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1817
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1818<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1819<pre>
1820 [&lt;# elements&gt; x &lt;elementtype&gt;]
1821</pre>
1822
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1823<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1824 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1825
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1826<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1827<table class="layout">
1828 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1829 <td class="left"><tt>[40 x i32]</tt></td>
1830 <td class="left">Array of 40 32-bit integer values.</td>
1831 </tr>
1832 <tr class="layout">
1833 <td class="left"><tt>[41 x i32]</tt></td>
1834 <td class="left">Array of 41 32-bit integer values.</td>
1835 </tr>
1836 <tr class="layout">
1837 <td class="left"><tt>[4 x i8]</tt></td>
1838 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1839 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1840</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1841<p>Here are some examples of multidimensional arrays:</p>
1842<table class="layout">
1843 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1844 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1845 <td class="left">3x4 array of 32-bit integer values.</td>
1846 </tr>
1847 <tr class="layout">
1848 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1849 <td class="left">12x10 array of single precision floating point values.</td>
1850 </tr>
1851 <tr class="layout">
1852 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1853 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1854 </tr>
1855</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1856
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1857<p>There is no restriction on indexing beyond the end of the array implied by
1858 a static type (though there are restrictions on indexing beyond the bounds
1859 of an allocated object in some cases). This means that single-dimension
1860 'variable sized array' addressing can be implemented in LLVM with a zero
1861 length array type. An implementation of 'pascal style arrays' in LLVM could
1862 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1863
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1864</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1865
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1866<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1867<h4>
1868 <a name="t_function">Function Type</a>
1869</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1870
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1871<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1872
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1873<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1874<p>The function type can be thought of as a function signature. It consists of
1875 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]1876 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1877
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1878<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1879<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1880 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1881</pre>
1882
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1883<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]1884 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1885 which indicates that the function takes a variable number of arguments.
1886 Variable argument functions can access their arguments with
1887 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1888 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1889 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1890
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1891<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1892<table class="layout">
1893 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1894 <td class="left"><tt>i32 (i32)</tt></td>
1895 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1896 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1897 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1898 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1899 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1900 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1901 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1902 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1903 </td>
1904 </tr><tr class="layout">
1905 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1906 <td class="left">A vararg function that takes at least one
1907 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1908 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1909 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1910 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1911 </tr><tr class="layout">
1912 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1913 <td class="left">A function taking an <tt>i32</tt>, returning a
1914 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1915 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1916 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1917</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1918
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1919</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1920
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1921<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1922<h4>
1923 <a name="t_struct">Structure Type</a>
1924</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1925
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1926<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1927
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1928<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1929<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1930 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]1931
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1932<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1933 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1934 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1935 Structures in registers are accessed using the
1936 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1937 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1938
1939<p>Structures may optionally be "packed" structures, which indicate that the
1940 alignment of the struct is one byte, and that there is no padding between
1941 the elements. In non-packed structs, padding between field types is defined
1942 by the target data string to match the underlying processor.</p>
1943
1944<p>Structures can either be "anonymous" or "named". An anonymous structure is
1945 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
1946 are always defined at the top level with a name. Anonmyous types are uniqued
1947 by their contents and can never be recursive since there is no way to write
1948 one. Named types can be recursive.
1949</p>
1950
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1951<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1952<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1953 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
1954 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1955</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1956
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1957<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1958<table class="layout">
1959 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1960 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1961 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1962 </tr>
1963 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1964 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1965 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1966 second element is a <a href="#t_pointer">pointer</a> to a
1967 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1968 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1969 </tr>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1970 <tr class="layout">
1971 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
1972 <td class="left">A packed struct known to be 5 bytes in size.</td>
1973 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1974</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1975
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1976</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1977
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1978<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1979<h4>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1980 <a name="t_opaque">Opaque Type</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1981</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1982
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1983<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1984
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1985<h5>Overview:</h5>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1986<p>Opaque types are used to represent named structure types that do not have a
1987 body specified. This corresponds (for example) to the C notion of a forward
1988 declared structure.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1989
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1990<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1991<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1992 %X = type opaque
1993 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1994</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1995
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1996<h5>Examples:</h5>
1997<table class="layout">
1998 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1999 <td class="left"><tt>opaque</tt></td>
2000 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2001 </tr>
2002</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2003
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2004</div>
2005
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2006
2007
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2008<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2009<h4>
2010 <a name="t_pointer">Pointer Type</a>
2011</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2012
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2013<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2014
2015<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]2016<p>The pointer type is used to specify memory locations.
2017 Pointers are commonly used to reference objects in memory.</p>
2018
2019<p>Pointer types may have an optional address space attribute defining the
2020 numbered address space where the pointed-to object resides. The default
2021 address space is number zero. The semantics of non-zero address
2022 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2023
2024<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2025 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2026
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2027<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2028<pre>
2029 &lt;type&gt; *
2030</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2031
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2032<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2033<table class="layout">
2034 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2035 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2036 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2037 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2038 </tr>
2039 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]2040 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2041 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2042 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2043 <tt>i32</tt>.</td>
2044 </tr>
2045 <tr class="layout">
2046 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2047 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2048 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2049 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2050</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2051
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2052</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2053
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2054<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2055<h4>
2056 <a name="t_vector">Vector Type</a>
2057</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2058
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2059<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2060
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2061<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2062<p>A vector type is a simple derived type that represents a vector of elements.
2063 Vector types are used when multiple primitive data are operated in parallel
2064 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]2065 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2066 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2067
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2068<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2069<pre>
2070 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2071</pre>
2072
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]2073<p>The number of elements is a constant integer value larger than 0; elementtype
2074 may be any integer or floating point type. Vectors of size zero are not
2075 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2076
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2077<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2078<table class="layout">
2079 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2080 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2081 <td class="left">Vector of 4 32-bit integer values.</td>
2082 </tr>
2083 <tr class="layout">
2084 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2085 <td class="left">Vector of 8 32-bit floating-point values.</td>
2086 </tr>
2087 <tr class="layout">
2088 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2089 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2090 </tr>
2091</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2092
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2093</div>
2094
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2095<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2096<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2097<!-- *********************************************************************** -->
2098
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2099<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2100
2101<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2102 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2103
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2104<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2105<h3>
2106 <a name="simpleconstants">Simple Constants</a>
2107</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2108
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2109<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2110
2111<dl>
2112 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2113 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2114 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2115
2116 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2117 <dd>Standard integers (such as '4') are constants of
2118 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2119 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2120
2121 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2122 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2123 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2124 notation (see below). The assembler requires the exact decimal value of a
2125 floating-point constant. For example, the assembler accepts 1.25 but
2126 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2127 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2128
2129 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2130 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2131 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2132</dl>
2133
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2134<p>The one non-intuitive notation for constants is the hexadecimal form of
2135 floating point constants. For example, the form '<tt>double
2136 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2137 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2138 constants are required (and the only time that they are generated by the
2139 disassembler) is when a floating point constant must be emitted but it cannot
2140 be represented as a decimal floating point number in a reasonable number of
2141 digits. For example, NaN's, infinities, and other special values are
2142 represented in their IEEE hexadecimal format so that assembly and disassembly
2143 do not cause any bits to change in the constants.</p>
2144
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2145<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2146 represented using the 16-digit form shown above (which matches the IEEE754
2147 representation for double); float values must, however, be exactly
2148 representable as IEE754 single precision. Hexadecimal format is always used
2149 for long double, and there are three forms of long double. The 80-bit format
2150 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2151 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2152 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2153 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2154 currently supported target uses this format. Long doubles will only work if
2155 they match the long double format on your target. All hexadecimal formats
2156 are big-endian (sign bit at the left).</p>
2157
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2158<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2159</div>
2160
2161<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2162<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2163<a name="aggregateconstants"></a> <!-- old anchor -->
2164<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2165</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2166
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2167<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2168
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2169<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2170 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2171
2172<dl>
2173 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2174 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2175 type definitions (a comma separated list of elements, surrounded by braces
2176 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2177 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2178 Structure constants must have <a href="#t_struct">structure type</a>, and
2179 the number and types of elements must match those specified by the
2180 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2181
2182 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2183 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2184 definitions (a comma separated list of elements, surrounded by square
2185 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2186 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2187 the number and types of elements must match those specified by the
2188 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2189
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2190 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2191 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2192 definitions (a comma separated list of elements, surrounded by
2193 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2194 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2195 have <a href="#t_vector">vector type</a>, and the number and types of
2196 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2197
2198 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2199 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2200 value to zero of <em>any</em> type, including scalar and
2201 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2202 This is often used to avoid having to print large zero initializers
2203 (e.g. for large arrays) and is always exactly equivalent to using explicit
2204 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2205
2206 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2207 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2208 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2209 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2210 be interpreted as part of the instruction stream, metadata is a place to
2211 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2212</dl>
2213
2214</div>
2215
2216<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2217<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2218 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2219</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2220
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2221<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2222
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2223<p>The addresses of <a href="#globalvars">global variables</a>
2224 and <a href="#functionstructure">functions</a> are always implicitly valid
2225 (link-time) constants. These constants are explicitly referenced when
2226 the <a href="#identifiers">identifier for the global</a> is used and always
2227 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2228 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2229
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2230<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2231@X = global i32 17
2232@Y = global i32 42
2233@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2234</pre>
2235
2236</div>
2237
2238<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2239<h3>
2240 <a name="undefvalues">Undefined Values</a>
2241</h3>
2242
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2243<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2244
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2245<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]2246 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2247 Undefined values may be of any type (other than '<tt>label</tt>'
2248 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2249
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2250<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2251 program is well defined no matter what value is used. This gives the
2252 compiler more freedom to optimize. Here are some examples of (potentially
2253 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2254
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2255
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2256<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2257 %A = add %X, undef
2258 %B = sub %X, undef
2259 %C = xor %X, undef
2260Safe:
2261 %A = undef
2262 %B = undef
2263 %C = undef
2264</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2265
2266<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]2267 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]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 = or %X, undef
2271 %B = and %X, undef
2272Safe:
2273 %A = -1
2274 %B = 0
2275Unsafe:
2276 %A = undef
2277 %B = undef
2278</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2279
2280<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2281 For example, if <tt>%X</tt> has a zero bit, then the output of the
2282 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2283 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2284 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2285 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2286 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2287 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2288 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2289
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2290<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2291 %A = select undef, %X, %Y
2292 %B = select undef, 42, %Y
2293 %C = select %X, %Y, undef
2294Safe:
2295 %A = %X (or %Y)
2296 %B = 42 (or %Y)
2297 %C = %Y
2298Unsafe:
2299 %A = undef
2300 %B = undef
2301 %C = undef
2302</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2303
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2304<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2305 branch) conditions can go <em>either way</em>, but they have to come from one
2306 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2307 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2308 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2309 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2310 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2311 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2312
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2313<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2314 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2315
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2316 %B = undef
2317 %C = xor %B, %B
2318
2319 %D = undef
2320 %E = icmp lt %D, 4
2321 %F = icmp gte %D, 4
2322
2323Safe:
2324 %A = undef
2325 %B = undef
2326 %C = undef
2327 %D = undef
2328 %E = undef
2329 %F = undef
2330</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2331
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2332<p>This example points out that two '<tt>undef</tt>' operands are not
2333 necessarily the same. This can be surprising to people (and also matches C
2334 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2335 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2336 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2337 its value over its "live range". This is true because the variable doesn't
2338 actually <em>have a live range</em>. Instead, the value is logically read
2339 from arbitrary registers that happen to be around when needed, so the value
2340 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2341 need to have the same semantics or the core LLVM "replace all uses with"
2342 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2343
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2344<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2345 %A = fdiv undef, %X
2346 %B = fdiv %X, undef
2347Safe:
2348 %A = undef
2349b: unreachable
2350</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2351
2352<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2353 value</em> and <em>undefined behavior</em>. An undefined value (like
2354 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2355 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2356 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2357 defined on SNaN's. However, in the second example, we can make a more
2358 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2359 arbitrary value, we are allowed to assume that it could be zero. Since a
2360 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2361 the operation does not execute at all. This allows us to delete the divide and
2362 all code after it. Because the undefined operation "can't happen", the
2363 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2364
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2365<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2366a: store undef -> %X
2367b: store %X -> undef
2368Safe:
2369a: &lt;deleted&gt;
2370b: unreachable
2371</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2372
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2373<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2374 undefined value can be assumed to not have any effect; we can assume that the
2375 value is overwritten with bits that happen to match what was already there.
2376 However, a store <em>to</em> an undefined location could clobber arbitrary
2377 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2378
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2379</div>
2380
2381<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2382<h3>
2383 <a name="trapvalues">Trap Values</a>
2384</h3>
2385
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2386<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2387
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2388<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2389 instead of representing an unspecified bit pattern, they represent the
2390 fact that an instruction or constant expression which cannot evoke side
2391 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2392 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2393
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2394<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]2395 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2396 <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]2397
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2398<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2399
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2400<ul>
2401<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2402 their operands.</li>
2403
2404<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2405 to their dynamic predecessor basic block.</li>
2406
2407<li>Function arguments depend on the corresponding actual argument values in
2408 the dynamic callers of their functions.</li>
2409
2410<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2411 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2412 control back to them.</li>
2413
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2414<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2415 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2416 or exception-throwing call instructions that dynamically transfer control
2417 back to them.</li>
2418
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2419<li>Non-volatile loads and stores depend on the most recent stores to all of the
2420 referenced memory addresses, following the order in the IR
2421 (including loads and stores implied by intrinsics such as
2422 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2423
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2424<!-- TODO: In the case of multiple threads, this only applies if the store
2425 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2426
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2427<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2428
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2429<li>An instruction with externally visible side effects depends on the most
2430 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2431 the order in the IR. (This includes
2432 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2433
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2434<li>An instruction <i>control-depends</i> on a
2435 <a href="#terminators">terminator instruction</a>
2436 if the terminator instruction has multiple successors and the instruction
2437 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2438 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2439
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2440<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2441 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2442 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2443 successor.</li>
2444
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2445<li>Dependence is transitive.</li>
2446
2447</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2448
2449<p>Whenever a trap value is generated, all values which depend on it evaluate
2450 to trap. If they have side effects, the evoke their side effects as if each
2451 operand with a trap value were undef. If they have externally-visible side
2452 effects, the behavior is undefined.</p>
2453
2454<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2455
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2456<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2457entry:
2458 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2459 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2460 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2461 store i32 0, i32* %trap_yet_again ; undefined behavior
2462
2463 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2464 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2465
2466 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2467
2468 %narrowaddr = bitcast i32* @g to i16*
2469 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2470 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2471 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2472
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2473 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2474 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2475
2476true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2477 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2478 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2479 br label %end
2480
2481end:
2482 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2483 ; Both edges into this PHI are
2484 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2485 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2486
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2487 volatile store i32 0, i32* @g ; This would depend on the store in %true
2488 ; if %cmp is true, or the store in %entry
2489 ; otherwise, so this is undefined behavior.
2490
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2491 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2492 ; The same branch again, but this time the
2493 ; true block doesn't have side effects.
2494
2495second_true:
2496 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2497 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2498
2499second_end:
2500 volatile store i32 0, i32* @g ; This time, the instruction always depends
2501 ; on the store in %end. Also, it is
2502 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2503 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2504 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2505</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2506
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2507</div>
2508
2509<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2510<h3>
2511 <a name="blockaddress">Addresses of Basic Blocks</a>
2512</h3>
2513
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2514<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2515
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2516<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2517
2518<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2519 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2520 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2521
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2522<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2523 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2524 comparisons against null. Pointer equality tests between labels addresses
2525 results in undefined behavior &mdash; though, again, comparison against null
2526 is ok, and no label is equal to the null pointer. This may be passed around
2527 as an opaque pointer sized value as long as the bits are not inspected. This
2528 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2529 long as the original value is reconstituted before the <tt>indirectbr</tt>
2530 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2531
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2532<p>Finally, some targets may provide defined semantics when using the value as
2533 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2534
2535</div>
2536
2537
2538<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2539<h3>
2540 <a name="constantexprs">Constant Expressions</a>
2541</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2542
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2543<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2544
2545<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2546 to be used as constants. Constant expressions may be of
2547 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2548 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2549 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2550
2551<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2552 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2553 <dd>Truncate a constant to another type. The bit size of CST must be larger
2554 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2555
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2556 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2557 <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]2558 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2559
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2560 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2561 <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]2562 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2563
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2564 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2565 <dd>Truncate a floating point constant to another floating point type. The
2566 size of CST must be larger than the size of TYPE. Both types must be
2567 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2568
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2569 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2570 <dd>Floating point extend a constant to another type. The size of CST must be
2571 smaller or equal to the size of TYPE. Both types must be floating
2572 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2573
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2574 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2575 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2576 constant. TYPE must be a scalar or vector integer type. CST must be of
2577 scalar or vector floating point type. Both CST and TYPE must be scalars,
2578 or vectors of the same number of elements. If the value won't fit in the
2579 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2580
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2581 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2582 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2583 constant. TYPE must be a scalar or vector integer type. CST must be of
2584 scalar or vector floating point type. Both CST and TYPE must be scalars,
2585 or vectors of the same number of elements. If the value won't fit in the
2586 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2587
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2588 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2589 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2590 constant. TYPE must be a scalar or vector floating point type. CST must be
2591 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2592 vectors of the same number of elements. If the value won't fit in the
2593 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2594
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2595 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2596 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2597 constant. TYPE must be a scalar or vector floating point type. CST must be
2598 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2599 vectors of the same number of elements. If the value won't fit in the
2600 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2601
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2602 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2603 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2604 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2605 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2606 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2607
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2608 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2609 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2610 type. CST must be of integer type. The CST value is zero extended,
2611 truncated, or unchanged to make it fit in a pointer size. This one is
2612 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2613
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2614 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2615 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2616 are the same as those for the <a href="#i_bitcast">bitcast
2617 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2618
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2619 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2620 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2621 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2622 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2623 instruction, the index list may have zero or more indexes, which are
2624 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2625
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2626 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2627 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2628
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2629 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2630 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2631
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2632 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2633 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2634
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2635 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2636 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2637 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2638
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2639 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2640 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2641 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2642
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2643 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2644 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2645 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2646
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2647 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2648 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2649 constants. The index list is interpreted in a similar manner as indices in
2650 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2651 index value must be specified.</dd>
2652
2653 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2654 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2655 constants. The index list is interpreted in a similar manner as indices in
2656 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2657 index value must be specified.</dd>
2658
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2659 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2660 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2661 be any of the <a href="#binaryops">binary</a>
2662 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2663 on operands are the same as those for the corresponding instruction
2664 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2665</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2666
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2667</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2668
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2669</div>
2670
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2671<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2672<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2673<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2674<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2675<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2676<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2677<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2678</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2679
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2680<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2681
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2682<p>LLVM supports inline assembler expressions (as opposed
2683 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2684 a special value. This value represents the inline assembler as a string
2685 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2686 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2687 expression has side effects, and a flag indicating whether the function
2688 containing the asm needs to align its stack conservatively. An example
2689 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2690
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2691<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2692i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2693</pre>
2694
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2695<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2696 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2697 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2698
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2699<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2700%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]2701</pre>
2702
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2703<p>Inline asms with side effects not visible in the constraint list must be
2704 marked as having side effects. This is done through the use of the
2705 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2706
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2707<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2708call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2709</pre>
2710
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2711<p>In some cases inline asms will contain code that will not work unless the
2712 stack is aligned in some way, such as calls or SSE instructions on x86,
2713 yet will not contain code that does that alignment within the asm.
2714 The compiler should make conservative assumptions about what the asm might
2715 contain and should generate its usual stack alignment code in the prologue
2716 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2717
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2718<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2719call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2720</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2721
2722<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2723 first.</p>
2724
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2725<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2726 documented here. Constraints on what can be done (e.g. duplication, moving,
2727 etc need to be documented). This is probably best done by reference to
2728 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2729
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2730<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2731<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2732</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2733
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2734<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2735
2736<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2737 attached to it that contains a list of constant integers. If present, the
2738 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2739 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2740 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2741 source code that produced it. For example:</p>
2742
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2743<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2744call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2745...
2746!42 = !{ i32 1234567 }
2747</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2748
2749<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]2750 IR. If the MDNode contains multiple constants, the code generator will use
2751 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]2752
2753</div>
2754
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2755</div>
2756
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2757<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2758<h3>
2759 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2760</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2761
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2762<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2763
2764<p>LLVM IR allows metadata to be attached to instructions in the program that
2765 can convey extra information about the code to the optimizers and code
2766 generator. One example application of metadata is source-level debug
2767 information. There are two metadata primitives: strings and nodes. All
2768 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2769 preceding exclamation point ('<tt>!</tt>').</p>
2770
2771<p>A metadata string is a string surrounded by double quotes. It can contain
2772 any character by escaping non-printable characters with "\xx" where "xx" is
2773 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2774
2775<p>Metadata nodes are represented with notation similar to structure constants
2776 (a comma separated list of elements, surrounded by braces and preceded by an
2777 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2778 10}</tt>". Metadata nodes can have any values as their operand.</p>
2779
2780<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2781 metadata nodes, which can be looked up in the module symbol table. For
2782 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2783
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2784<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2785 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2786
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2787<div class="doc_code">
2788<pre>
2789call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2790</pre>
2791</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2792
2793<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2794 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2795
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2796<div class="doc_code">
2797<pre>
2798%indvar.next = add i64 %indvar, 1, !dbg !21
2799</pre>
2800</div>
2801
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2802</div>
2803
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2804</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2805
2806<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2807<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2808 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2809</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2810<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2811<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2812<p>LLVM has a number of "magic" global variables that contain data that affect
2813code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2814of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2815section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2816by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2817
2818<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2819<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2820<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2821</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2822
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2823<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2824
2825<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2826href="#linkage_appending">appending linkage</a>. This array contains a list of
2827pointers to global variables and functions which may optionally have a pointer
2828cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2829
2830<pre>
2831 @X = global i8 4
2832 @Y = global i32 123
2833
2834 @llvm.used = appending global [2 x i8*] [
2835 i8* @X,
2836 i8* bitcast (i32* @Y to i8*)
2837 ], section "llvm.metadata"
2838</pre>
2839
2840<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2841compiler, assembler, and linker are required to treat the symbol as if there is
2842a reference to the global that it cannot see. For example, if a variable has
2843internal linkage and no references other than that from the <tt>@llvm.used</tt>
2844list, it cannot be deleted. This is commonly used to represent references from
2845inline asms and other things the compiler cannot "see", and corresponds to
2846"attribute((used))" in GNU C.</p>
2847
2848<p>On some targets, the code generator must emit a directive to the assembler or
2849object file to prevent the assembler and linker from molesting the symbol.</p>
2850
2851</div>
2852
2853<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2854<h3>
2855 <a name="intg_compiler_used">
2856 The '<tt>llvm.compiler.used</tt>' Global Variable
2857 </a>
2858</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2859
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2860<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2861
2862<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2863<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2864touching the symbol. On targets that support it, this allows an intelligent
2865linker to optimize references to the symbol without being impeded as it would be
2866by <tt>@llvm.used</tt>.</p>
2867
2868<p>This is a rare construct that should only be used in rare circumstances, and
2869should not be exposed to source languages.</p>
2870
2871</div>
2872
2873<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2874<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2875<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2876</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2877
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2878<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2879<pre>
2880%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2881@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2882</pre>
2883<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.
2884</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2885
2886</div>
2887
2888<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2889<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2890<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2891</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2892
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2893<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2894<pre>
2895%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2896@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2897</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2898
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2899<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.
2900</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2901
2902</div>
2903
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2904</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2905
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2906<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2907<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2908<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2909
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2910<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2911
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2912<p>The LLVM instruction set consists of several different classifications of
2913 instructions: <a href="#terminators">terminator
2914 instructions</a>, <a href="#binaryops">binary instructions</a>,
2915 <a href="#bitwiseops">bitwise binary instructions</a>,
2916 <a href="#memoryops">memory instructions</a>, and
2917 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2918
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2919<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2920<h3>
2921 <a name="terminators">Terminator Instructions</a>
2922</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2923
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2924<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2925
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2926<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2927 in a program ends with a "Terminator" instruction, which indicates which
2928 block should be executed after the current block is finished. These
2929 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2930 control flow, not values (the one exception being the
2931 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2932
Duncan Sands626b0242010-04-15 20:35:54 +0000[diff] [blame]2933<p>There are seven different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2934 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2935 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2936 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2937 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2938 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2939 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2940 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2941
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2942<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2943<h4>
2944 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2945</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2946
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2947<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2948
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2949<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2950<pre>
2951 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]2952 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2953</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2954
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2955<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2956<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2957 a value) from a function back to the caller.</p>
2958
2959<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2960 value and then causes control flow, and one that just causes control flow to
2961 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2962
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2963<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2964<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2965 return value. The type of the return value must be a
2966 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2967
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2968<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2969 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2970 value or a return value with a type that does not match its type, or if it
2971 has a void return type and contains a '<tt>ret</tt>' instruction with a
2972 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2973
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2974<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2975<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2976 the calling function's context. If the caller is a
2977 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2978 instruction after the call. If the caller was an
2979 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2980 the beginning of the "normal" destination block. If the instruction returns
2981 a value, that value shall set the call or invoke instruction's return
2982 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2983
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2984<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2985<pre>
2986 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2987 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2988 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]2989</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2990
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2991</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2992<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2993<h4>
2994 <a name="i_br">'<tt>br</tt>' Instruction</a>
2995</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2996
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2997<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2998
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2999<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3000<pre>
3001 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3002</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3003
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3004<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3005<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3006 different basic block in the current function. There are two forms of this
3007 instruction, corresponding to a conditional branch and an unconditional
3008 branch.</p>
3009
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3010<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3011<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3012 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3013 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3014 target.</p>
3015
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3016<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3017<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3018 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3019 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3020 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3021
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3022<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3023<pre>
3024Test:
3025 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3026 br i1 %cond, label %IfEqual, label %IfUnequal
3027IfEqual:
3028 <a href="#i_ret">ret</a> i32 1
3029IfUnequal:
3030 <a href="#i_ret">ret</a> i32 0
3031</pre>
3032
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3033</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3034
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3035<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3036<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3037 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3038</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3039
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3040<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3041
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3042<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3043<pre>
3044 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3045</pre>
3046
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3047<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3048<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]3049 several different places. It is a generalization of the '<tt>br</tt>'
3050 instruction, allowing a branch to occur to one of many possible
3051 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3052
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3053<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3054<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3055 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3056 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3057 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3058
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3059<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3060<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3061 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3062 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3063 transferred to the corresponding destination; otherwise, control flow is
3064 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3065
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3066<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3067<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3068 <tt>switch</tt> instruction, this instruction may be code generated in
3069 different ways. For example, it could be generated as a series of chained
3070 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3071
3072<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3073<pre>
3074 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3075 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3076 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3077
3078 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3079 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3080
3081 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3082 switch i32 %val, label %otherwise [ i32 0, label %onzero
3083 i32 1, label %onone
3084 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3085</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3086
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3087</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3088
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3089
3090<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3091<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3092 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3093</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3094
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3095<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3096
3097<h5>Syntax:</h5>
3098<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3099 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]3100</pre>
3101
3102<h5>Overview:</h5>
3103
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3104<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3105 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3106 "<tt>address</tt>". Address must be derived from a <a
3107 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3108
3109<h5>Arguments:</h5>
3110
3111<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3112 rest of the arguments indicate the full set of possible destinations that the
3113 address may point to. Blocks are allowed to occur multiple times in the
3114 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3115
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3116<p>This destination list is required so that dataflow analysis has an accurate
3117 understanding of the CFG.</p>
3118
3119<h5>Semantics:</h5>
3120
3121<p>Control transfers to the block specified in the address argument. All
3122 possible destination blocks must be listed in the label list, otherwise this
3123 instruction has undefined behavior. This implies that jumps to labels
3124 defined in other functions have undefined behavior as well.</p>
3125
3126<h5>Implementation:</h5>
3127
3128<p>This is typically implemented with a jump through a register.</p>
3129
3130<h5>Example:</h5>
3131<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3132 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3133</pre>
3134
3135</div>
3136
3137
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3138<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3139<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3140 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3141</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3142
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3143<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3144
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3145<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3146<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3147 &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]3148 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3149</pre>
3150
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3151<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3152<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3153 function, with the possibility of control flow transfer to either the
3154 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3155 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3156 control flow will return to the "normal" label. If the callee (or any
3157 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3158 instruction, control is interrupted and continued at the dynamically nearest
3159 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3160
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3161<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3162<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3163
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3164<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3165 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3166 convention</a> the call should use. If none is specified, the call
3167 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3168
3169 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3170 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3171 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3172
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3173 <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]3174 function value being invoked. In most cases, this is a direct function
3175 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3176 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3177
3178 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3179 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3180
3181 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3182 signature argument types and parameter attributes. All arguments must be
3183 of <a href="#t_firstclass">first class</a> type. If the function
3184 signature indicates the function accepts a variable number of arguments,
3185 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3186
3187 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3188 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3189
3190 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3191 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3192
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3193 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3194 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3195 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3196</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3197
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3198<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3199<p>This instruction is designed to operate as a standard
3200 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3201 primary difference is that it establishes an association with a label, which
3202 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3203
3204<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3205 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3206 exception. Additionally, this is important for implementation of
3207 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3208
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3209<p>For the purposes of the SSA form, the definition of the value returned by the
3210 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3211 block to the "normal" label. If the callee unwinds then no return value is
3212 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3213
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3214<p>Note that the code generator does not yet completely support unwind, and
3215that the invoke/unwind semantics are likely to change in future versions.</p>
3216
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3217<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3218<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3219 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3220 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3221 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3222 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3223</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3224
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3225</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3226
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3227<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3228
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3229<h4>
3230 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3231</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3232
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3233<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3234
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3235<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3236<pre>
3237 unwind
3238</pre>
3239
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3240<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3241<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3242 at the first callee in the dynamic call stack which used
3243 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3244 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3245
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3246<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3247<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3248 immediately halt. The dynamic call stack is then searched for the
3249 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3250 Once found, execution continues at the "exceptional" destination block
3251 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3252 instruction in the dynamic call chain, undefined behavior results.</p>
3253
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3254<p>Note that the code generator does not yet completely support unwind, and
3255that the invoke/unwind semantics are likely to change in future versions.</p>
3256
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3257</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3258
3259<!-- _______________________________________________________________________ -->
3260
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3261<h4>
3262 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3263</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3264
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3265<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3266
3267<h5>Syntax:</h5>
3268<pre>
3269 unreachable
3270</pre>
3271
3272<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3273<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3274 instruction is used to inform the optimizer that a particular portion of the
3275 code is not reachable. This can be used to indicate that the code after a
3276 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3277
3278<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3279<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3280
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3281</div>
3282
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3283</div>
3284
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3285<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3286<h3>
3287 <a name="binaryops">Binary Operations</a>
3288</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3289
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3290<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3291
3292<p>Binary operators are used to do most of the computation in a program. They
3293 require two operands of the same type, execute an operation on them, and
3294 produce a single value. The operands might represent multiple data, as is
3295 the case with the <a href="#t_vector">vector</a> data type. The result value
3296 has the same type as its operands.</p>
3297
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3298<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3299
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3300<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3301<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3302 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3303</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3304
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3305<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3306
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3307<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3308<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3309 &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]3310 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3311 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3312 &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]3313</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3314
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3315<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3316<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3317
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3318<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3319<p>The two arguments to the '<tt>add</tt>' instruction must
3320 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3321 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3322
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3323<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3324<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3325
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3326<p>If the sum has unsigned overflow, the result returned is the mathematical
3327 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]3328
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3329<p>Because LLVM integers use a two's complement representation, this instruction
3330 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3331
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3332<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3333 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3334 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3335 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3336 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3338<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3339<pre>
3340 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3341</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3342
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3343</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3344
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3345<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3346<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3347 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3348</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3349
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3350<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3351
3352<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3353<pre>
3354 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3355</pre>
3356
3357<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3358<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3359
3360<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3361<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3362 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3363 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3364
3365<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3366<p>The value produced is the floating point sum of the two operands.</p>
3367
3368<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3369<pre>
3370 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3371</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3372
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3373</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3374
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3375<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3376<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3377 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3378</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3379
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3380<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3381
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3382<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3383<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3384 &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]3385 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3386 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3387 &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]3388</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3389
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3390<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3391<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3392 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3393
3394<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3395 '<tt>neg</tt>' instruction present in most other intermediate
3396 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3397
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3398<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3399<p>The two arguments to the '<tt>sub</tt>' instruction must
3400 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3401 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3402
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3403<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3404<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3405
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3406<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3407 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3408 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3409
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3410<p>Because LLVM integers use a two's complement representation, this instruction
3411 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3412
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3413<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3414 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3415 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3416 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3417 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3418
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3419<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3420<pre>
3421 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3422 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3423</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3424
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3425</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3426
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3427<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3428<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3429 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3430</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3431
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3432<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3433
3434<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3435<pre>
3436 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3437</pre>
3438
3439<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3440<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3441 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3442
3443<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3444 '<tt>fneg</tt>' instruction present in most other intermediate
3445 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3446
3447<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3448<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3449 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3450 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3451
3452<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3453<p>The value produced is the floating point difference of the two operands.</p>
3454
3455<h5>Example:</h5>
3456<pre>
3457 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3458 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3459</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3460
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3461</div>
3462
3463<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3464<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3465 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3466</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3467
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3468<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3469
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3470<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3471<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3472 &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]3473 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3474 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3475 &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]3476</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3477
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3478<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3479<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3480
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3481<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3482<p>The two arguments to the '<tt>mul</tt>' instruction must
3483 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3484 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3485
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3486<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3487<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3488
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3489<p>If the result of the multiplication has unsigned overflow, the result
3490 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3491 width of the result.</p>
3492
3493<p>Because LLVM integers use a two's complement representation, and the result
3494 is the same width as the operands, this instruction returns the correct
3495 result for both signed and unsigned integers. If a full product
3496 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3497 be sign-extended or zero-extended as appropriate to the width of the full
3498 product.</p>
3499
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3500<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3501 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3502 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3503 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3504 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3505
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3506<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3507<pre>
3508 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3509</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3510
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3511</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3512
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3513<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3514<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3515 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3516</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3517
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3518<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3519
3520<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3521<pre>
3522 &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]3523</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3524
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3525<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3526<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3527
3528<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3529<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3530 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3531 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3532
3533<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3534<p>The value produced is the floating point product of the two operands.</p>
3535
3536<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3537<pre>
3538 &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]3539</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3540
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3541</div>
3542
3543<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3544<h4>
3545 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3546</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3547
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3548<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3549
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3550<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3551<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3552 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3553 &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]3554</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3555
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3556<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3557<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3558
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3559<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3560<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3561 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3562 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3563
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3564<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3565<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3566
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3567<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3568 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3569
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3570<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3571
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3572<p>If the <tt>exact</tt> keyword is present, the result value of the
3573 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3574 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3575
3576
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3577<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3578<pre>
3579 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3580</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3581
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3582</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3583
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3584<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3585<h4>
3586 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3587</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3588
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3589<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3590
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3591<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3592<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3593 &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]3594 &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]3595</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3596
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3597<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3598<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3599
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3600<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3601<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3602 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3603 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3604
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3605<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3606<p>The value produced is the signed integer quotient of the two operands rounded
3607 towards zero.</p>
3608
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3609<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3610 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3611
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3612<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3613 undefined behavior; this is a rare case, but can occur, for example, by doing
3614 a 32-bit division of -2147483648 by -1.</p>
3615
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3616<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3617 <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]3618 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3619
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3620<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3621<pre>
3622 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3623</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3624
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3625</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3626
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3627<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3628<h4>
3629 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3630</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3631
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3632<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3633
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3634<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3635<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3636 &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]3637</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3638
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3639<h5>Overview:</h5>
3640<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3641
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3642<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3643<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3644 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3645 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3646
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3647<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3648<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3649
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3650<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3651<pre>
3652 &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]3653</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3654
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3655</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3656
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3657<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3658<h4>
3659 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3660</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3661
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3662<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3663
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3664<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3665<pre>
3666 &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]3667</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3668
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3669<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3670<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3671 division of its two arguments.</p>
3672
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3673<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3674<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3675 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3676 values. Both arguments must have identical types.</p>
3677
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3678<h5>Semantics:</h5>
3679<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3680 This instruction always performs an unsigned division to get the
3681 remainder.</p>
3682
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3683<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3684 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3685
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3686<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3687
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3688<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3689<pre>
3690 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3691</pre>
3692
3693</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3694
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3695<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3696<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3697 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3698</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3699
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3700<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3701
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3702<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3703<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3704 &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]3705</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3706
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3707<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3708<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3709 division of its two operands. This instruction can also take
3710 <a href="#t_vector">vector</a> versions of the values in which case the
3711 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3712
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3713<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3714<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3715 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3716 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3717
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3718<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3719<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3720 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3721 <i>modulo</i> operator (where the result is either zero or has the same sign
3722 as the divisor, <tt>op2</tt>) of a value.
3723 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3724 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3725 Math Forum</a>. For a table of how this is implemented in various languages,
3726 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3727 Wikipedia: modulo operation</a>.</p>
3728
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3729<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3730 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3731
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3732<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3733 Overflow also leads to undefined behavior; this is a rare case, but can
3734 occur, for example, by taking the remainder of a 32-bit division of
3735 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3736 lets srem be implemented using instructions that return both the result of
3737 the division and the remainder.)</p>
3738
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3739<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3740<pre>
3741 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3742</pre>
3743
3744</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3745
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3746<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3747<h4>
3748 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3749</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3750
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3751<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3752
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3753<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3754<pre>
3755 &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]3756</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3757
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3758<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3759<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3760 its two operands.</p>
3761
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3762<h5>Arguments:</h5>
3763<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3764 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3765 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3766
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3767<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3768<p>This instruction returns the <i>remainder</i> of a division. The remainder
3769 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3770
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3771<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3772<pre>
3773 &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]3774</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3775
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3776</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3777
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3778</div>
3779
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3780<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3781<h3>
3782 <a name="bitwiseops">Bitwise Binary Operations</a>
3783</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3784
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3785<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3786
3787<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3788 program. They are generally very efficient instructions and can commonly be
3789 strength reduced from other instructions. They require two operands of the
3790 same type, execute an operation on them, and produce a single value. The
3791 resulting value is the same type as its operands.</p>
3792
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3793<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3794<h4>
3795 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3796</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3797
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3798<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3799
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3800<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3801<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3802 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3803 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3804 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3805 &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]3806</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3807
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3808<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3809<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3810 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3811
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3812<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3813<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3814 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3815 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3816
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3817<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3818<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3819 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3820 is (statically or dynamically) negative or equal to or larger than the number
3821 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3822 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3823 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3824
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3825<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3826 <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]3827 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3828 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3829 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3830 they would if the shift were expressed as a mul instruction with the same
3831 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3832
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3833<h5>Example:</h5>
3834<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3835 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3836 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3837 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3838 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3839 &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]3840</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3841
Reid Spencer04e259b2007-01-31 21:39:12 +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<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3845<h4>
3846 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3847</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3848
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3849<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3850
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3851<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3852<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3853 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3854 &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]3855</pre>
3856
3857<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3858<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3859 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3860
3861<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3862<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3863 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3864 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3865
3866<h5>Semantics:</h5>
3867<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3868 significant bits of the result will be filled with zero bits after the shift.
3869 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3870 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3871 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3872 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3873
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3874<p>If the <tt>exact</tt> keyword is present, the result value of the
3875 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3876 shifted out are non-zero.</p>
3877
3878
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3879<h5>Example:</h5>
3880<pre>
3881 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3882 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3883 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3884 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3885 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3886 &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]3887</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3888
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3889</div>
3890
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3891<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3892<h4>
3893 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3894</h4>
3895
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3896<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3897
3898<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3899<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3900 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3901 &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]3902</pre>
3903
3904<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3905<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3906 operand shifted to the right a specified number of bits with sign
3907 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3908
3909<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3910<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3911 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3912 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3913
3914<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3915<p>This instruction always performs an arithmetic shift right operation, The
3916 most significant bits of the result will be filled with the sign bit
3917 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3918 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3919 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3920 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3921
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3922<p>If the <tt>exact</tt> keyword is present, the result value of the
3923 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3924 shifted out are non-zero.</p>
3925
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3926<h5>Example:</h5>
3927<pre>
3928 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3929 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3930 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3931 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3932 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3933 &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]3934</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3935
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3936</div>
3937
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3938<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3939<h4>
3940 <a name="i_and">'<tt>and</tt>' Instruction</a>
3941</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3942
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3943<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3944
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3945<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3946<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3947 &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]3948</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3949
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3950<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3951<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3952 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3953
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3954<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3955<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3956 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3957 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3958
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3959<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3960<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3961
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3962<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3963 <tbody>
3964 <tr>
3965 <td>In0</td>
3966 <td>In1</td>
3967 <td>Out</td>
3968 </tr>
3969 <tr>
3970 <td>0</td>
3971 <td>0</td>
3972 <td>0</td>
3973 </tr>
3974 <tr>
3975 <td>0</td>
3976 <td>1</td>
3977 <td>0</td>
3978 </tr>
3979 <tr>
3980 <td>1</td>
3981 <td>0</td>
3982 <td>0</td>
3983 </tr>
3984 <tr>
3985 <td>1</td>
3986 <td>1</td>
3987 <td>1</td>
3988 </tr>
3989 </tbody>
3990</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3991
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3992<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3993<pre>
3994 &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]3995 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3996 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3997</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3998</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3999<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4000<h4>
4001 <a name="i_or">'<tt>or</tt>' Instruction</a>
4002</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4003
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4004<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4005
4006<h5>Syntax:</h5>
4007<pre>
4008 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4009</pre>
4010
4011<h5>Overview:</h5>
4012<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4013 two operands.</p>
4014
4015<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4016<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4017 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4018 values. Both arguments must have identical types.</p>
4019
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4020<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4021<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4022
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4023<table border="1" cellspacing="0" cellpadding="4">
4024 <tbody>
4025 <tr>
4026 <td>In0</td>
4027 <td>In1</td>
4028 <td>Out</td>
4029 </tr>
4030 <tr>
4031 <td>0</td>
4032 <td>0</td>
4033 <td>0</td>
4034 </tr>
4035 <tr>
4036 <td>0</td>
4037 <td>1</td>
4038 <td>1</td>
4039 </tr>
4040 <tr>
4041 <td>1</td>
4042 <td>0</td>
4043 <td>1</td>
4044 </tr>
4045 <tr>
4046 <td>1</td>
4047 <td>1</td>
4048 <td>1</td>
4049 </tr>
4050 </tbody>
4051</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4052
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4053<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4054<pre>
4055 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4056 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4057 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4058</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4059
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4060</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4061
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4062<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4063<h4>
4064 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4065</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4066
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4067<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4068
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4069<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4070<pre>
4071 &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]4072</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4073
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4074<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4075<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4076 its two operands. The <tt>xor</tt> is used to implement the "one's
4077 complement" operation, which is the "~" operator in C.</p>
4078
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4079<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4080<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4081 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4082 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4083
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4084<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4085<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4086
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4087<table border="1" cellspacing="0" cellpadding="4">
4088 <tbody>
4089 <tr>
4090 <td>In0</td>
4091 <td>In1</td>
4092 <td>Out</td>
4093 </tr>
4094 <tr>
4095 <td>0</td>
4096 <td>0</td>
4097 <td>0</td>
4098 </tr>
4099 <tr>
4100 <td>0</td>
4101 <td>1</td>
4102 <td>1</td>
4103 </tr>
4104 <tr>
4105 <td>1</td>
4106 <td>0</td>
4107 <td>1</td>
4108 </tr>
4109 <tr>
4110 <td>1</td>
4111 <td>1</td>
4112 <td>0</td>
4113 </tr>
4114 </tbody>
4115</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4116
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4117<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4118<pre>
4119 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4120 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4121 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4122 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4123</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4124
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4125</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4126
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4127</div>
4128
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4129<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4130<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4131 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4132</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4133
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4134<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4135
4136<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4137 target-independent manner. These instructions cover the element-access and
4138 vector-specific operations needed to process vectors effectively. While LLVM
4139 does directly support these vector operations, many sophisticated algorithms
4140 will want to use target-specific intrinsics to take full advantage of a
4141 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4142
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4143<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4144<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4145 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4146</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4147
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4148<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4149
4150<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4151<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4152 &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]4153</pre>
4154
4155<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4156<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4157 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4158
4159
4160<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4161<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4162 of <a href="#t_vector">vector</a> type. The second operand is an index
4163 indicating the position from which to extract the element. The index may be
4164 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4165
4166<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4167<p>The result is a scalar of the same type as the element type of
4168 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4169 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4170 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4171
4172<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4173<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4174 &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]4175</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4176
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4177</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4178
4179<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4180<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4181 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4182</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4183
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4184<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4185
4186<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4187<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4188 &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]4189</pre>
4190
4191<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4192<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4193 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4194
4195<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4196<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4197 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4198 whose type must equal the element type of the first operand. The third
4199 operand is an index indicating the position at which to insert the value.
4200 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4201
4202<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4203<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4204 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4205 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4206 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4207
4208<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4209<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4210 &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]4211</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4212
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4213</div>
4214
4215<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4216<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4217 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4218</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4219
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4220<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4221
4222<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4223<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4224 &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]4225</pre>
4226
4227<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4228<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4229 from two input vectors, returning a vector with the same element type as the
4230 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4231
4232<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4233<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4234 with types that match each other. The third argument is a shuffle mask whose
4235 element type is always 'i32'. The result of the instruction is a vector
4236 whose length is the same as the shuffle mask and whose element type is the
4237 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4238
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4239<p>The shuffle mask operand is required to be a constant vector with either
4240 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4241
4242<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4243<p>The elements of the two input vectors are numbered from left to right across
4244 both of the vectors. The shuffle mask operand specifies, for each element of
4245 the result vector, which element of the two input vectors the result element
4246 gets. The element selector may be undef (meaning "don't care") and the
4247 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4248
4249<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4250<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4251 &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]4252 &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]4253 &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]4254 &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]4255 &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]4256 &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]4257 &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]4258 &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]4259</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4260
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4261</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4262
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4263</div>
4264
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4265<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4266<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4267 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4268</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4269
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4270<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4271
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4272<p>LLVM supports several instructions for working with
4273 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4274
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4275<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4276<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4277 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4278</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4279
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4280<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4281
4282<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4283<pre>
4284 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4285</pre>
4286
4287<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4288<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4289 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4290
4291<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4292<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4293 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4294 <a href="#t_array">array</a> type. The operands are constant indices to
4295 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4296 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4297 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4298 <ul>
4299 <li>Since the value being indexed is not a pointer, the first index is
4300 omitted and assumed to be zero.</li>
4301 <li>At least one index must be specified.</li>
4302 <li>Not only struct indices but also array indices must be in
4303 bounds.</li>
4304 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4305
4306<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4307<p>The result is the value at the position in the aggregate specified by the
4308 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4309
4310<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4311<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4312 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4313</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4314
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4315</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4316
4317<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4318<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4319 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4320</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4321
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4322<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4323
4324<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4325<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4326 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4327</pre>
4328
4329<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4330<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4331 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4332
4333<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4334<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4335 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4336 <a href="#t_array">array</a> type. The second operand is a first-class
4337 value to insert. The following operands are constant indices indicating
4338 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]4339 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4340 value to insert must have the same type as the value identified by the
4341 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4342
4343<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4344<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4345 that of <tt>val</tt> except that the value at the position specified by the
4346 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4347
4348<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4349<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4350 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4351 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4352 %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]4353</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4354
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4355</div>
4356
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4357</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4358
4359<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4360<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4361 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4362</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4363
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4364<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4365
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4366<p>A key design point of an SSA-based representation is how it represents
4367 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4368 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4369 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4370
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4371<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4372<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4373 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4374</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4375
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4376<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4377
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4378<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4379<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4380 &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]4381</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4382
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4383<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4384<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4385 currently executing function, to be automatically released when this function
4386 returns to its caller. The object is always allocated in the generic address
4387 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4388
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4389<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4390<p>The '<tt>alloca</tt>' instruction
4391 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4392 runtime stack, returning a pointer of the appropriate type to the program.
4393 If "NumElements" is specified, it is the number of elements allocated,
4394 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4395 specified, the value result of the allocation is guaranteed to be aligned to
4396 at least that boundary. If not specified, or if zero, the target can choose
4397 to align the allocation on any convenient boundary compatible with the
4398 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4399
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4400<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4401
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4402<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4403<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4404 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4405 memory is automatically released when the function returns. The
4406 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4407 variables that must have an address available. When the function returns
4408 (either with the <tt><a href="#i_ret">ret</a></tt>
4409 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4410 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4411
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4412<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4413<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4414 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4415 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4416 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4417 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4418</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4419
Misha Brukman76307852003-11-08 01:05:38 +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<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4423<h4>
4424 <a name="i_load">'<tt>load</tt>' Instruction</a>
4425</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4426
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4427<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4428
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4429<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4430<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4431 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4432 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4433 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4434</pre>
4435
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4436<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4437<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4438
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4439<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4440<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4441 from which to load. The pointer must point to
4442 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4443 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4444 number or order of execution of this <tt>load</tt> with other <a
4445 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4446
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4447<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4448 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]4449 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4450 alignment for the target. It is the responsibility of the code emitter to
4451 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4452 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4453 produce less efficient code. An alignment of 1 is always safe.</p>
4454
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4455<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4456 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4457 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4458 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4459 and code generator that this load is not expected to be reused in the cache.
4460 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4461 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4462
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4463<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4464<p>The location of memory pointed to is loaded. If the value being loaded is of
4465 scalar type then the number of bytes read does not exceed the minimum number
4466 of bytes needed to hold all bits of the type. For example, loading an
4467 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4468 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4469 is undefined if the value was not originally written using a store of the
4470 same type.</p>
4471
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4472<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4473<pre>
4474 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4475 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4476 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4477</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4478
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4479</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4480
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4481<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4482<h4>
4483 <a name="i_store">'<tt>store</tt>' Instruction</a>
4484</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4485
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4486<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4487
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4488<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4489<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4490 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>
4491 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]4492</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4493
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4494<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4495<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4496
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4497<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4498<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4499 and an address at which to store it. The type of the
4500 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4501 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4502 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4503 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4504 order of execution of this <tt>store</tt> with other <a
4505 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4506
4507<p>The optional constant "align" argument specifies the alignment of the
4508 operation (that is, the alignment of the memory address). A value of 0 or an
4509 omitted "align" argument means that the operation has the preferential
4510 alignment for the target. It is the responsibility of the code emitter to
4511 ensure that the alignment information is correct. Overestimating the
4512 alignment results in an undefined behavior. Underestimating the alignment may
4513 produce less efficient code. An alignment of 1 is always safe.</p>
4514
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4515<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4516 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4517 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4518 instruction tells the optimizer and code generator that this load is
4519 not expected to be reused in the cache. The code generator may
4520 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4521 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4522
4523
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4524<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4525<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4526 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4527 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4528 does not exceed the minimum number of bytes needed to hold all bits of the
4529 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4530 writing a value of a type like <tt>i20</tt> with a size that is not an
4531 integral number of bytes, it is unspecified what happens to the extra bits
4532 that do not belong to the type, but they will typically be overwritten.</p>
4533
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4534<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4535<pre>
4536 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4537 store i32 3, i32* %ptr <i>; yields {void}</i>
4538 %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]4539</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4540
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4541</div>
4542
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4543<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4544<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4545 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4546</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4547
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4548<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4549
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4550<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4551<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4552 &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]4553 &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]4554</pre>
4555
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4556<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4557<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4558 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4559 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4560
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4561<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4562<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4563 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4564 elements of the aggregate object are indexed. The interpretation of each
4565 index is dependent on the type being indexed into. The first index always
4566 indexes the pointer value given as the first argument, the second index
4567 indexes a value of the type pointed to (not necessarily the value directly
4568 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4569 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4570 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4571 can never be pointers, since that would require loading the pointer before
4572 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4573
4574<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]4575 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4576 integer <b>constants</b> are allowed. When indexing into an array, pointer
4577 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]4578 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4579
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4580<p>For example, let's consider a C code fragment and how it gets compiled to
4581 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4582
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4583<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4584struct RT {
4585 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4586 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4587 char C;
4588};
4589struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4590 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4591 double Y;
4592 struct RT Z;
4593};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4594
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4595int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4596 return &amp;s[1].Z.B[5][13];
4597}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4598</pre>
4599
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4600<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4601
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4602<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4603%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4604%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4605
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4606define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4607entry:
4608 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4609 ret i32* %reg
4610}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4611</pre>
4612
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4613<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4614<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]4615 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4616 }</tt>' type, a structure. The second index indexes into the third element
4617 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4618 i8 }</tt>' type, another structure. The third index indexes into the second
4619 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4620 array. The two dimensions of the array are subscripted into, yielding an
4621 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4622 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4623
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4624<p>Note that it is perfectly legal to index partially through a structure,
4625 returning a pointer to an inner element. Because of this, the LLVM code for
4626 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4627
4628<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4629 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4630 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4631 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4632 %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]4633 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4634 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4635 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4636 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4637</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4638
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4639<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4640 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4641 base pointer is not an <i>in bounds</i> address of an allocated object,
4642 or if any of the addresses that would be formed by successive addition of
4643 the offsets implied by the indices to the base address with infinitely
4644 precise arithmetic are not an <i>in bounds</i> address of that allocated
4645 object. The <i>in bounds</i> addresses for an allocated object are all
4646 the addresses that point into the object, plus the address one byte past
4647 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4648
4649<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4650 the base address with silently-wrapping two's complement arithmetic, and
4651 the result value of the <tt>getelementptr</tt> may be outside the object
4652 pointed to by the base pointer. The result value may not necessarily be
4653 used to access memory though, even if it happens to point into allocated
4654 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4655 section for more information.</p>
4656
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4657<p>The getelementptr instruction is often confusing. For some more insight into
4658 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4659
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4660<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4661<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4662 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4663 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4664 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4665 %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]4666 <i>; yields i8*:eptr</i>
4667 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4668 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4669 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4670</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4671
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4672</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4673
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4674</div>
4675
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4676<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4677<h3>
4678 <a name="convertops">Conversion Operations</a>
4679</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4680
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4681<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4682
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4683<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4684 which all take a single operand and a type. They perform various bit
4685 conversions on the operand.</p>
4686
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4687<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4688<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4689 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4690</h4>
4691
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4692<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4693
4694<h5>Syntax:</h5>
4695<pre>
4696 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4697</pre>
4698
4699<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4700<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4701 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4702
4703<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4704<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4705 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4706 of the same number of integers.
4707 The bit size of the <tt>value</tt> must be larger than
4708 the bit size of the destination type, <tt>ty2</tt>.
4709 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4710
4711<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4712<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4713 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4714 source size must be larger than the destination size, <tt>trunc</tt> cannot
4715 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4716
4717<h5>Example:</h5>
4718<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4719 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4720 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4721 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4722 %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]4723</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4724
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4725</div>
4726
4727<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4728<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4729 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4730</h4>
4731
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4732<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4733
4734<h5>Syntax:</h5>
4735<pre>
4736 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4737</pre>
4738
4739<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4740<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4741 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4742
4743
4744<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4745<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4746 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4747 of the same number of integers.
4748 The bit size of the <tt>value</tt> must be smaller than
4749 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4750 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4751
4752<h5>Semantics:</h5>
4753<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]4754 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4755
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4756<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]4757
4758<h5>Example:</h5>
4759<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4760 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4761 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4762 %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]4763</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4764
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4765</div>
4766
4767<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4768<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4769 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4770</h4>
4771
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4772<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4773
4774<h5>Syntax:</h5>
4775<pre>
4776 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4777</pre>
4778
4779<h5>Overview:</h5>
4780<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4781
4782<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4783<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4784 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4785 of the same number of integers.
4786 The bit size of the <tt>value</tt> must be smaller than
4787 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4788 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4789
4790<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4791<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4792 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4793 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4794
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4795<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]4796
4797<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4798<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4799 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4800 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4801 %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]4802</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4803
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4804</div>
4805
4806<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4807<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4808 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4809</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4810
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4811<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4812
4813<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4814<pre>
4815 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4816</pre>
4817
4818<h5>Overview:</h5>
4819<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4820 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4821
4822<h5>Arguments:</h5>
4823<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4824 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4825 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]4826 <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]4827 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4828
4829<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4830<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4831 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4832 <a href="#t_floating">floating point</a> type. If the value cannot fit
4833 within the destination type, <tt>ty2</tt>, then the results are
4834 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4835
4836<h5>Example:</h5>
4837<pre>
4838 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4839 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4840</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4841
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4842</div>
4843
4844<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4845<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4846 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4847</h4>
4848
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4849<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4850
4851<h5>Syntax:</h5>
4852<pre>
4853 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4854</pre>
4855
4856<h5>Overview:</h5>
4857<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]4858 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4859
4860<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4861<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4862 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4863 a <a href="#t_floating">floating point</a> type to cast it to. The source
4864 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4865
4866<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4867<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4868 <a href="#t_floating">floating point</a> type to a larger
4869 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4870 used to make a <i>no-op cast</i> because it always changes bits. Use
4871 <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]4872
4873<h5>Example:</h5>
4874<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]4875 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4876 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4877</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4878
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4879</div>
4880
4881<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4882<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4883 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4884</h4>
4885
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4886<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4887
4888<h5>Syntax:</h5>
4889<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4890 &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]4891</pre>
4892
4893<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4894<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4895 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4896
4897<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4898<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4899 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4900 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4901 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4902 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4903
4904<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4905<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4906 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4907 towards zero) unsigned integer value. If the value cannot fit
4908 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4909
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4910<h5>Example:</h5>
4911<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4912 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4913 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4914 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4915</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4916
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4917</div>
4918
4919<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4920<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4921 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4922</h4>
4923
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4924<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4925
4926<h5>Syntax:</h5>
4927<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4928 &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]4929</pre>
4930
4931<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4932<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4933 <a href="#t_floating">floating point</a> <tt>value</tt> to
4934 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4935
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4936<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4937<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4938 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4939 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4940 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4941 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4942
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4943<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4944<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4945 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4946 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4947 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4948
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4949<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4950<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4951 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4952 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4953 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4954</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4955
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4956</div>
4957
4958<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4959<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4960 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4961</h4>
4962
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4963<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4964
4965<h5>Syntax:</h5>
4966<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4967 &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]4968</pre>
4969
4970<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4971<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4972 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4973
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4974<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4975<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]4976 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4977 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4978 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4979 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4980
4981<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4982<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4983 integer quantity and converts it to the corresponding floating point
4984 value. If the value cannot fit in the floating point value, the results are
4985 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4986
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4987<h5>Example:</h5>
4988<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4989 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4990 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4991</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4992
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4993</div>
4994
4995<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4996<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4997 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4998</h4>
4999
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5000<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5001
5002<h5>Syntax:</h5>
5003<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5004 &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]5005</pre>
5006
5007<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5008<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5009 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5010
5011<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5012<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]5013 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5014 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5015 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5016 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5017
5018<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5019<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5020 quantity and converts it to the corresponding floating point value. If the
5021 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5022
5023<h5>Example:</h5>
5024<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5025 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5026 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5027</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5028
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5029</div>
5030
5031<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5032<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5033 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5034</h4>
5035
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5036<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5037
5038<h5>Syntax:</h5>
5039<pre>
5040 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5041</pre>
5042
5043<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5044<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5045 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5046
5047<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5048<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5049 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5050 <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]5051
5052<h5>Semantics:</h5>
5053<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5054 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5055 truncating or zero extending that value to the size of the integer type. If
5056 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5057 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5058 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5059 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5060
5061<h5>Example:</h5>
5062<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5063 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5064 %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]5065</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5066
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5067</div>
5068
5069<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5070<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5071 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5072</h4>
5073
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5074<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5075
5076<h5>Syntax:</h5>
5077<pre>
5078 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5079</pre>
5080
5081<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5082<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5083 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5084
5085<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5086<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5087 value to cast, and a type to cast it to, which must be a
5088 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5089
5090<h5>Semantics:</h5>
5091<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5092 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5093 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5094 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5095 than the size of a pointer then a zero extension is done. If they are the
5096 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5097
5098<h5>Example:</h5>
5099<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5100 %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]5101 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5102 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5103</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5104
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5105</div>
5106
5107<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5108<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5109 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5110</h4>
5111
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5112<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5113
5114<h5>Syntax:</h5>
5115<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5116 &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]5117</pre>
5118
5119<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5120<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5121 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5122
5123<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5124<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5125 non-aggregate first class value, and a type to cast it to, which must also be
5126 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5127 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5128 identical. If the source type is a pointer, the destination type must also be
5129 a pointer. This instruction supports bitwise conversion of vectors to
5130 integers and to vectors of other types (as long as they have the same
5131 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5132
5133<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5134<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5135 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5136 this conversion. The conversion is done as if the <tt>value</tt> had been
5137 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5138 be converted to other pointer types with this instruction. To convert
5139 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5140 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5141
5142<h5>Example:</h5>
5143<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5144 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5145 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5146 %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]5147</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5148
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5149</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5150
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5151</div>
5152
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5153<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5154<h3>
5155 <a name="otherops">Other Operations</a>
5156</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5157
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5158<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5159
5160<p>The instructions in this category are the "miscellaneous" instructions, which
5161 defy better classification.</p>
5162
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5163<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5164<h4>
5165 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5166</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5167
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5168<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5169
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5170<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5171<pre>
5172 &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]5173</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5174
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5175<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5176<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5177 boolean values based on comparison of its two integer, integer vector, or
5178 pointer operands.</p>
5179
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5180<h5>Arguments:</h5>
5181<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5182 the condition code indicating the kind of comparison to perform. It is not a
5183 value, just a keyword. The possible condition code are:</p>
5184
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5185<ol>
5186 <li><tt>eq</tt>: equal</li>
5187 <li><tt>ne</tt>: not equal </li>
5188 <li><tt>ugt</tt>: unsigned greater than</li>
5189 <li><tt>uge</tt>: unsigned greater or equal</li>
5190 <li><tt>ult</tt>: unsigned less than</li>
5191 <li><tt>ule</tt>: unsigned less or equal</li>
5192 <li><tt>sgt</tt>: signed greater than</li>
5193 <li><tt>sge</tt>: signed greater or equal</li>
5194 <li><tt>slt</tt>: signed less than</li>
5195 <li><tt>sle</tt>: signed less or equal</li>
5196</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5197
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5198<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5199 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5200 typed. They must also be identical types.</p>
5201
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5202<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5203<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5204 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5205 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]5206 result, as follows:</p>
5207
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5208<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5209 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5210 <tt>false</tt> otherwise. No sign interpretation is necessary or
5211 performed.</li>
5212
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5213 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5214 <tt>false</tt> otherwise. No sign interpretation is necessary or
5215 performed.</li>
5216
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5217 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5218 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5219
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5220 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5221 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5222 to <tt>op2</tt>.</li>
5223
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5224 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5225 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5226
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5227 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5228 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5229
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5230 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5231 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5232
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5233 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5234 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5235 to <tt>op2</tt>.</li>
5236
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5237 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5238 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5239
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5240 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5241 <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]5242</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5243
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5244<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5245 values are compared as if they were integers.</p>
5246
5247<p>If the operands are integer vectors, then they are compared element by
5248 element. The result is an <tt>i1</tt> vector with the same number of elements
5249 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5250
5251<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5252<pre>
5253 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5254 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5255 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5256 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5257 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5258 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5259</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5260
5261<p>Note that the code generator does not yet support vector types with
5262 the <tt>icmp</tt> instruction.</p>
5263
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5264</div>
5265
5266<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5267<h4>
5268 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5269</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5271<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5272
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5273<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5274<pre>
5275 &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]5276</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5277
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5278<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5279<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5280 values based on comparison of its operands.</p>
5281
5282<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]5283(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5284
5285<p>If the operands are floating point vectors, then the result type is a vector
5286 of boolean with the same number of elements as the operands being
5287 compared.</p>
5288
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5289<h5>Arguments:</h5>
5290<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5291 the condition code indicating the kind of comparison to perform. It is not a
5292 value, just a keyword. The possible condition code are:</p>
5293
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5294<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5295 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5296 <li><tt>oeq</tt>: ordered and equal</li>
5297 <li><tt>ogt</tt>: ordered and greater than </li>
5298 <li><tt>oge</tt>: ordered and greater than or equal</li>
5299 <li><tt>olt</tt>: ordered and less than </li>
5300 <li><tt>ole</tt>: ordered and less than or equal</li>
5301 <li><tt>one</tt>: ordered and not equal</li>
5302 <li><tt>ord</tt>: ordered (no nans)</li>
5303 <li><tt>ueq</tt>: unordered or equal</li>
5304 <li><tt>ugt</tt>: unordered or greater than </li>
5305 <li><tt>uge</tt>: unordered or greater than or equal</li>
5306 <li><tt>ult</tt>: unordered or less than </li>
5307 <li><tt>ule</tt>: unordered or less than or equal</li>
5308 <li><tt>une</tt>: unordered or not equal</li>
5309 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5310 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5311</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5312
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5313<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5314 <i>unordered</i> means that either operand may be a QNAN.</p>
5315
5316<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5317 a <a href="#t_floating">floating point</a> type or
5318 a <a href="#t_vector">vector</a> of floating point type. They must have
5319 identical types.</p>
5320
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5321<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5322<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5323 according to the condition code given as <tt>cond</tt>. If the operands are
5324 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5325 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5326 follows:</p>
5327
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5328<ol>
5329 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5330
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5331 <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]5332 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5333
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5334 <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]5335 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5336
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5337 <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]5338 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5339
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5340 <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]5341 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5342
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5343 <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]5344 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5345
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5346 <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]5347 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5348
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5349 <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]5350
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5351 <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]5352 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5353
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5354 <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]5355 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5356
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5357 <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]5358 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5359
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5360 <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]5361 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5362
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5363 <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]5364 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5365
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5366 <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]5367 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5368
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5369 <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]5370
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5371 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5372</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5373
5374<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5375<pre>
5376 &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]5377 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5378 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5379 &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]5380</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5381
5382<p>Note that the code generator does not yet support vector types with
5383 the <tt>fcmp</tt> instruction.</p>
5384
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5385</div>
5386
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5387<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5388<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5389 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5390</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5391
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5392<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5393
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5394<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5395<pre>
5396 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5397</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5398
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5399<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5400<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5401 SSA graph representing the function.</p>
5402
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5403<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5404<p>The type of the incoming values is specified with the first type field. After
5405 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5406 one pair for each predecessor basic block of the current block. Only values
5407 of <a href="#t_firstclass">first class</a> type may be used as the value
5408 arguments to the PHI node. Only labels may be used as the label
5409 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5410
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5411<p>There must be no non-phi instructions between the start of a basic block and
5412 the PHI instructions: i.e. PHI instructions must be first in a basic
5413 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5414
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5415<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5416 occur on the edge from the corresponding predecessor block to the current
5417 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5418 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5419
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5420<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5421<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5422 specified by the pair corresponding to the predecessor basic block that
5423 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5424
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5425<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5426<pre>
5427Loop: ; Infinite loop that counts from 0 on up...
5428 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5429 %nextindvar = add i32 %indvar, 1
5430 br label %Loop
5431</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5432
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5433</div>
5434
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5435<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5436<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5437 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5438</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5439
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5440<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5441
5442<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5443<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5444 &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>
5445
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5446 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5447</pre>
5448
5449<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5450<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5451 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5452
5453
5454<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5455<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5456 values indicating the condition, and two values of the
5457 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5458 vectors and the condition is a scalar, then entire vectors are selected, not
5459 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5460
5461<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5462<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5463 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5464
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5465<p>If the condition is a vector of i1, then the value arguments must be vectors
5466 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5467
5468<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5469<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5470 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5471</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5472
5473<p>Note that the code generator does not yet support conditions
5474 with vector type.</p>
5475
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5476</div>
5477
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5478<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5479<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5480 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5481</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5482
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5483<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5484
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5485<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5486<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5487 &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]5488</pre>
5489
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5490<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5491<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5492
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5493<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5494<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5495
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5496<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5497 <li>The optional "tail" marker indicates that the callee function does not
5498 access any allocas or varargs in the caller. Note that calls may be
5499 marked "tail" even if they do not occur before
5500 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5501 present, the function call is eligible for tail call optimization,
5502 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5503 optimized into a jump</a>. The code generator may optimize calls marked
5504 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5505 sibling call optimization</a> when the caller and callee have
5506 matching signatures, or 2) forced tail call optimization when the
5507 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5508 <ul>
5509 <li>Caller and callee both have the calling
5510 convention <tt>fastcc</tt>.</li>
5511 <li>The call is in tail position (ret immediately follows call and ret
5512 uses value of call or is void).</li>
5513 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5514 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5515 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5516 constraints are met.</a></li>
5517 </ul>
5518 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5519
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5520 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5521 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5522 defaults to using C calling conventions. The calling convention of the
5523 call must match the calling convention of the target function, or else the
5524 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5525
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5526 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5527 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5528 '<tt>inreg</tt>' attributes are valid here.</li>
5529
5530 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5531 type of the return value. Functions that return no value are marked
5532 <tt><a href="#t_void">void</a></tt>.</li>
5533
5534 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5535 being invoked. The argument types must match the types implied by this
5536 signature. This type can be omitted if the function is not varargs and if
5537 the function type does not return a pointer to a function.</li>
5538
5539 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5540 be invoked. In most cases, this is a direct function invocation, but
5541 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5542 to function value.</li>
5543
5544 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5545 signature argument types and parameter attributes. All arguments must be
5546 of <a href="#t_firstclass">first class</a> type. If the function
5547 signature indicates the function accepts a variable number of arguments,
5548 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5549
5550 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5551 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5552 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5553</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5554
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5555<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5556<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5557 a specified function, with its incoming arguments bound to the specified
5558 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5559 function, control flow continues with the instruction after the function
5560 call, and the return value of the function is bound to the result
5561 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5562
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5563<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5564<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5565 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5566 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5567 %X = tail call i32 @foo() <i>; yields i32</i>
5568 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5569 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5570
5571 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5572 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5573 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5574 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5575 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5576 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5577</pre>
5578
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5579<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5580standard C99 library as being the C99 library functions, and may perform
5581optimizations or generate code for them under that assumption. This is
5582something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5583freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5584
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5585</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5586
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5587<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5588<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5589 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5590</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5591
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5592<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5593
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5594<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5595<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5596 &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]5597</pre>
5598
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5599<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5600<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5601 the "variable argument" area of a function call. It is used to implement the
5602 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5603
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5604<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5605<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5606 argument. It returns a value of the specified argument type and increments
5607 the <tt>va_list</tt> to point to the next argument. The actual type
5608 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5609
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5610<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5611<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5612 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5613 to the next argument. For more information, see the variable argument
5614 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5615
5616<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]5617 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5618 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5619
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5620<p><tt>va_arg</tt> is an LLVM instruction instead of
5621 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5622 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5623
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5624<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5625<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5626
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5627<p>Note that the code generator does not yet fully support va_arg on many
5628 targets. Also, it does not currently support va_arg with aggregate types on
5629 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5630
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5631</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5632
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5633</div>
5634
5635</div>
5636
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5637<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5638<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5639<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5640
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5641<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5642
5643<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5644 well known names and semantics and are required to follow certain
5645 restrictions. Overall, these intrinsics represent an extension mechanism for
5646 the LLVM language that does not require changing all of the transformations
5647 in LLVM when adding to the language (or the bitcode reader/writer, the
5648 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5649
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5650<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5651 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5652 begin with this prefix. Intrinsic functions must always be external
5653 functions: you cannot define the body of intrinsic functions. Intrinsic
5654 functions may only be used in call or invoke instructions: it is illegal to
5655 take the address of an intrinsic function. Additionally, because intrinsic
5656 functions are part of the LLVM language, it is required if any are added that
5657 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5658
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5659<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5660 family of functions that perform the same operation but on different data
5661 types. Because LLVM can represent over 8 million different integer types,
5662 overloading is used commonly to allow an intrinsic function to operate on any
5663 integer type. One or more of the argument types or the result type can be
5664 overloaded to accept any integer type. Argument types may also be defined as
5665 exactly matching a previous argument's type or the result type. This allows
5666 an intrinsic function which accepts multiple arguments, but needs all of them
5667 to be of the same type, to only be overloaded with respect to a single
5668 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5669
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5670<p>Overloaded intrinsics will have the names of its overloaded argument types
5671 encoded into its function name, each preceded by a period. Only those types
5672 which are overloaded result in a name suffix. Arguments whose type is matched
5673 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5674 can take an integer of any width and returns an integer of exactly the same
5675 integer width. This leads to a family of functions such as
5676 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5677 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5678 suffix is required. Because the argument's type is matched against the return
5679 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5680
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5681<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5682 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5683
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5684<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5685<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5686 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5687</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5688
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5689<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5690
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5691<p>Variable argument support is defined in LLVM with
5692 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5693 intrinsic functions. These functions are related to the similarly named
5694 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5695
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5696<p>All of these functions operate on arguments that use a target-specific value
5697 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5698 not define what this type is, so all transformations should be prepared to
5699 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5700
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5701<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]5702 instruction and the variable argument handling intrinsic functions are
5703 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5704
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5705<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5706define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5707 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5708 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5709 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5710 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5711
5712 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5713 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5714
5715 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5716 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5717 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5718 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5719 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5720
5721 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5722 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5723 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5724}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5725
5726declare void @llvm.va_start(i8*)
5727declare void @llvm.va_copy(i8*, i8*)
5728declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5729</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5730
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5731<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5732<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5733 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5734</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5735
5736
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5737<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5738
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5739<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5740<pre>
5741 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5742</pre>
5743
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5744<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5745<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5746 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]5747
5748<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5749<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]5750
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5751<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5752<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]5753 macro available in C. In a target-dependent way, it initializes
5754 the <tt>va_list</tt> element to which the argument points, so that the next
5755 call to <tt>va_arg</tt> will produce the first variable argument passed to
5756 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5757 need to know the last argument of the function as the compiler can figure
5758 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5759
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5760</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5761
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5762<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5763<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5764 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5765</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5766
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5767<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5768
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5769<h5>Syntax:</h5>
5770<pre>
5771 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5772</pre>
5773
5774<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5775<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5776 which has been initialized previously
5777 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5778 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5779
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5780<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5781<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]5782
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5783<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5784<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]5785 macro available in C. In a target-dependent way, it destroys
5786 the <tt>va_list</tt> element to which the argument points. Calls
5787 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5788 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5789 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5790
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5791</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5792
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5793<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5794<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5795 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5796</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5797
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5798<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5799
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5800<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5801<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5802 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5803</pre>
5804
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5805<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5806<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5807 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5808
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5809<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5810<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]5811 The second argument is a pointer to a <tt>va_list</tt> element to copy
5812 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5813
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5814<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5815<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]5816 macro available in C. In a target-dependent way, it copies the
5817 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5818 element. This intrinsic is necessary because
5819 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5820 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5821
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5822</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5823
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5824</div>
5825
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5826<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5827<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5828 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5829</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5830
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5831<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5832
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5833<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5834Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5835intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5836roots on the stack</a>, as well as garbage collector implementations that
5837require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5838barriers. Front-ends for type-safe garbage collected languages should generate
5839these intrinsics to make use of the LLVM garbage collectors. For more details,
5840see <a href="GarbageCollection.html">Accurate Garbage Collection with
5841LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5842
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5843<p>The garbage collection intrinsics only operate on objects in the generic
5844 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5845
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5846<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5847<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5848 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5849</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5850
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5851<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5852
5853<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5854<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5855 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5856</pre>
5857
5858<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5859<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]5860 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5861
5862<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5863<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5864 root pointer. The second pointer (which must be either a constant or a
5865 global value address) contains the meta-data to be associated with the
5866 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5867
5868<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5869<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]5870 location. At compile-time, the code generator generates information to allow
5871 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5872 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5873 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5874
5875</div>
5876
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5877<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5878<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5879 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5880</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5881
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5882<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5883
5884<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5885<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5886 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5887</pre>
5888
5889<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5890<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5891 locations, allowing garbage collector implementations that require read
5892 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5893
5894<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5895<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]5896 allocated from the garbage collector. The first object is a pointer to the
5897 start of the referenced object, if needed by the language runtime (otherwise
5898 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5899
5900<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5901<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5902 instruction, but may be replaced with substantially more complex code by the
5903 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5904 may only be used in a function which <a href="#gc">specifies a GC
5905 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5906
5907</div>
5908
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5909<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5910<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5911 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5912</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5913
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5914<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5915
5916<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5917<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5918 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5919</pre>
5920
5921<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5922<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5923 locations, allowing garbage collector implementations that require write
5924 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5925
5926<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5927<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]5928 object to store it to, and the third is the address of the field of Obj to
5929 store to. If the runtime does not require a pointer to the object, Obj may
5930 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5931
5932<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5933<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5934 instruction, but may be replaced with substantially more complex code by the
5935 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5936 may only be used in a function which <a href="#gc">specifies a GC
5937 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5938
5939</div>
5940
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5941</div>
5942
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5943<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5944<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5945 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5946</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5947
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5948<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5949
5950<p>These intrinsics are provided by LLVM to expose special features that may
5951 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5952
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5953<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5954<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5955 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5956</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5957
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5958<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5959
5960<h5>Syntax:</h5>
5961<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5962 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5963</pre>
5964
5965<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5966<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5967 target-specific value indicating the return address of the current function
5968 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5969
5970<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5971<p>The argument to this intrinsic indicates which function to return the address
5972 for. Zero indicates the calling function, one indicates its caller, etc.
5973 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5974
5975<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5976<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5977 indicating the return address of the specified call frame, or zero if it
5978 cannot be identified. The value returned by this intrinsic is likely to be
5979 incorrect or 0 for arguments other than zero, so it should only be used for
5980 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5981
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5982<p>Note that calling this intrinsic does not prevent function inlining or other
5983 aggressive transformations, so the value returned may not be that of the
5984 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5985
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5986</div>
5987
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5988<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5989<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5990 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5991</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5992
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5993<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5994
5995<h5>Syntax:</h5>
5996<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5997 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5998</pre>
5999
6000<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6001<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6002 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6003
6004<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6005<p>The argument to this intrinsic indicates which function to return the frame
6006 pointer for. Zero indicates the calling function, one indicates its caller,
6007 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6008
6009<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6010<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6011 indicating the frame address of the specified call frame, or zero if it
6012 cannot be identified. The value returned by this intrinsic is likely to be
6013 incorrect or 0 for arguments other than zero, so it should only be used for
6014 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6015
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6016<p>Note that calling this intrinsic does not prevent function inlining or other
6017 aggressive transformations, so the value returned may not be that of the
6018 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6019
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6020</div>
6021
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6022<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6023<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6024 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6025</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6026
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6027<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6028
6029<h5>Syntax:</h5>
6030<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6031 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6032</pre>
6033
6034<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6035<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6036 of the function stack, for use
6037 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6038 useful for implementing language features like scoped automatic variable
6039 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6040
6041<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6042<p>This intrinsic returns a opaque pointer value that can be passed
6043 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6044 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6045 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6046 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6047 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6048 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6049
6050</div>
6051
6052<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6053<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6054 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6055</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6056
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6057<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6058
6059<h5>Syntax:</h5>
6060<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6061 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6062</pre>
6063
6064<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6065<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6066 the function stack to the state it was in when the
6067 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6068 executed. This is useful for implementing language features like scoped
6069 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6070
6071<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6072<p>See the description
6073 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6074
6075</div>
6076
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6077<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6078<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6079 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6080</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6081
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6082<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6083
6084<h5>Syntax:</h5>
6085<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6086 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]6087</pre>
6088
6089<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6090<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6091 insert a prefetch instruction if supported; otherwise, it is a noop.
6092 Prefetches have no effect on the behavior of the program but can change its
6093 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6094
6095<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6096<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6097 specifier determining if the fetch should be for a read (0) or write (1),
6098 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6099 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6100 specifies whether the prefetch is performed on the data (1) or instruction (0)
6101 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6102 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6103
6104<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6105<p>This intrinsic does not modify the behavior of the program. In particular,
6106 prefetches cannot trap and do not produce a value. On targets that support
6107 this intrinsic, the prefetch can provide hints to the processor cache for
6108 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6109
6110</div>
6111
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6112<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6113<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6114 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6115</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6116
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6117<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6118
6119<h5>Syntax:</h5>
6120<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6121 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6122</pre>
6123
6124<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6125<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6126 Counter (PC) in a region of code to simulators and other tools. The method
6127 is target specific, but it is expected that the marker will use exported
6128 symbols to transmit the PC of the marker. The marker makes no guarantees
6129 that it will remain with any specific instruction after optimizations. It is
6130 possible that the presence of a marker will inhibit optimizations. The
6131 intended use is to be inserted after optimizations to allow correlations of
6132 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6133
6134<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6135<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6136
6137<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6138<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6139 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6140
6141</div>
6142
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6143<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6144<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6145 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6146</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6147
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6148<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6149
6150<h5>Syntax:</h5>
6151<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6152 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6153</pre>
6154
6155<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6156<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6157 counter register (or similar low latency, high accuracy clocks) on those
6158 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6159 should map to RPCC. As the backing counters overflow quickly (on the order
6160 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6161
6162<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6163<p>When directly supported, reading the cycle counter should not modify any
6164 memory. Implementations are allowed to either return a application specific
6165 value or a system wide value. On backends without support, this is lowered
6166 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6167
6168</div>
6169
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6170</div>
6171
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6172<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6173<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6174 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6175</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6176
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6177<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6178
6179<p>LLVM provides intrinsics for a few important standard C library functions.
6180 These intrinsics allow source-language front-ends to pass information about
6181 the alignment of the pointer arguments to the code generator, providing
6182 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6183
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6184<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6185<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6186 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6187</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6188
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6189<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6190
6191<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6192<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]6193 integer bit width and for different address spaces. Not all targets support
6194 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6195
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6196<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6197 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]6198 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6199 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]6200 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6201</pre>
6202
6203<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6204<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6205 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6206
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6207<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6208 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6209 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6210
6211<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6212
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6213<p>The first argument is a pointer to the destination, the second is a pointer
6214 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6215 number of bytes to copy, the fourth argument is the alignment of the
6216 source and destination locations, and the fifth is a boolean indicating a
6217 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6218
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6219<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]6220 then the caller guarantees that both the source and destination pointers are
6221 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6222
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6223<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6224 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6225 The detailed access behavior is not very cleanly specified and it is unwise
6226 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6227
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6228<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6229
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6230<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6231 source location to the destination location, which are not allowed to
6232 overlap. It copies "len" bytes of memory over. If the argument is known to
6233 be aligned to some boundary, this can be specified as the fourth argument,
6234 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6235
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6236</div>
6237
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6238<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6239<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6240 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6241</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6242
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6243<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6244
6245<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6246<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]6247 width and for different address space. Not all targets support all bit
6248 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6249
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6250<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6251 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]6252 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6253 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]6254 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6255</pre>
6256
6257<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6258<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6259 source location to the destination location. It is similar to the
6260 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6261 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6262
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6263<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6264 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6265 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6266
6267<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6268
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6269<p>The first argument is a pointer to the destination, the second is a pointer
6270 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6271 number of bytes to copy, the fourth argument is the alignment of the
6272 source and destination locations, and the fifth is a boolean indicating a
6273 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6274
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6275<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]6276 then the caller guarantees that the source and destination pointers are
6277 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6278
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6279<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6280 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6281 The detailed access behavior is not very cleanly specified and it is unwise
6282 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6283
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6284<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6285
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6286<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6287 source location to the destination location, which may overlap. It copies
6288 "len" bytes of memory over. If the argument is known to be aligned to some
6289 boundary, this can be specified as the fourth argument, otherwise it should
6290 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6291
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6292</div>
6293
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6294<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6295<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6296 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6297</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6298
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6299<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6300
6301<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6302<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]6303 width and for different address spaces. However, not all targets support all
6304 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6305
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6306<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6307 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6308 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6309 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6310 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6311</pre>
6312
6313<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6314<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6315 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6316
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6317<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6318 intrinsic does not return a value and takes extra alignment/volatile
6319 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6320
6321<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6322<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]6323 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6324 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6325 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6326
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6327<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]6328 then the caller guarantees that the destination pointer is aligned to that
6329 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6330
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6331<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6332 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6333 The detailed access behavior is not very cleanly specified and it is unwise
6334 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6335
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6336<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6337<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6338 at the destination location. If the argument is known to be aligned to some
6339 boundary, this can be specified as the fourth argument, otherwise it should
6340 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6341
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6342</div>
6343
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6344<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6345<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6346 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6347</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6348
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6349<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6350
6351<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6352<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6353 floating point or vector of floating point type. Not all targets support all
6354 types however.</p>
6355
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6356<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6357 declare float @llvm.sqrt.f32(float %Val)
6358 declare double @llvm.sqrt.f64(double %Val)
6359 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6360 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6361 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6362</pre>
6363
6364<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6365<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6366 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6367 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6368 behavior for negative numbers other than -0.0 (which allows for better
6369 optimization, because there is no need to worry about errno being
6370 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]6371
6372<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6373<p>The argument and return value are floating point numbers of the same
6374 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6375
6376<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6377<p>This function returns the sqrt of the specified operand if it is a
6378 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6379
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6380</div>
6381
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6382<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6383<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6384 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6385</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6386
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6387<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6388
6389<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6390<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6391 floating point or vector of floating point type. Not all targets support all
6392 types however.</p>
6393
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6394<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6395 declare float @llvm.powi.f32(float %Val, i32 %power)
6396 declare double @llvm.powi.f64(double %Val, i32 %power)
6397 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6398 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6399 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6400</pre>
6401
6402<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6403<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6404 specified (positive or negative) power. The order of evaluation of
6405 multiplications is not defined. When a vector of floating point type is
6406 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6407
6408<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6409<p>The second argument is an integer power, and the first is a value to raise to
6410 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6411
6412<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6413<p>This function returns the first value raised to the second power with an
6414 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6415
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6416</div>
6417
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6418<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6419<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6420 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6421</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6422
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6423<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6424
6425<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6426<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6427 floating point or vector of floating point type. Not all targets support all
6428 types however.</p>
6429
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6430<pre>
6431 declare float @llvm.sin.f32(float %Val)
6432 declare double @llvm.sin.f64(double %Val)
6433 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6434 declare fp128 @llvm.sin.f128(fp128 %Val)
6435 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6436</pre>
6437
6438<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6439<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6440
6441<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6442<p>The argument and return value are floating point numbers of the same
6443 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6444
6445<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6446<p>This function returns the sine of the specified operand, returning the same
6447 values as the libm <tt>sin</tt> functions would, and handles error conditions
6448 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6449
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6450</div>
6451
6452<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6453<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6454 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6455</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6456
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6457<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6458
6459<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6460<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6461 floating point or vector of floating point type. Not all targets support all
6462 types however.</p>
6463
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6464<pre>
6465 declare float @llvm.cos.f32(float %Val)
6466 declare double @llvm.cos.f64(double %Val)
6467 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6468 declare fp128 @llvm.cos.f128(fp128 %Val)
6469 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6470</pre>
6471
6472<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6473<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6474
6475<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6476<p>The argument and return value are floating point numbers of the same
6477 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6478
6479<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6480<p>This function returns the cosine of the specified operand, returning the same
6481 values as the libm <tt>cos</tt> functions would, and handles error conditions
6482 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6483
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6484</div>
6485
6486<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6487<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6488 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6489</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6490
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6491<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6492
6493<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6494<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6495 floating point or vector of floating point type. Not all targets support all
6496 types however.</p>
6497
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6498<pre>
6499 declare float @llvm.pow.f32(float %Val, float %Power)
6500 declare double @llvm.pow.f64(double %Val, double %Power)
6501 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6502 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6503 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6504</pre>
6505
6506<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6507<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6508 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6509
6510<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6511<p>The second argument is a floating point power, and the first is a value to
6512 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6513
6514<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6515<p>This function returns the first value raised to the second power, returning
6516 the same values as the libm <tt>pow</tt> functions would, and handles error
6517 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6518
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6519</div>
6520
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6521</div>
6522
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6523<!-- _______________________________________________________________________ -->
6524<h4>
6525 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6526</h4>
6527
6528<div>
6529
6530<h5>Syntax:</h5>
6531<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6532 floating point or vector of floating point type. Not all targets support all
6533 types however.</p>
6534
6535<pre>
6536 declare float @llvm.exp.f32(float %Val)
6537 declare double @llvm.exp.f64(double %Val)
6538 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6539 declare fp128 @llvm.exp.f128(fp128 %Val)
6540 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6541</pre>
6542
6543<h5>Overview:</h5>
6544<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6545
6546<h5>Arguments:</h5>
6547<p>The argument and return value are floating point numbers of the same
6548 type.</p>
6549
6550<h5>Semantics:</h5>
6551<p>This function returns the same values as the libm <tt>exp</tt> functions
6552 would, and handles error conditions in the same way.</p>
6553
6554</div>
6555
6556<!-- _______________________________________________________________________ -->
6557<h4>
6558 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6559</h4>
6560
6561<div>
6562
6563<h5>Syntax:</h5>
6564<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6565 floating point or vector of floating point type. Not all targets support all
6566 types however.</p>
6567
6568<pre>
6569 declare float @llvm.log.f32(float %Val)
6570 declare double @llvm.log.f64(double %Val)
6571 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6572 declare fp128 @llvm.log.f128(fp128 %Val)
6573 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6574</pre>
6575
6576<h5>Overview:</h5>
6577<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6578
6579<h5>Arguments:</h5>
6580<p>The argument and return value are floating point numbers of the same
6581 type.</p>
6582
6583<h5>Semantics:</h5>
6584<p>This function returns the same values as the libm <tt>log</tt> functions
6585 would, and handles error conditions in the same way.</p>
6586
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6587<h4>
6588 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6589</h4>
6590
6591<div>
6592
6593<h5>Syntax:</h5>
6594<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6595 floating point or vector of floating point type. Not all targets support all
6596 types however.</p>
6597
6598<pre>
6599 declare float @llvm.fma.f32(float %a, float %b, float %c)
6600 declare double @llvm.fma.f64(double %a, double %b, double %c)
6601 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6602 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6603 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6604</pre>
6605
6606<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]6607<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6608 operation.</p>
6609
6610<h5>Arguments:</h5>
6611<p>The argument and return value are floating point numbers of the same
6612 type.</p>
6613
6614<h5>Semantics:</h5>
6615<p>This function returns the same values as the libm <tt>fma</tt> functions
6616 would.</p>
6617
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6618</div>
6619
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6620<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6621<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6622 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6623</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6624
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6625<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6626
6627<p>LLVM provides intrinsics for a few important bit manipulation operations.
6628 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6629
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6630<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6631<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6632 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6633</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6634
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6635<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6636
6637<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6638<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6639 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6640
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6641<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6642 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6643 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6644 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6645</pre>
6646
6647<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6648<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6649 values with an even number of bytes (positive multiple of 16 bits). These
6650 are useful for performing operations on data that is not in the target's
6651 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6652
6653<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6654<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6655 and low byte of the input i16 swapped. Similarly,
6656 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6657 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6658 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6659 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6660 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6661 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6662
6663</div>
6664
6665<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6666<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6667 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6668</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6669
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6670<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6671
6672<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6673<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]6674 width, or on any vector with integer elements. Not all targets support all
6675 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6676
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6677<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6678 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6679 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6680 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6681 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6682 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6683 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]6684</pre>
6685
6686<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6687<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6688 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6689
6690<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6691<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]6692 integer type, or a vector with integer elements.
6693 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6694
6695<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6696<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6697 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6698
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6699</div>
6700
6701<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6702<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6703 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6704</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6705
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6706<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6707
6708<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6709<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]6710 integer bit width, or any vector whose elements are integers. Not all
6711 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6712
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6713<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6714 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6715 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6716 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6717 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6718 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6719 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]6720</pre>
6721
6722<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6723<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6724 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6725
6726<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6727<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]6728 integer type, or any vector type with integer element type.
6729 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6730
6731<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6732<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6733 zeros in a variable, or within each element of the vector if the operation
6734 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]6735 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6736
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6737</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6738
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6739<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6740<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6741 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6742</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6743
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6744<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6745
6746<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6747<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]6748 integer bit width, or any vector of integer elements. Not all targets
6749 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6750
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6751<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6752 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6753 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6754 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6755 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6756 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6757 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]6758</pre>
6759
6760<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6761<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6762 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6763
6764<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6765<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]6766 integer type, or a vectory with integer element type.. The return type
6767 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6768
6769<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6770<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6771 zeros in a variable, or within each element of a vector.
6772 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6773 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6774
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6775</div>
6776
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6777</div>
6778
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6779<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6780<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6781 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6782</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6783
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6784<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6785
6786<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6787
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6788<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6789<h4>
6790 <a name="int_sadd_overflow">
6791 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6792 </a>
6793</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6794
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6795<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6796
6797<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6798<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]6799 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6800
6801<pre>
6802 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6803 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6804 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6805</pre>
6806
6807<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6808<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6809 a signed addition of the two arguments, and indicate whether an overflow
6810 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6811
6812<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6813<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]6814 be of integer types of any bit width, but they must have the same bit
6815 width. The second element of the result structure must be of
6816 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6817 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6818
6819<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6820<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6821 a signed addition of the two variables. They return a structure &mdash; the
6822 first element of which is the signed summation, and the second element of
6823 which is a bit specifying if the signed summation resulted in an
6824 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6825
6826<h5>Examples:</h5>
6827<pre>
6828 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6829 %sum = extractvalue {i32, i1} %res, 0
6830 %obit = extractvalue {i32, i1} %res, 1
6831 br i1 %obit, label %overflow, label %normal
6832</pre>
6833
6834</div>
6835
6836<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6837<h4>
6838 <a name="int_uadd_overflow">
6839 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6840 </a>
6841</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6842
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6843<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6844
6845<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6846<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]6847 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6848
6849<pre>
6850 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6851 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6852 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6853</pre>
6854
6855<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6856<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6857 an unsigned addition of the two arguments, and indicate whether a carry
6858 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6859
6860<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6861<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]6862 be of integer types of any bit width, but they must have the same bit
6863 width. The second element of the result structure must be of
6864 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6865 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6866
6867<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6868<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6869 an unsigned addition of the two arguments. They return a structure &mdash;
6870 the first element of which is the sum, and the second element of which is a
6871 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6872
6873<h5>Examples:</h5>
6874<pre>
6875 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6876 %sum = extractvalue {i32, i1} %res, 0
6877 %obit = extractvalue {i32, i1} %res, 1
6878 br i1 %obit, label %carry, label %normal
6879</pre>
6880
6881</div>
6882
6883<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6884<h4>
6885 <a name="int_ssub_overflow">
6886 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6887 </a>
6888</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6889
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6890<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6891
6892<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6893<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]6894 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6895
6896<pre>
6897 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6898 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6899 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6900</pre>
6901
6902<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6903<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6904 a signed subtraction of the two arguments, and indicate whether an overflow
6905 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6906
6907<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6908<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]6909 be of integer types of any bit width, but they must have the same bit
6910 width. The second element of the result structure must be of
6911 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6912 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6913
6914<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6915<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6916 a signed subtraction of the two arguments. They return a structure &mdash;
6917 the first element of which is the subtraction, and the second element of
6918 which is a bit specifying if the signed subtraction resulted in an
6919 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6920
6921<h5>Examples:</h5>
6922<pre>
6923 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6924 %sum = extractvalue {i32, i1} %res, 0
6925 %obit = extractvalue {i32, i1} %res, 1
6926 br i1 %obit, label %overflow, label %normal
6927</pre>
6928
6929</div>
6930
6931<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6932<h4>
6933 <a name="int_usub_overflow">
6934 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6935 </a>
6936</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6937
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6938<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6939
6940<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6941<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]6942 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6943
6944<pre>
6945 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6946 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6947 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6948</pre>
6949
6950<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6951<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6952 an unsigned subtraction of the two arguments, and indicate whether an
6953 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6954
6955<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6956<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]6957 be of integer types of any bit width, but they must have the same bit
6958 width. The second element of the result structure must be of
6959 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6960 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6961
6962<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6963<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6964 an unsigned subtraction of the two arguments. They return a structure &mdash;
6965 the first element of which is the subtraction, and the second element of
6966 which is a bit specifying if the unsigned subtraction resulted in an
6967 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6968
6969<h5>Examples:</h5>
6970<pre>
6971 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6972 %sum = extractvalue {i32, i1} %res, 0
6973 %obit = extractvalue {i32, i1} %res, 1
6974 br i1 %obit, label %overflow, label %normal
6975</pre>
6976
6977</div>
6978
6979<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6980<h4>
6981 <a name="int_smul_overflow">
6982 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6983 </a>
6984</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6985
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6986<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6987
6988<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6989<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]6990 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6991
6992<pre>
6993 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6994 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6995 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6996</pre>
6997
6998<h5>Overview:</h5>
6999
7000<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7001 a signed multiplication of the two arguments, and indicate whether an
7002 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7003
7004<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7005<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]7006 be of integer types of any bit width, but they must have the same bit
7007 width. The second element of the result structure must be of
7008 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7009 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7010
7011<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7012<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7013 a signed multiplication of the two arguments. They return a structure &mdash;
7014 the first element of which is the multiplication, and the second element of
7015 which is a bit specifying if the signed multiplication resulted in an
7016 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7017
7018<h5>Examples:</h5>
7019<pre>
7020 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7021 %sum = extractvalue {i32, i1} %res, 0
7022 %obit = extractvalue {i32, i1} %res, 1
7023 br i1 %obit, label %overflow, label %normal
7024</pre>
7025
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7026</div>
7027
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7028<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7029<h4>
7030 <a name="int_umul_overflow">
7031 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7032 </a>
7033</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7034
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7035<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7036
7037<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7038<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]7039 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7040
7041<pre>
7042 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7043 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7044 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7045</pre>
7046
7047<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7048<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7049 a unsigned multiplication of the two arguments, and indicate whether an
7050 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7051
7052<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7053<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]7054 be of integer types of any bit width, but they must have the same bit
7055 width. The second element of the result structure must be of
7056 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7057 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7058
7059<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7060<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7061 an unsigned multiplication of the two arguments. They return a structure
7062 &mdash; the first element of which is the multiplication, and the second
7063 element of which is a bit specifying if the unsigned multiplication resulted
7064 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7065
7066<h5>Examples:</h5>
7067<pre>
7068 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7069 %sum = extractvalue {i32, i1} %res, 0
7070 %obit = extractvalue {i32, i1} %res, 1
7071 br i1 %obit, label %overflow, label %normal
7072</pre>
7073
7074</div>
7075
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7076</div>
7077
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7078<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7079<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7080 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7081</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7082
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7083<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7084
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7085<p>Half precision floating point is a storage-only format. This means that it is
7086 a dense encoding (in memory) but does not support computation in the
7087 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7088
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7089<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7090 value as an i16, then convert it to float with <a
7091 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7092 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7093 double etc). To store the value back to memory, it is first converted to
7094 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7095 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7096 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7097
7098<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7099<h4>
7100 <a name="int_convert_to_fp16">
7101 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7102 </a>
7103</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7104
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7105<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7106
7107<h5>Syntax:</h5>
7108<pre>
7109 declare i16 @llvm.convert.to.fp16(f32 %a)
7110</pre>
7111
7112<h5>Overview:</h5>
7113<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7114 a conversion from single precision floating point format to half precision
7115 floating point format.</p>
7116
7117<h5>Arguments:</h5>
7118<p>The intrinsic function contains single argument - the value to be
7119 converted.</p>
7120
7121<h5>Semantics:</h5>
7122<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7123 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7124 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7125 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7126
7127<h5>Examples:</h5>
7128<pre>
7129 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7130 store i16 %res, i16* @x, align 2
7131</pre>
7132
7133</div>
7134
7135<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7136<h4>
7137 <a name="int_convert_from_fp16">
7138 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7139 </a>
7140</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7141
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7142<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7143
7144<h5>Syntax:</h5>
7145<pre>
7146 declare f32 @llvm.convert.from.fp16(i16 %a)
7147</pre>
7148
7149<h5>Overview:</h5>
7150<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7151 a conversion from half precision floating point format to single precision
7152 floating point format.</p>
7153
7154<h5>Arguments:</h5>
7155<p>The intrinsic function contains single argument - the value to be
7156 converted.</p>
7157
7158<h5>Semantics:</h5>
7159<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7160 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7161 precision floating point format. The input half-float value is represented by
7162 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7163
7164<h5>Examples:</h5>
7165<pre>
7166 %a = load i16* @x, align 2
7167 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7168</pre>
7169
7170</div>
7171
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7172</div>
7173
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7174<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7175<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7176 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7177</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7178
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7179<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7180
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7181<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7182 prefix), are described in
7183 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7184 Level Debugging</a> document.</p>
7185
7186</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7187
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7188<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7189<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7190 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7191</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7192
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7193<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7194
7195<p>The LLVM exception handling intrinsics (which all start with
7196 <tt>llvm.eh.</tt> prefix), are described in
7197 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7198 Handling</a> document.</p>
7199
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7200</div>
7201
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7202<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7203<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7204 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7205</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7206
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7207<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7208
7209<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7210 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7211 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7212 function pointer lacking the nest parameter - the caller does not need to
7213 provide a value for it. Instead, the value to use is stored in advance in a
7214 "trampoline", a block of memory usually allocated on the stack, which also
7215 contains code to splice the nest value into the argument list. This is used
7216 to implement the GCC nested function address extension.</p>
7217
7218<p>For example, if the function is
7219 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7220 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7221 follows:</p>
7222
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7223<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7224 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7225 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7226 %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]7227 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7228</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7229
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7230<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7231 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7232
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7233<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7234<h4>
7235 <a name="int_it">
7236 '<tt>llvm.init.trampoline</tt>' Intrinsic
7237 </a>
7238</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7239
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7240<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7241
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7242<h5>Syntax:</h5>
7243<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7244 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]7245</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7246
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7247<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7248<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7249 function pointer suitable for executing it.</p>
7250
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7251<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7252<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7253 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7254 sufficiently aligned block of memory; this memory is written to by the
7255 intrinsic. Note that the size and the alignment are target-specific - LLVM
7256 currently provides no portable way of determining them, so a front-end that
7257 generates this intrinsic needs to have some target-specific knowledge.
7258 The <tt>func</tt> argument must hold a function bitcast to
7259 an <tt>i8*</tt>.</p>
7260
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7261<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7262<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7263 dependent code, turning it into a function. A pointer to this function is
7264 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7265 function pointer type</a> before being called. The new function's signature
7266 is the same as that of <tt>func</tt> with any arguments marked with
7267 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7268 is allowed, and it must be of pointer type. Calling the new function is
7269 equivalent to calling <tt>func</tt> with the same argument list, but
7270 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7271 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7272 by <tt>tramp</tt> is modified, then the effect of any later call to the
7273 returned function pointer is undefined.</p>
7274
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7275</div>
7276
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7277</div>
7278
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7279<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7280<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7281 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7282</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7283
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7284<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7285
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7286<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7287 hardware constructs for atomic operations and memory synchronization. This
7288 provides an interface to the hardware, not an interface to the programmer. It
7289 is aimed at a low enough level to allow any programming models or APIs
7290 (Application Programming Interfaces) which need atomic behaviors to map
7291 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7292 hardware provides a "universal IR" for source languages, it also provides a
7293 starting point for developing a "universal" atomic operation and
7294 synchronization IR.</p>
7295
7296<p>These do <em>not</em> form an API such as high-level threading libraries,
7297 software transaction memory systems, atomic primitives, and intrinsic
7298 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7299 application libraries. The hardware interface provided by LLVM should allow
7300 a clean implementation of all of these APIs and parallel programming models.
7301 No one model or paradigm should be selected above others unless the hardware
7302 itself ubiquitously does so.</p>
7303
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7304<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7305<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7306 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7307</h4>
7308
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7309<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7310<h5>Syntax:</h5>
7311<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7312 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]7313</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7314
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7315<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7316<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7317 specific pairs of memory access types.</p>
7318
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7319<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7320<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7321 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7322 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7323 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7324
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7325<ul>
7326 <li><tt>ll</tt>: load-load barrier</li>
7327 <li><tt>ls</tt>: load-store barrier</li>
7328 <li><tt>sl</tt>: store-load barrier</li>
7329 <li><tt>ss</tt>: store-store barrier</li>
7330 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7331</ul>
7332
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7333<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7334<p>This intrinsic causes the system to enforce some ordering constraints upon
7335 the loads and stores of the program. This barrier does not
7336 indicate <em>when</em> any events will occur, it only enforces
7337 an <em>order</em> in which they occur. For any of the specified pairs of load
7338 and store operations (f.ex. load-load, or store-load), all of the first
7339 operations preceding the barrier will complete before any of the second
7340 operations succeeding the barrier begin. Specifically the semantics for each
7341 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7342
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7343<ul>
7344 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7345 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7346 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7347 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7348 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7349 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7350 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7351 load after the barrier begins.</li>
7352</ul>
7353
7354<p>These semantics are applied with a logical "and" behavior when more than one
7355 is enabled in a single memory barrier intrinsic.</p>
7356
7357<p>Backends may implement stronger barriers than those requested when they do
7358 not support as fine grained a barrier as requested. Some architectures do
7359 not need all types of barriers and on such architectures, these become
7360 noops.</p>
7361
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7362<h5>Example:</h5>
7363<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7364%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7365%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7366 store i32 4, %ptr
7367
7368%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7369 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]7370 <i>; guarantee the above finishes</i>
7371 store i32 8, %ptr <i>; before this begins</i>
7372</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7373
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7374</div>
7375
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7376<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7377<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7378 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7379</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7380
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7381<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7382
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7383<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7384<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7385 any integer bit width and for different address spaces. Not all targets
7386 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7387
7388<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7389 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7390 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7391 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7392 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]7393</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7394
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7395<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7396<p>This loads a value in memory and compares it to a given value. If they are
7397 equal, it stores a new value into the memory.</p>
7398
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7399<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7400<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7401 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7402 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7403 this integer type. While any bit width integer may be used, targets may only
7404 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7405
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7406<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7407<p>This entire intrinsic must be executed atomically. It first loads the value
7408 in memory pointed to by <tt>ptr</tt> and compares it with the
7409 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7410 memory. The loaded value is yielded in all cases. This provides the
7411 equivalent of an atomic compare-and-swap operation within the SSA
7412 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7413
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7414<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7415<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7416%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7417%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7418 store i32 4, %ptr
7419
7420%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7421%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7422 <i>; yields {i32}:result1 = 4</i>
7423%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7424%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7425
7426%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7427%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7428 <i>; yields {i32}:result2 = 8</i>
7429%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7430
7431%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7432</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7433
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7434</div>
7435
7436<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7437<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7438 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7439</h4>
7440
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7441<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7442<h5>Syntax:</h5>
7443
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7444<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7445 integer bit width. Not all targets support all bit widths however.</p>
7446
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7447<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7448 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7449 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7450 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7451 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]7452</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7453
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7454<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7455<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7456 the value from memory. It then stores the value in <tt>val</tt> in the memory
7457 at <tt>ptr</tt>.</p>
7458
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7459<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7460<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7461 the <tt>val</tt> argument and the result must be integers of the same bit
7462 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7463 integer type. The targets may only lower integer representations they
7464 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7465
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7466<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7467<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7468 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7469 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7470
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7471<h5>Examples:</h5>
7472<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7473%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7474%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7475 store i32 4, %ptr
7476
7477%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7478%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7479 <i>; yields {i32}:result1 = 4</i>
7480%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7481%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7482
7483%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7484%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7485 <i>; yields {i32}:result2 = 8</i>
7486
7487%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7488%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7489</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7490
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7491</div>
7492
7493<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7494<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7495 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7496</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7497
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7498<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7499
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7500<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7501<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7502 any integer bit width. Not all targets support all bit widths however.</p>
7503
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7504<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7505 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7506 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7507 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7508 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]7509</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7510
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7511<h5>Overview:</h5>
7512<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7513 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7514
7515<h5>Arguments:</h5>
7516<p>The intrinsic takes two arguments, the first a pointer to an integer value
7517 and the second an integer value. The result is also an integer value. These
7518 integer types can have any bit width, but they must all have the same bit
7519 width. The targets may only lower integer representations they support.</p>
7520
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7521<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7522<p>This intrinsic does a series of operations atomically. It first loads the
7523 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7524 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]7525
7526<h5>Examples:</h5>
7527<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7528%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7529%ptr = bitcast i8* %mallocP to i32*
7530 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7531%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7532 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7533%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7534 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7535%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7536 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7537%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7538</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7539
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7540</div>
7541
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7542<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7543<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7544 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7545</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7546
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7547<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7548
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7549<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7550<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7551 any integer bit width and for different address spaces. Not all targets
7552 support all bit widths however.</p>
7553
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7554<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7555 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7556 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7557 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7558 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]7559</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7560
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7561<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7562<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7563 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7564
7565<h5>Arguments:</h5>
7566<p>The intrinsic takes two arguments, the first a pointer to an integer value
7567 and the second an integer value. The result is also an integer value. These
7568 integer types can have any bit width, but they must all have the same bit
7569 width. The targets may only lower integer representations they support.</p>
7570
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7571<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7572<p>This intrinsic does a series of operations atomically. It first loads the
7573 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7574 result to <tt>ptr</tt>. It yields the original value stored
7575 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7576
7577<h5>Examples:</h5>
7578<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7579%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7580%ptr = bitcast i8* %mallocP to i32*
7581 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7582%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7583 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7584%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7585 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7586%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7587 <i>; yields {i32}:result3 = 2</i>
7588%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7589</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7590
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7591</div>
7592
7593<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7594<h4>
7595 <a name="int_atomic_load_and">
7596 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7597 </a>
7598 <br>
7599 <a name="int_atomic_load_nand">
7600 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7601 </a>
7602 <br>
7603 <a name="int_atomic_load_or">
7604 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7605 </a>
7606 <br>
7607 <a name="int_atomic_load_xor">
7608 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7609 </a>
7610</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7611
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7612<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7613
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7614<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7615<p>These are overloaded intrinsics. You can
7616 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7617 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7618 bit width and for different address spaces. Not all targets support all bit
7619 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7620
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7621<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7622 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7623 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7624 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7625 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]7626</pre>
7627
7628<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7629 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7630 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7631 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7632 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]7633</pre>
7634
7635<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7636 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7637 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7638 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7639 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]7640</pre>
7641
7642<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7643 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7644 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7645 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7646 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]7647</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7648
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7649<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7650<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7651 the value stored in memory at <tt>ptr</tt>. It yields the original value
7652 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7653
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7654<h5>Arguments:</h5>
7655<p>These intrinsics take two arguments, the first a pointer to an integer value
7656 and the second an integer value. The result is also an integer value. These
7657 integer types can have any bit width, but they must all have the same bit
7658 width. The targets may only lower integer representations they support.</p>
7659
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7660<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7661<p>These intrinsics does a series of operations atomically. They first load the
7662 value stored at <tt>ptr</tt>. They then do the bitwise
7663 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7664 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7665
7666<h5>Examples:</h5>
7667<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7668%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7669%ptr = bitcast i8* %mallocP to i32*
7670 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7671%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7672 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7673%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7674 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7675%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7676 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7677%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7678 <i>; yields {i32}:result3 = FF</i>
7679%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7680</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7681
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7682</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7683
7684<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7685<h4>
7686 <a name="int_atomic_load_max">
7687 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7688 </a>
7689 <br>
7690 <a name="int_atomic_load_min">
7691 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7692 </a>
7693 <br>
7694 <a name="int_atomic_load_umax">
7695 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7696 </a>
7697 <br>
7698 <a name="int_atomic_load_umin">
7699 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7700 </a>
7701</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7702
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7703<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7704
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7705<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7706<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7707 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7708 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7709 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7710
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7711<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7712 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7713 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7714 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7715 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]7716</pre>
7717
7718<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7719 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7720 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7721 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7722 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]7723</pre>
7724
7725<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7726 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7727 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7728 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7729 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]7730</pre>
7731
7732<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7733 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7734 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7735 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7736 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]7737</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7738
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7739<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7740<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7741 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7742 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7743
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7744<h5>Arguments:</h5>
7745<p>These intrinsics take two arguments, the first a pointer to an integer value
7746 and the second an integer value. The result is also an integer value. These
7747 integer types can have any bit width, but they must all have the same bit
7748 width. The targets may only lower integer representations they support.</p>
7749
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7750<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7751<p>These intrinsics does a series of operations atomically. They first load the
7752 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7753 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7754 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7755
7756<h5>Examples:</h5>
7757<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7758%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7759%ptr = bitcast i8* %mallocP to i32*
7760 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7761%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7762 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7763%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7764 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7765%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7766 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7767%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7768 <i>; yields {i32}:result3 = 8</i>
7769%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7770</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7771
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7772</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7773
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7774</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7775
7776<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7777<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7778 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7779</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7780
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7781<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7782
7783<p>This class of intrinsics exists to information about the lifetime of memory
7784 objects and ranges where variables are immutable.</p>
7785
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7786<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7787<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7788 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7789</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7790
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7791<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7792
7793<h5>Syntax:</h5>
7794<pre>
7795 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7796</pre>
7797
7798<h5>Overview:</h5>
7799<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7800 object's lifetime.</p>
7801
7802<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7803<p>The first argument is a constant integer representing the size of the
7804 object, or -1 if it is variable sized. The second argument is a pointer to
7805 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7806
7807<h5>Semantics:</h5>
7808<p>This intrinsic indicates that before this point in the code, the value of the
7809 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]7810 never be used and has an undefined value. A load from the pointer that
7811 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7812 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7813
7814</div>
7815
7816<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7817<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7818 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7819</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7820
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7821<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7822
7823<h5>Syntax:</h5>
7824<pre>
7825 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7826</pre>
7827
7828<h5>Overview:</h5>
7829<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7830 object's lifetime.</p>
7831
7832<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7833<p>The first argument is a constant integer representing the size of the
7834 object, or -1 if it is variable sized. The second argument is a pointer to
7835 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7836
7837<h5>Semantics:</h5>
7838<p>This intrinsic indicates that after this point in the code, the value of the
7839 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7840 never be used and has an undefined value. Any stores into the memory object
7841 following this intrinsic may be removed as dead.
7842
7843</div>
7844
7845<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7846<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7847 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7848</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7849
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7850<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7851
7852<h5>Syntax:</h5>
7853<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]7854 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7855</pre>
7856
7857<h5>Overview:</h5>
7858<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7859 a memory object will not change.</p>
7860
7861<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7862<p>The first argument is a constant integer representing the size of the
7863 object, or -1 if it is variable sized. The second argument is a pointer to
7864 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7865
7866<h5>Semantics:</h5>
7867<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7868 the return value, the referenced memory location is constant and
7869 unchanging.</p>
7870
7871</div>
7872
7873<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7874<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7875 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7876</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7877
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7878<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7879
7880<h5>Syntax:</h5>
7881<pre>
7882 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7883</pre>
7884
7885<h5>Overview:</h5>
7886<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7887 a memory object are mutable.</p>
7888
7889<h5>Arguments:</h5>
7890<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7891 The second argument is a constant integer representing the size of the
7892 object, or -1 if it is variable sized and the third argument is a pointer
7893 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7894
7895<h5>Semantics:</h5>
7896<p>This intrinsic indicates that the memory is mutable again.</p>
7897
7898</div>
7899
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7900</div>
7901
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7902<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7903<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7904 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7905</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7906
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7907<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7908
7909<p>This class of intrinsics is designed to be generic and has no specific
7910 purpose.</p>
7911
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7912<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7913<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7914 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7915</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7916
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7917<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7918
7919<h5>Syntax:</h5>
7920<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7921 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]7922</pre>
7923
7924<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7925<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7926
7927<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7928<p>The first argument is a pointer to a value, the second is a pointer to a
7929 global string, the third is a pointer to a global string which is the source
7930 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7931
7932<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7933<p>This intrinsic allows annotation of local variables with arbitrary strings.
7934 This can be useful for special purpose optimizations that want to look for
7935 these annotations. These have no other defined use, they are ignored by code
7936 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7937
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7938</div>
7939
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7940<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7941<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7942 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7943</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7944
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7945<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7946
7947<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7948<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7949 any integer bit width.</p>
7950
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7951<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7952 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7953 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7954 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7955 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7956 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]7957</pre>
7958
7959<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7960<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7961
7962<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7963<p>The first argument is an integer value (result of some expression), the
7964 second is a pointer to a global string, the third is a pointer to a global
7965 string which is the source file name, and the last argument is the line
7966 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7967
7968<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7969<p>This intrinsic allows annotations to be put on arbitrary expressions with
7970 arbitrary strings. This can be useful for special purpose optimizations that
7971 want to look for these annotations. These have no other defined use, they
7972 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7973
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7974</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7975
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7976<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7977<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7978 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7979</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7980
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7981<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7982
7983<h5>Syntax:</h5>
7984<pre>
7985 declare void @llvm.trap()
7986</pre>
7987
7988<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7989<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7990
7991<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7992<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7993
7994<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7995<p>This intrinsics is lowered to the target dependent trap instruction. If the
7996 target does not have a trap instruction, this intrinsic will be lowered to
7997 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7998
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7999</div>
8000
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8001<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8002<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]8003 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8004</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8005
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8006<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8007
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8008<h5>Syntax:</h5>
8009<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8010 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8011</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8012
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8013<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8014<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8015 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8016 ensure that it is placed on the stack before local variables.</p>
8017
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8018<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8019<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8020 arguments. The first argument is the value loaded from the stack
8021 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8022 that has enough space to hold the value of the guard.</p>
8023
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8024<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8025<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8026 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8027 stack. This is to ensure that if a local variable on the stack is
8028 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8029 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8030 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8031 function.</p>
8032
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8033</div>
8034
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8035<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8036<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8037 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8038</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8039
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8040<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8041
8042<h5>Syntax:</h5>
8043<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8044 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8045 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8046</pre>
8047
8048<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8049<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8050 the optimizers to determine at compile time whether a) an operation (like
8051 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8052 runtime check for overflow isn't necessary. An object in this context means
8053 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8054
8055<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8056<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8057 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8058 is a boolean 0 or 1. This argument determines whether you want the
8059 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]8060 1, variables are not allowed.</p>
8061
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8062<h5>Semantics:</h5>
8063<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8064 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8065 depending on the <tt>type</tt> argument, if the size cannot be determined at
8066 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8067
8068</div>
8069
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8070</div>
8071
8072</div>
8073
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8074<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8075<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8076<address>
8077 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8078 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8079 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8080 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8081
8082 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8083 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8084 Last modified: $Date$
8085</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8086
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8087</body>
8088</html>