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gerrit-public.fairphone.software / toolchain / llvm-project / 6651b33671c2bc76e7cc82a387842a007e185267 / . / 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>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]57 <li><a href="#ordering">Atomic Memory Ordering Constraints</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]58 </ol>
59 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]60 <li><a href="#typesystem">Type System</a>
61 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]63 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]64 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]65 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]67 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]68 <li><a href="#t_void">Void Type</a></li>
69 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]70 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#t_derived">Derived Types</a>
74 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]75 <li><a href="#t_aggregate">Aggregate Types</a>
76 <ol>
77 <li><a href="#t_array">Array Type</a></li>
78 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]79 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]80 <li><a href="#t_vector">Vector Type</a></li>
81 </ol>
82 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]83 <li><a href="#t_function">Function Type</a></li>
84 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
87 </ol>
88 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
94 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]95 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]104 </ol>
105 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]106 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
107 <ol>
108 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]109 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
110 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]111 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
112 Global Variable</a></li>
113 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
114 Global Variable</a></li>
115 </ol>
116 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#instref">Instruction Reference</a>
118 <ol>
119 <li><a href="#terminators">Terminator Instructions</a>
120 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
122 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]124 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]125 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]127 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]128 </ol>
129 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]130 <li><a href="#binaryops">Binary Operations</a>
131 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]136 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]137 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]138 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
139 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
140 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]141 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
142 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
143 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]144 </ol>
145 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]146 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
147 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]148 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
149 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
150 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]152 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]153 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]154 </ol>
155 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]156 <li><a href="#vectorops">Vector Operations</a>
157 <ol>
158 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
159 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
160 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]161 </ol>
162 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]163 <li><a href="#aggregateops">Aggregate Operations</a>
164 <ol>
165 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
166 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
167 </ol>
168 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]169 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]170 <ol>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]171 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
172 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
173 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
174 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
175 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
176 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]177 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]178 </ol>
179 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]180 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]181 <ol>
182 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
183 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
184 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
185 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
186 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]187 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
188 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
189 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
190 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]191 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
192 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]193 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]194 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]195 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]196 <li><a href="#otherops">Other Operations</a>
197 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]198 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
199 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]200 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]201 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]202 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]203 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]204 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]205 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]206 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]207 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]208 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]209 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]210 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
211 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]212 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
213 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
214 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]215 </ol>
216 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]217 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
218 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]219 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
220 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
221 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]222 </ol>
223 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]224 <li><a href="#int_codegen">Code Generator Intrinsics</a>
225 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]226 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
227 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
228 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
229 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
230 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
231 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]232 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]233 </ol>
234 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]235 <li><a href="#int_libc">Standard C Library Intrinsics</a>
236 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]237 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]242 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
243 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
244 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]245 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
246 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]247 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]248 </ol>
249 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]250 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]251 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]252 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]253 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
254 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
255 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]256 </ol>
257 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]258 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
259 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]260 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
261 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
262 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
263 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
264 <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]265 <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]266 </ol>
267 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]268 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
269 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]270 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
271 <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]272 </ol>
273 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]274 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]275 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]276 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]277 <ol>
278 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]279 </ol>
280 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]281 <li><a href="#int_atomics">Atomic intrinsics</a>
282 <ol>
283 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
284 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
285 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
286 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
287 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
288 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
289 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
290 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
291 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
292 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
293 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
294 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
295 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
296 </ol>
297 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]298 <li><a href="#int_memorymarkers">Memory Use Markers</a>
299 <ol>
300 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
301 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
302 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
303 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
304 </ol>
305 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]306 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]307 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]308 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]310 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]311 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]312 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]313 '<tt>llvm.trap</tt>' Intrinsic</a></li>
314 <li><a href="#int_stackprotector">
315 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]316 <li><a href="#int_objectsize">
317 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]318 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]319 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]320 </ol>
321 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]322</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]323
324<div class="doc_author">
325 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
326 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]327</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]328
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]329<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]330<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]331<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]332
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]333<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]334
335<p>This document is a reference manual for the LLVM assembly language. LLVM is
336 a Static Single Assignment (SSA) based representation that provides type
337 safety, low-level operations, flexibility, and the capability of representing
338 'all' high-level languages cleanly. It is the common code representation
339 used throughout all phases of the LLVM compilation strategy.</p>
340
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]341</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]342
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]343<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]344<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]345<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]346
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]347<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]348
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]349<p>The LLVM code representation is designed to be used in three different forms:
350 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
351 for fast loading by a Just-In-Time compiler), and as a human readable
352 assembly language representation. This allows LLVM to provide a powerful
353 intermediate representation for efficient compiler transformations and
354 analysis, while providing a natural means to debug and visualize the
355 transformations. The three different forms of LLVM are all equivalent. This
356 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]357
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]358<p>The LLVM representation aims to be light-weight and low-level while being
359 expressive, typed, and extensible at the same time. It aims to be a
360 "universal IR" of sorts, by being at a low enough level that high-level ideas
361 may be cleanly mapped to it (similar to how microprocessors are "universal
362 IR's", allowing many source languages to be mapped to them). By providing
363 type information, LLVM can be used as the target of optimizations: for
364 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]365 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]366 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]367
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]368<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]369<h4>
370 <a name="wellformed">Well-Formedness</a>
371</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]372
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]373<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]374
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]375<p>It is important to note that this document describes 'well formed' LLVM
376 assembly language. There is a difference between what the parser accepts and
377 what is considered 'well formed'. For example, the following instruction is
378 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]379
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]380<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]381%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]382</pre>
383
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]384<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
385 LLVM infrastructure provides a verification pass that may be used to verify
386 that an LLVM module is well formed. This pass is automatically run by the
387 parser after parsing input assembly and by the optimizer before it outputs
388 bitcode. The violations pointed out by the verifier pass indicate bugs in
389 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]390
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]391</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]392
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]393</div>
394
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]395<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]396
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]397<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]398<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]399<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]400
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]401<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]402
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]403<p>LLVM identifiers come in two basic types: global and local. Global
404 identifiers (functions, global variables) begin with the <tt>'@'</tt>
405 character. Local identifiers (register names, types) begin with
406 the <tt>'%'</tt> character. Additionally, there are three different formats
407 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]408
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]409<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]410 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]411 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
412 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
413 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
414 other characters in their names can be surrounded with quotes. Special
415 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
416 ASCII code for the character in hexadecimal. In this way, any character
417 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]418
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]419 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]420 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]422 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]423 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]424</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]425
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]426<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]427 don't need to worry about name clashes with reserved words, and the set of
428 reserved words may be expanded in the future without penalty. Additionally,
429 unnamed identifiers allow a compiler to quickly come up with a temporary
430 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]431
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]432<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]433 languages. There are keywords for different opcodes
434 ('<tt><a href="#i_add">add</a></tt>',
435 '<tt><a href="#i_bitcast">bitcast</a></tt>',
436 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
437 ('<tt><a href="#t_void">void</a></tt>',
438 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
439 reserved words cannot conflict with variable names, because none of them
440 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]441
442<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]443 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]445<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]447<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]448%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]449</pre>
450
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]451<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]452
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]453<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]454%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]455</pre>
456
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]457<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]458
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]459<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]460%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
461%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]462%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]463</pre>
464
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]465<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
466 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]468<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]469 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]470 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]471
472 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]473 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]474
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]475 <li>Unnamed temporaries are numbered sequentially</li>
476</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]477
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]478<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]479 demonstrating instructions, we will follow an instruction with a comment that
480 defines the type and name of value produced. Comments are shown in italic
481 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]482
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]483</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]484
485<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]486<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]487<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]488<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]490<h3>
491 <a name="modulestructure">Module Structure</a>
492</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]493
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]494<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]495
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]496<p>LLVM programs are composed of "Module"s, each of which is a translation unit
497 of the input programs. Each module consists of functions, global variables,
498 and symbol table entries. Modules may be combined together with the LLVM
499 linker, which merges function (and global variable) definitions, resolves
500 forward declarations, and merges symbol table entries. Here is an example of
501 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]503<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]504<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]505<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]506
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]507<i>; External declaration of the puts function</i>&nbsp;
508<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]509
510<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]511define i32 @main() { <i>; i32()* </i>&nbsp;
512 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
513 %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]514
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]515 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
516 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
517 <a href="#i_ret">ret</a> i32 0&nbsp;
518}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]519
520<i>; Named metadata</i>
521!1 = metadata !{i32 41}
522!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]523</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]524
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]525<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]526 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]527 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]528 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
529 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]530
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]531<p>In general, a module is made up of a list of global values, where both
532 functions and global variables are global values. Global values are
533 represented by a pointer to a memory location (in this case, a pointer to an
534 array of char, and a pointer to a function), and have one of the
535 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]536
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]537</div>
538
539<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]540<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]541 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]542</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]543
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]544<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]545
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]546<p>All Global Variables and Functions have one of the following types of
547 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]548
549<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]550 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]551 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
552 by objects in the current module. In particular, linking code into a
553 module with an private global value may cause the private to be renamed as
554 necessary to avoid collisions. Because the symbol is private to the
555 module, all references can be updated. This doesn't show up in any symbol
556 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]557
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]558 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]559 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
560 assembler and evaluated by the linker. Unlike normal strong symbols, they
561 are removed by the linker from the final linked image (executable or
562 dynamic library).</dd>
563
564 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
565 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
566 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
567 linker. The symbols are removed by the linker from the final linked image
568 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]569
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]570 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
571 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
572 of the object is not taken. For instance, functions that had an inline
573 definition, but the compiler decided not to inline it. Note,
574 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
575 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
576 visibility. The symbols are removed by the linker from the final linked
577 image (executable or dynamic library).</dd>
578
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]579 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]580 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]581 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
582 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]583
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]584 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]585 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]586 into the object file corresponding to the LLVM module. They exist to
587 allow inlining and other optimizations to take place given knowledge of
588 the definition of the global, which is known to be somewhere outside the
589 module. Globals with <tt>available_externally</tt> linkage are allowed to
590 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
591 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]592
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]593 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]594 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]595 the same name when linkage occurs. This can be used to implement
596 some forms of inline functions, templates, or other code which must be
597 generated in each translation unit that uses it, but where the body may
598 be overridden with a more definitive definition later. Unreferenced
599 <tt>linkonce</tt> globals are allowed to be discarded. Note that
600 <tt>linkonce</tt> linkage does not actually allow the optimizer to
601 inline the body of this function into callers because it doesn't know if
602 this definition of the function is the definitive definition within the
603 program or whether it will be overridden by a stronger definition.
604 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
605 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]606
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]607 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]608 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
609 <tt>linkonce</tt> linkage, except that unreferenced globals with
610 <tt>weak</tt> linkage may not be discarded. This is used for globals that
611 are declared "weak" in C source code.</dd>
612
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]613 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]614 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
615 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
616 global scope.
617 Symbols with "<tt>common</tt>" linkage are merged in the same way as
618 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]619 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]620 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]621 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
622 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]623
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]624
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]625 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]626 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]627 pointer to array type. When two global variables with appending linkage
628 are linked together, the two global arrays are appended together. This is
629 the LLVM, typesafe, equivalent of having the system linker append together
630 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]631
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]632 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]633 <dd>The semantics of this linkage follow the ELF object file model: the symbol
634 is weak until linked, if not linked, the symbol becomes null instead of
635 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]636
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]637 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
638 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]639 <dd>Some languages allow differing globals to be merged, such as two functions
640 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]641 that only equivalent globals are ever merged (the "one definition rule"
642 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]643 and <tt>weak_odr</tt> linkage types to indicate that the global will only
644 be merged with equivalent globals. These linkage types are otherwise the
645 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]646
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]647 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]648 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]649 visible, meaning that it participates in linkage and can be used to
650 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]651</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]653<p>The next two types of linkage are targeted for Microsoft Windows platform
654 only. They are designed to support importing (exporting) symbols from (to)
655 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]656
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]657<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]658 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]659 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]660 or variable via a global pointer to a pointer that is set up by the DLL
661 exporting the symbol. On Microsoft Windows targets, the pointer name is
662 formed by combining <code>__imp_</code> and the function or variable
663 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]664
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]665 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]666 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]667 pointer to a pointer in a DLL, so that it can be referenced with the
668 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
669 name is formed by combining <code>__imp_</code> and the function or
670 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]671</dl>
672
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]673<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
674 another module defined a "<tt>.LC0</tt>" variable and was linked with this
675 one, one of the two would be renamed, preventing a collision. Since
676 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
677 declarations), they are accessible outside of the current module.</p>
678
679<p>It is illegal for a function <i>declaration</i> to have any linkage type
680 other than "externally visible", <tt>dllimport</tt>
681 or <tt>extern_weak</tt>.</p>
682
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]683<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]684 or <tt>weak_odr</tt> linkages.</p>
685
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]686</div>
687
688<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]689<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]690 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]691</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]692
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]693<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]694
695<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]696 and <a href="#i_invoke">invokes</a> can all have an optional calling
697 convention specified for the call. The calling convention of any pair of
698 dynamic caller/callee must match, or the behavior of the program is
699 undefined. The following calling conventions are supported by LLVM, and more
700 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]701
702<dl>
703 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]704 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]705 specified) matches the target C calling conventions. This calling
706 convention supports varargs function calls and tolerates some mismatch in
707 the declared prototype and implemented declaration of the function (as
708 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]709
710 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]711 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]712 (e.g. by passing things in registers). This calling convention allows the
713 target to use whatever tricks it wants to produce fast code for the
714 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]715 (Application Binary Interface).
716 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]717 when this or the GHC convention is used.</a> This calling convention
718 does not support varargs and requires the prototype of all callees to
719 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]720
721 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]722 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]723 as possible under the assumption that the call is not commonly executed.
724 As such, these calls often preserve all registers so that the call does
725 not break any live ranges in the caller side. This calling convention
726 does not support varargs and requires the prototype of all callees to
727 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]728
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]729 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
730 <dd>This calling convention has been implemented specifically for use by the
731 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
732 It passes everything in registers, going to extremes to achieve this by
733 disabling callee save registers. This calling convention should not be
734 used lightly but only for specific situations such as an alternative to
735 the <em>register pinning</em> performance technique often used when
736 implementing functional programming languages.At the moment only X86
737 supports this convention and it has the following limitations:
738 <ul>
739 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
740 floating point types are supported.</li>
741 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
742 6 floating point parameters.</li>
743 </ul>
744 This calling convention supports
745 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
746 requires both the caller and callee are using it.
747 </dd>
748
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]749 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]750 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]751 target-specific calling conventions to be used. Target specific calling
752 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]753</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]754
755<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]756 support Pascal conventions or any other well-known target-independent
757 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]758
759</div>
760
761<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]762<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]764</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]765
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]766<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]767
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]768<p>All Global Variables and Functions have one of the following visibility
769 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]770
771<dl>
772 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]773 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]774 that the declaration is visible to other modules and, in shared libraries,
775 means that the declared entity may be overridden. On Darwin, default
776 visibility means that the declaration is visible to other modules. Default
777 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]778
779 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]780 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]781 object if they are in the same shared object. Usually, hidden visibility
782 indicates that the symbol will not be placed into the dynamic symbol
783 table, so no other module (executable or shared library) can reference it
784 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]785
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]786 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]787 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]788 the dynamic symbol table, but that references within the defining module
789 will bind to the local symbol. That is, the symbol cannot be overridden by
790 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]791</dl>
792
793</div>
794
795<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]796<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]797 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]798</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]799
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]800<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]801
802<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]803 it easier to read the IR and make the IR more condensed (particularly when
804 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]805
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]806<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]807%mytype = type { %mytype*, i32 }
808</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]809
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]810<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]811 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]812 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]813
814<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]815 and that you can therefore specify multiple names for the same type. This
816 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
817 uses structural typing, the name is not part of the type. When printing out
818 LLVM IR, the printer will pick <em>one name</em> to render all types of a
819 particular shape. This means that if you have code where two different
820 source types end up having the same LLVM type, that the dumper will sometimes
821 print the "wrong" or unexpected type. This is an important design point and
822 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]823
824</div>
825
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]826<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]827<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]828 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]829</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]830
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]831<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]832
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]833<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]834 instead of run-time. Global variables may optionally be initialized, may
835 have an explicit section to be placed in, and may have an optional explicit
836 alignment specified. A variable may be defined as "thread_local", which
837 means that it will not be shared by threads (each thread will have a
838 separated copy of the variable). A variable may be defined as a global
839 "constant," which indicates that the contents of the variable
840 will <b>never</b> be modified (enabling better optimization, allowing the
841 global data to be placed in the read-only section of an executable, etc).
842 Note that variables that need runtime initialization cannot be marked
843 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]844
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]845<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
846 constant, even if the final definition of the global is not. This capability
847 can be used to enable slightly better optimization of the program, but
848 requires the language definition to guarantee that optimizations based on the
849 'constantness' are valid for the translation units that do not include the
850 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]851
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]852<p>As SSA values, global variables define pointer values that are in scope
853 (i.e. they dominate) all basic blocks in the program. Global variables
854 always define a pointer to their "content" type because they describe a
855 region of memory, and all memory objects in LLVM are accessed through
856 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]857
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]858<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
859 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]860 like this can be merged with other constants if they have the same
861 initializer. Note that a constant with significant address <em>can</em>
862 be merged with a <tt>unnamed_addr</tt> constant, the result being a
863 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]864
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]865<p>A global variable may be declared to reside in a target-specific numbered
866 address space. For targets that support them, address spaces may affect how
867 optimizations are performed and/or what target instructions are used to
868 access the variable. The default address space is zero. The address space
869 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]870
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]871<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]872 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]873
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]874<p>An explicit alignment may be specified for a global, which must be a power
875 of 2. If not present, or if the alignment is set to zero, the alignment of
876 the global is set by the target to whatever it feels convenient. If an
877 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]878 alignment. Targets and optimizers are not allowed to over-align the global
879 if the global has an assigned section. In this case, the extra alignment
880 could be observable: for example, code could assume that the globals are
881 densely packed in their section and try to iterate over them as an array,
882 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]883
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]884<p>For example, the following defines a global in a numbered address space with
885 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]886
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]887<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]888@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]889</pre>
890
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]891</div>
892
893
894<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]895<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]896 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]897</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]898
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]899<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]900
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]901<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]902 optional <a href="#linkage">linkage type</a>, an optional
903 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]904 <a href="#callingconv">calling convention</a>,
905 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]906 <a href="#paramattrs">parameter attribute</a> for the return type, a function
907 name, a (possibly empty) argument list (each with optional
908 <a href="#paramattrs">parameter attributes</a>), optional
909 <a href="#fnattrs">function attributes</a>, an optional section, an optional
910 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
911 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]912
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]913<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
914 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]915 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]916 <a href="#callingconv">calling convention</a>,
917 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]918 <a href="#paramattrs">parameter attribute</a> for the return type, a function
919 name, a possibly empty list of arguments, an optional alignment, and an
920 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]921
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]922<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]923 (Control Flow Graph) for the function. Each basic block may optionally start
924 with a label (giving the basic block a symbol table entry), contains a list
925 of instructions, and ends with a <a href="#terminators">terminator</a>
926 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]927
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]928<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]929 executed on entrance to the function, and it is not allowed to have
930 predecessor basic blocks (i.e. there can not be any branches to the entry
931 block of a function). Because the block can have no predecessors, it also
932 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]933
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]934<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]935 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]936
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]937<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]938 the alignment is set to zero, the alignment of the function is set by the
939 target to whatever it feels convenient. If an explicit alignment is
940 specified, the function is forced to have at least that much alignment. All
941 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]942
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]943<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
944 be significant and two identical functions can be merged</p>.
945
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]946<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]947<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]948define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]949 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
950 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
951 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
952 [<a href="#gc">gc</a>] { ... }
953</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]954
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]955</div>
956
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]957<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]958<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]959 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]960</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]961
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]962<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]963
964<p>Aliases act as "second name" for the aliasee value (which can be either
965 function, global variable, another alias or bitcast of global value). Aliases
966 may have an optional <a href="#linkage">linkage type</a>, and an
967 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]968
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]969<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]970<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]971@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]972</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]973
974</div>
975
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]976<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]977<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]978 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]979</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]980
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]981<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]982
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]983<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]984 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]985 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]986
987<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]988<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]989; Some unnamed metadata nodes, which are referenced by the named metadata.
990!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]991!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]992!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]993; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]994!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]995</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]996
997</div>
998
999<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1000<h3>
1001 <a name="paramattrs">Parameter Attributes</a>
1002</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1003
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1004<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1005
1006<p>The return type and each parameter of a function type may have a set of
1007 <i>parameter attributes</i> associated with them. Parameter attributes are
1008 used to communicate additional information about the result or parameters of
1009 a function. Parameter attributes are considered to be part of the function,
1010 not of the function type, so functions with different parameter attributes
1011 can have the same function type.</p>
1012
1013<p>Parameter attributes are simple keywords that follow the type specified. If
1014 multiple parameter attributes are needed, they are space separated. For
1015 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1016
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1017<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1018declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1019declare i32 @atoi(i8 zeroext)
1020declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1021</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1022
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1023<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1024 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1025
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1026<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1027
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1028<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1029 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1030 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1031 should be zero-extended to the extent required by the target's ABI (which
1032 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1033 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1034
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1035 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1036 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1037 should be sign-extended to the extent required by the target's ABI (which
1038 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1039 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1040
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1041 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1042 <dd>This indicates that this parameter or return value should be treated in a
1043 special target-dependent fashion during while emitting code for a function
1044 call or return (usually, by putting it in a register as opposed to memory,
1045 though some targets use it to distinguish between two different kinds of
1046 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1047
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1048 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1049 <dd><p>This indicates that the pointer parameter should really be passed by
1050 value to the function. The attribute implies that a hidden copy of the
1051 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1052 is made between the caller and the callee, so the callee is unable to
1053 modify the value in the callee. This attribute is only valid on LLVM
1054 pointer arguments. It is generally used to pass structs and arrays by
1055 value, but is also valid on pointers to scalars. The copy is considered
1056 to belong to the caller not the callee (for example,
1057 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1058 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1059 values.</p>
1060
1061 <p>The byval attribute also supports specifying an alignment with
1062 the align attribute. It indicates the alignment of the stack slot to
1063 form and the known alignment of the pointer specified to the call site. If
1064 the alignment is not specified, then the code generator makes a
1065 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1066
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1067 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1068 <dd>This indicates that the pointer parameter specifies the address of a
1069 structure that is the return value of the function in the source program.
1070 This pointer must be guaranteed by the caller to be valid: loads and
1071 stores to the structure may be assumed by the callee to not to trap. This
1072 may only be applied to the first parameter. This is not a valid attribute
1073 for return values. </dd>
1074
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1075 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1076 <dd>This indicates that pointer values
1077 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1078 value do not alias pointer values which are not <i>based</i> on it,
1079 ignoring certain "irrelevant" dependencies.
1080 For a call to the parent function, dependencies between memory
1081 references from before or after the call and from those during the call
1082 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1083 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1084 The caller shares the responsibility with the callee for ensuring that
1085 these requirements are met.
1086 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1087 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1088<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1089 Note that this definition of <tt>noalias</tt> is intentionally
1090 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1091 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1092<br>
1093 For function return values, C99's <tt>restrict</tt> is not meaningful,
1094 while LLVM's <tt>noalias</tt> is.
1095 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1096
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1097 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1098 <dd>This indicates that the callee does not make any copies of the pointer
1099 that outlive the callee itself. This is not a valid attribute for return
1100 values.</dd>
1101
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1102 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1103 <dd>This indicates that the pointer parameter can be excised using the
1104 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1105 attribute for return values.</dd>
1106</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1107
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1108</div>
1109
1110<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1111<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1112 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1113</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1114
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1115<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1116
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1117<p>Each function may specify a garbage collector name, which is simply a
1118 string:</p>
1119
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1120<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1121define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1122</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1123
1124<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1125 collector which will cause the compiler to alter its output in order to
1126 support the named garbage collection algorithm.</p>
1127
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1128</div>
1129
1130<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1131<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1132 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1133</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1134
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1135<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1137<p>Function attributes are set to communicate additional information about a
1138 function. Function attributes are considered to be part of the function, not
1139 of the function type, so functions with different parameter attributes can
1140 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1141
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1142<p>Function attributes are simple keywords that follow the type specified. If
1143 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1144
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1145<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1146define void @f() noinline { ... }
1147define void @f() alwaysinline { ... }
1148define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1149define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1150</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1151
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1152<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1153 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1154 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1155 the backend should forcibly align the stack pointer. Specify the
1156 desired alignment, which must be a power of two, in parentheses.
1157
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1158 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1159 <dd>This attribute indicates that the inliner should attempt to inline this
1160 function into callers whenever possible, ignoring any active inlining size
1161 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1162
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1163 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1164 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1165 meaning the function can be patched and/or hooked even while it is
1166 loaded into memory. On x86, the function prologue will be preceded
1167 by six bytes of padding and will begin with a two-byte instruction.
1168 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1169 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1170
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1171 <dt><tt><b>nonlazybind</b></tt></dt>
1172 <dd>This attribute suppresses lazy symbol binding for the function. This
1173 may make calls to the function faster, at the cost of extra program
1174 startup time if the function is not called during program startup.</dd>
1175
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1176 <dt><tt><b>inlinehint</b></tt></dt>
1177 <dd>This attribute indicates that the source code contained a hint that inlining
1178 this function is desirable (such as the "inline" keyword in C/C++). It
1179 is just a hint; it imposes no requirements on the inliner.</dd>
1180
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1181 <dt><tt><b>naked</b></tt></dt>
1182 <dd>This attribute disables prologue / epilogue emission for the function.
1183 This can have very system-specific consequences.</dd>
1184
1185 <dt><tt><b>noimplicitfloat</b></tt></dt>
1186 <dd>This attributes disables implicit floating point instructions.</dd>
1187
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1188 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1189 <dd>This attribute indicates that the inliner should never inline this
1190 function in any situation. This attribute may not be used together with
1191 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1192
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1193 <dt><tt><b>noredzone</b></tt></dt>
1194 <dd>This attribute indicates that the code generator should not use a red
1195 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1196
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1197 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1198 <dd>This function attribute indicates that the function never returns
1199 normally. This produces undefined behavior at runtime if the function
1200 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1201
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1202 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1203 <dd>This function attribute indicates that the function never returns with an
1204 unwind or exceptional control flow. If the function does unwind, its
1205 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1206
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1207 <dt><tt><b>optsize</b></tt></dt>
1208 <dd>This attribute suggests that optimization passes and code generator passes
1209 make choices that keep the code size of this function low, and otherwise
1210 do optimizations specifically to reduce code size.</dd>
1211
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1212 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1213 <dd>This attribute indicates that the function computes its result (or decides
1214 to unwind an exception) based strictly on its arguments, without
1215 dereferencing any pointer arguments or otherwise accessing any mutable
1216 state (e.g. memory, control registers, etc) visible to caller functions.
1217 It does not write through any pointer arguments
1218 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1219 changes any state visible to callers. This means that it cannot unwind
1220 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1221 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1222
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1223 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1224 <dd>This attribute indicates that the function does not write through any
1225 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1226 arguments) or otherwise modify any state (e.g. memory, control registers,
1227 etc) visible to caller functions. It may dereference pointer arguments
1228 and read state that may be set in the caller. A readonly function always
1229 returns the same value (or unwinds an exception identically) when called
1230 with the same set of arguments and global state. It cannot unwind an
1231 exception by calling the <tt>C++</tt> exception throwing methods, but may
1232 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1233
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1234 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1235 <dd>This attribute indicates that the function should emit a stack smashing
1236 protector. It is in the form of a "canary"&mdash;a random value placed on
1237 the stack before the local variables that's checked upon return from the
1238 function to see if it has been overwritten. A heuristic is used to
1239 determine if a function needs stack protectors or not.<br>
1240<br>
1241 If a function that has an <tt>ssp</tt> attribute is inlined into a
1242 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1243 function will have an <tt>ssp</tt> attribute.</dd>
1244
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1245 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1246 <dd>This attribute indicates that the function should <em>always</em> emit a
1247 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1248 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1249<br>
1250 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1251 function that doesn't have an <tt>sspreq</tt> attribute or which has
1252 an <tt>ssp</tt> attribute, then the resulting function will have
1253 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindola163d6752011-07-25 15:27:59 +0000[diff] [blame]1254
1255 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1256 <dd>This attribute indicates that the ABI being targeted requires that
1257 an unwind table entry be produce for this function even if we can
1258 show that no exceptions passes by it. This is normally the case for
1259 the ELF x86-64 abi, but it can be disabled for some compilation
1260 units.</dd>
1261
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1262</dl>
1263
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1264</div>
1265
1266<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1267<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1268 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1269</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1271<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1272
1273<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1274 the GCC "file scope inline asm" blocks. These blocks are internally
1275 concatenated by LLVM and treated as a single unit, but may be separated in
1276 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1277
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1278<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1279module asm "inline asm code goes here"
1280module asm "more can go here"
1281</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1282
1283<p>The strings can contain any character by escaping non-printable characters.
1284 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]1285 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1286
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1287<p>The inline asm code is simply printed to the machine code .s file when
1288 assembly code is generated.</p>
1289
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1290</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1291
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1292<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1293<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1294 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1295</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1296
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1297<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1298
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1299<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1300 data is to be laid out in memory. The syntax for the data layout is
1301 simply:</p>
1302
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1303<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1304target datalayout = "<i>layout specification</i>"
1305</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1306
1307<p>The <i>layout specification</i> consists of a list of specifications
1308 separated by the minus sign character ('-'). Each specification starts with
1309 a letter and may include other information after the letter to define some
1310 aspect of the data layout. The specifications accepted are as follows:</p>
1311
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1312<dl>
1313 <dt><tt>E</tt></dt>
1314 <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]1315 bits with the most significance have the lowest address location.</dd>
1316
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1317 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1318 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1319 the bits with the least significance have the lowest address
1320 location.</dd>
1321
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1322 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1323 <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]1324 <i>preferred</i> alignments. All sizes are in bits. Specifying
1325 the <i>pref</i> alignment is optional. If omitted, the
1326 preceding <tt>:</tt> should be omitted too.</dd>
1327
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1328 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1329 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1330 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1331
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1332 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1333 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1334 <i>size</i>.</dd>
1335
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1336 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1337 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1338 <i>size</i>. Only values of <i>size</i> that are supported by the target
1339 will work. 32 (float) and 64 (double) are supported on all targets;
1340 80 or 128 (different flavors of long double) are also supported on some
1341 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1342
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1343 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1344 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1345 <i>size</i>.</dd>
1346
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1347 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1348 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1349 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1350
1351 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1352 <dd>This specifies a set of native integer widths for the target CPU
1353 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1354 "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]1355 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1356 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1357</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1358
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1359<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1360 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1361 specifications in the <tt>datalayout</tt> keyword. The default specifications
1362 are given in this list:</p>
1363
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1364<ul>
1365 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1366 <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]1367 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1368 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1369 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1370 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1371 <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]1372 alignment of 64-bits</li>
1373 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1374 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1375 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1376 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1377 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1378 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1379</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1380
1381<p>When LLVM is determining the alignment for a given type, it uses the
1382 following rules:</p>
1383
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1384<ol>
1385 <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]1386 specification is used.</li>
1387
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1388 <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]1389 smallest integer type that is larger than the bitwidth of the sought type
1390 is used. If none of the specifications are larger than the bitwidth then
1391 the the largest integer type is used. For example, given the default
1392 specifications above, the i7 type will use the alignment of i8 (next
1393 largest) while both i65 and i256 will use the alignment of i64 (largest
1394 specified).</li>
1395
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1396 <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]1397 largest vector type that is smaller than the sought vector type will be
1398 used as a fall back. This happens because &lt;128 x double&gt; can be
1399 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1400</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1401
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1402</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1403
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1404<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1405<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1406 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1407</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1408
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1409<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1410
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1411<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1412with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1413is undefined. Pointer values are associated with address ranges
1414according to the following rules:</p>
1415
1416<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1417 <li>A pointer value is associated with the addresses associated with
1418 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1419 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1420 range of the variable's storage.</li>
1421 <li>The result value of an allocation instruction is associated with
1422 the address range of the allocated storage.</li>
1423 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1424 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1425 <li>An integer constant other than zero or a pointer value returned
1426 from a function not defined within LLVM may be associated with address
1427 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1428 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1429 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1430</ul>
1431
1432<p>A pointer value is <i>based</i> on another pointer value according
1433 to the following rules:</p>
1434
1435<ul>
1436 <li>A pointer value formed from a
1437 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1438 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1439 <li>The result value of a
1440 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1441 of the <tt>bitcast</tt>.</li>
1442 <li>A pointer value formed by an
1443 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1444 pointer values that contribute (directly or indirectly) to the
1445 computation of the pointer's value.</li>
1446 <li>The "<i>based</i> on" relationship is transitive.</li>
1447</ul>
1448
1449<p>Note that this definition of <i>"based"</i> is intentionally
1450 similar to the definition of <i>"based"</i> in C99, though it is
1451 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1452
1453<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1454<tt><a href="#i_load">load</a></tt> merely indicates the size and
1455alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1456interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1457<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1458and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1459
1460<p>Consequently, type-based alias analysis, aka TBAA, aka
1461<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1462LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1463additional information which specialized optimization passes may use
1464to implement type-based alias analysis.</p>
1465
1466</div>
1467
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1468<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1469<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1470 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1471</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1472
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1473<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1474
1475<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1476href="#i_store"><tt>store</tt></a>s, and <a
1477href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1478The optimizers must not change the number of volatile operations or change their
1479order of execution relative to other volatile operations. The optimizers
1480<i>may</i> change the order of volatile operations relative to non-volatile
1481operations. This is not Java's "volatile" and has no cross-thread
1482synchronization behavior.</p>
1483
1484</div>
1485
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1486<!-- ======================================================================= -->
1487<h3>
1488 <a name="memmodel">Memory Model for Concurrent Operations</a>
1489</h3>
1490
1491<div>
1492
1493<p>The LLVM IR does not define any way to start parallel threads of execution
1494or to register signal handlers. Nonetheless, there are platform-specific
1495ways to create them, and we define LLVM IR's behavior in their presence. This
1496model is inspired by the C++0x memory model.</p>
1497
1498<p>We define a <i>happens-before</i> partial order as the least partial order
1499that</p>
1500<ul>
1501 <li>Is a superset of single-thread program order, and</li>
1502 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1503 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1504 by platform-specific techniques, like pthread locks, thread
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1505 creation, thread joining, etc., and by atomic instructions.
1506 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1507 </li>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1508</ul>
1509
1510<p>Note that program order does not introduce <i>happens-before</i> edges
1511between a thread and signals executing inside that thread.</p>
1512
1513<p>Every (defined) read operation (load instructions, memcpy, atomic
1514loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1515(defined) write operations (store instructions, atomic
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1516stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1517initialized globals are considered to have a write of the initializer which is
1518atomic and happens before any other read or write of the memory in question.
1519For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1520any write to the same byte, except:</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1521
1522<ul>
1523 <li>If <var>write<sub>1</sub></var> happens before
1524 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1525 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1526 does not see <var>write<sub>1</sub></var>.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1527 <li>If <var>R<sub>byte</sub></var> happens before <var>write<sub>3</var>,
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1528 then <var>R<sub>byte</sub></var> does not see
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1529 <var>write<sub>3</sub></var>.
1530</ul>
1531
1532<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1533<ul>
1534 <li>If there is no write to the same byte that happens before
1535 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1536 <tt>undef</tt> for that byte.
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1537 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1538 <var>R<sub>byte</sub></var> returns the value written by that
1539 write.</li>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1540 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1541 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1542 values written. See the <a href="#ordering">Atomic Memory Ordering
1543 Constraints</a> section for additional constraints on how the choice
1544 is made.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1545 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1546</ul>
1547
1548<p><var>R</var> returns the value composed of the series of bytes it read.
1549This implies that some bytes within the value may be <tt>undef</tt>
1550<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1551defines the semantics of the operation; it doesn't mean that targets will
1552emit more than one instruction to read the series of bytes.</p>
1553
1554<p>Note that in cases where none of the atomic intrinsics are used, this model
1555places only one restriction on IR transformations on top of what is required
1556for single-threaded execution: introducing a store to a byte which might not
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1557otherwise be stored to can introduce undefined behavior. (Specifically, in
1558the case where another thread might write to and read from an address,
1559introducing a store can change a load that may see exactly one write into
1560a load that may see multiple writes.)</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1561
1562<!-- FIXME: This model assumes all targets where concurrency is relevant have
1563a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1564none of the backends currently in the tree fall into this category; however,
1565there might be targets which care. If there are, we want a paragraph
1566like the following:
1567
1568Targets may specify that stores narrower than a certain width are not
1569available; on such a target, for the purposes of this model, treat any
1570non-atomic write with an alignment or width less than the minimum width
1571as if it writes to the relevant surrounding bytes.
1572-->
1573
1574</div>
1575
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1576<!-- ======================================================================= -->
1577<div class="doc_subsection">
1578 <a name="ordering">Atomic Memory Ordering Constraints</a>
1579</div>
1580
1581<div class="doc_text">
1582
1583<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
1584<a href="#i_atomicrmw"><code>atomicrmw</code></a>, and
1585<a href="#i_fence"><code>fence</code></a>) take an ordering parameter
1586that determines which other atomic instructions on the same address they
1587<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1588but are somewhat more colloquial. If these descriptions aren't precise enough,
1589check those specs. <a href="#i_fence"><code>fence</code></a> instructions
1590treat these orderings somewhat differently since they don't take an address.
1591See that instruction's documentation for details.</p>
1592
1593<!-- FIXME Note atomic load+store here once those get added. -->
1594
1595<dl>
1596<!-- FIXME: unordered is intended to be used for atomic load and store;
1597it isn't allowed for any instruction yet. -->
1598<dt><code>unordered</code></dt>
1599<dd>The set of values that can be read is governed by the happens-before
1600partial order. A value cannot be read unless some operation wrote it.
1601This is intended to provide a guarantee strong enough to model Java's
1602non-volatile shared variables. This ordering cannot be specified for
1603read-modify-write operations; it is not strong enough to make them atomic
1604in any interesting way.</dd>
1605<dt><code>monotonic</code></dt>
1606<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1607total order for modifications by <code>monotonic</code> operations on each
1608address. All modification orders must be compatible with the happens-before
1609order. There is no guarantee that the modification orders can be combined to
1610a global total order for the whole program (and this often will not be
1611possible). The read in an atomic read-modify-write operation
1612(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1613<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1614reads the value in the modification order immediately before the value it
1615writes. If one atomic read happens before another atomic read of the same
1616address, the later read must see the same value or a later value in the
1617address's modification order. This disallows reordering of
1618<code>monotonic</code> (or stronger) operations on the same address. If an
1619address is written <code>monotonic</code>ally by one thread, and other threads
1620<code>monotonic</code>ally read that address repeatedly, the other threads must
1621eventually see the write. This is intended to model C++'s relaxed atomic
1622variables.</dd>
1623<dt><code>acquire</code></dt>
1624<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1625reads a value written by a <code>release</code> atomic operation, it
1626<i>synchronizes-with</i> that operation.</dd>
1627<dt><code>release</code></dt>
1628<dd>In addition to the guarantees of <code>monotonic</code>,
1629a <i>synchronizes-with</i> edge may be formed by an <code>acquire</code>
1630operation.</dd>
1631<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
1632<code>acquire</code> and <code>release</code> operation on its address.</dd>
1633<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1634<dd>In addition to the guarantees of <code>acq_rel</code>
1635(<code>acquire</code> for an operation which only reads, <code>release</code>
1636for an operation which only writes), there is a global total order on all
1637sequentially-consistent operations on all addresses, which is consistent with
1638the <i>happens-before</i> partial order and with the modification orders of
1639all the affected addresses. Each sequentially-consistent read sees the last
1640preceding write to the same address in this global order. This is intended
1641to model C++'s sequentially-consistent atomic variables and Java's volatile
1642shared variables.</dd>
1643</dl>
1644
1645<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1646it only <i>synchronizes with</i> or participates in modification and seq_cst
1647total orderings with other operations running in the same thread (for example,
1648in signal handlers).</p>
1649
1650</div>
1651
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1652</div>
1653
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1654<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1655<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1656<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1657
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1658<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1659
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1660<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1661 intermediate representation. Being typed enables a number of optimizations
1662 to be performed on the intermediate representation directly, without having
1663 to do extra analyses on the side before the transformation. A strong type
1664 system makes it easier to read the generated code and enables novel analyses
1665 and transformations that are not feasible to perform on normal three address
1666 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1667
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1668<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1669<h3>
1670 <a name="t_classifications">Type Classifications</a>
1671</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1672
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1673<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1674
1675<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1676
1677<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1678 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1679 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1680 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1681 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1682 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1683 </tr>
1684 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1685 <td><a href="#t_floating">floating point</a></td>
1686 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1687 </tr>
1688 <tr>
1689 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1690 <td><a href="#t_integer">integer</a>,
1691 <a href="#t_floating">floating point</a>,
1692 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1693 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1694 <a href="#t_struct">structure</a>,
1695 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1696 <a href="#t_label">label</a>,
1697 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1698 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1699 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1700 <tr>
1701 <td><a href="#t_primitive">primitive</a></td>
1702 <td><a href="#t_label">label</a>,
1703 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1704 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1705 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1706 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1707 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1708 </tr>
1709 <tr>
1710 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1711 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1712 <a href="#t_function">function</a>,
1713 <a href="#t_pointer">pointer</a>,
1714 <a href="#t_struct">structure</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1715 <a href="#t_vector">vector</a>,
1716 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1717 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1718 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1719 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1720</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1721
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1722<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1723 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1724 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1725
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1726</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1727
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1728<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1729<h3>
1730 <a name="t_primitive">Primitive Types</a>
1731</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1732
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1733<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1734
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1735<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1736 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1737
1738<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1739<h4>
1740 <a name="t_integer">Integer Type</a>
1741</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1742
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1743<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1744
1745<h5>Overview:</h5>
1746<p>The integer type is a very simple type that simply specifies an arbitrary
1747 bit width for the integer type desired. Any bit width from 1 bit to
1748 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1749
1750<h5>Syntax:</h5>
1751<pre>
1752 iN
1753</pre>
1754
1755<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1756 value.</p>
1757
1758<h5>Examples:</h5>
1759<table class="layout">
1760 <tr class="layout">
1761 <td class="left"><tt>i1</tt></td>
1762 <td class="left">a single-bit integer.</td>
1763 </tr>
1764 <tr class="layout">
1765 <td class="left"><tt>i32</tt></td>
1766 <td class="left">a 32-bit integer.</td>
1767 </tr>
1768 <tr class="layout">
1769 <td class="left"><tt>i1942652</tt></td>
1770 <td class="left">a really big integer of over 1 million bits.</td>
1771 </tr>
1772</table>
1773
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1774</div>
1775
1776<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1777<h4>
1778 <a name="t_floating">Floating Point Types</a>
1779</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1780
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1781<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1782
1783<table>
1784 <tbody>
1785 <tr><th>Type</th><th>Description</th></tr>
1786 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1787 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1788 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1789 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1790 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1791 </tbody>
1792</table>
1793
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1794</div>
1795
1796<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1797<h4>
1798 <a name="t_x86mmx">X86mmx Type</a>
1799</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1800
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1801<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1802
1803<h5>Overview:</h5>
1804<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>
1805
1806<h5>Syntax:</h5>
1807<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1808 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1809</pre>
1810
1811</div>
1812
1813<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1814<h4>
1815 <a name="t_void">Void Type</a>
1816</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1817
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1818<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1819
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1820<h5>Overview:</h5>
1821<p>The void type does not represent any value and has no size.</p>
1822
1823<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1824<pre>
1825 void
1826</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1827
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1828</div>
1829
1830<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1831<h4>
1832 <a name="t_label">Label Type</a>
1833</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1834
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1835<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1836
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1837<h5>Overview:</h5>
1838<p>The label type represents code labels.</p>
1839
1840<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1841<pre>
1842 label
1843</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1844
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1845</div>
1846
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1847<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1848<h4>
1849 <a name="t_metadata">Metadata Type</a>
1850</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1851
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1852<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1853
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1854<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1855<p>The metadata type represents embedded metadata. No derived types may be
1856 created from metadata except for <a href="#t_function">function</a>
1857 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1858
1859<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1860<pre>
1861 metadata
1862</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1863
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1864</div>
1865
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1866</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1867
1868<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1869<h3>
1870 <a name="t_derived">Derived Types</a>
1871</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1872
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1873<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1874
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1875<p>The real power in LLVM comes from the derived types in the system. This is
1876 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1877 useful types. Each of these types contain one or more element types which
1878 may be a primitive type, or another derived type. For example, it is
1879 possible to have a two dimensional array, using an array as the element type
1880 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1881
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1882</div>
1883
1884
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1885<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1886<h4>
1887 <a name="t_aggregate">Aggregate Types</a>
1888</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1889
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1890<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1891
1892<p>Aggregate Types are a subset of derived types that can contain multiple
1893 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1894 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1895 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1896
1897</div>
1898
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1899<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1900<h4>
1901 <a name="t_array">Array Type</a>
1902</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1903
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1904<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1905
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1906<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1907<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1908 sequentially in memory. The array type requires a size (number of elements)
1909 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1910
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1911<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1912<pre>
1913 [&lt;# elements&gt; x &lt;elementtype&gt;]
1914</pre>
1915
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1916<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1917 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1918
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1919<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1920<table class="layout">
1921 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1922 <td class="left"><tt>[40 x i32]</tt></td>
1923 <td class="left">Array of 40 32-bit integer values.</td>
1924 </tr>
1925 <tr class="layout">
1926 <td class="left"><tt>[41 x i32]</tt></td>
1927 <td class="left">Array of 41 32-bit integer values.</td>
1928 </tr>
1929 <tr class="layout">
1930 <td class="left"><tt>[4 x i8]</tt></td>
1931 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1932 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1933</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1934<p>Here are some examples of multidimensional arrays:</p>
1935<table class="layout">
1936 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1937 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1938 <td class="left">3x4 array of 32-bit integer values.</td>
1939 </tr>
1940 <tr class="layout">
1941 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1942 <td class="left">12x10 array of single precision floating point values.</td>
1943 </tr>
1944 <tr class="layout">
1945 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1946 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1947 </tr>
1948</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1949
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1950<p>There is no restriction on indexing beyond the end of the array implied by
1951 a static type (though there are restrictions on indexing beyond the bounds
1952 of an allocated object in some cases). This means that single-dimension
1953 'variable sized array' addressing can be implemented in LLVM with a zero
1954 length array type. An implementation of 'pascal style arrays' in LLVM could
1955 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1956
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1957</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1958
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1959<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1960<h4>
1961 <a name="t_function">Function Type</a>
1962</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1963
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1964<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1965
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1966<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1967<p>The function type can be thought of as a function signature. It consists of
1968 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]1969 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1970
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1971<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1972<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1973 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1974</pre>
1975
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1976<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]1977 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1978 which indicates that the function takes a variable number of arguments.
1979 Variable argument functions can access their arguments with
1980 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1981 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1982 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1983
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1984<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1985<table class="layout">
1986 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1987 <td class="left"><tt>i32 (i32)</tt></td>
1988 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1989 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1990 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1991 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1992 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1993 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1994 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1995 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1996 </td>
1997 </tr><tr class="layout">
1998 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1999 <td class="left">A vararg function that takes at least one
2000 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2001 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]2002 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2003 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2004 </tr><tr class="layout">
2005 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]2006 <td class="left">A function taking an <tt>i32</tt>, returning a
2007 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2008 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2009 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2010</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2011
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2012</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2013
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2014<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2015<h4>
2016 <a name="t_struct">Structure Type</a>
2017</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2018
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2019<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2020
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2022<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2023 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]2024
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]2025<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2026 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2027 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2028 Structures in registers are accessed using the
2029 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2030 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2031
2032<p>Structures may optionally be "packed" structures, which indicate that the
2033 alignment of the struct is one byte, and that there is no padding between
2034 the elements. In non-packed structs, padding between field types is defined
2035 by the target data string to match the underlying processor.</p>
2036
2037<p>Structures can either be "anonymous" or "named". An anonymous structure is
2038 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
2039 are always defined at the top level with a name. Anonmyous types are uniqued
2040 by their contents and can never be recursive since there is no way to write
2041 one. Named types can be recursive.
2042</p>
2043
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2044<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2045<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2046 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
2047 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2048</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2049
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2050<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2051<table class="layout">
2052 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2053 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2054 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2055 </tr>
2056 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2057 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2058 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2059 second element is a <a href="#t_pointer">pointer</a> to a
2060 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2061 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2062 </tr>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2063 <tr class="layout">
2064 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2065 <td class="left">A packed struct known to be 5 bytes in size.</td>
2066 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2067</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2068
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2069</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2070
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2071<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2072<h4>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2073 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2074</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2075
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2076<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2077
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2078<h5>Overview:</h5>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2079<p>Opaque structure types are used to represent named structure types that do
2080 not have a body specified. This corresponds (for example) to the C notion of
2081 a forward declared structure.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2082
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2083<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2084<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2085 %X = type opaque
2086 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2087</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2088
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2089<h5>Examples:</h5>
2090<table class="layout">
2091 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2092 <td class="left"><tt>opaque</tt></td>
2093 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2094 </tr>
2095</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2096
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2097</div>
2098
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2099
2100
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2101<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2102<h4>
2103 <a name="t_pointer">Pointer Type</a>
2104</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2105
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2106<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2107
2108<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]2109<p>The pointer type is used to specify memory locations.
2110 Pointers are commonly used to reference objects in memory.</p>
2111
2112<p>Pointer types may have an optional address space attribute defining the
2113 numbered address space where the pointed-to object resides. The default
2114 address space is number zero. The semantics of non-zero address
2115 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2116
2117<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2118 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2119
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2120<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2121<pre>
2122 &lt;type&gt; *
2123</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2124
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2125<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2126<table class="layout">
2127 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2128 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2129 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2130 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2131 </tr>
2132 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]2133 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2134 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2135 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2136 <tt>i32</tt>.</td>
2137 </tr>
2138 <tr class="layout">
2139 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2140 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2141 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2142 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2143</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2144
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2145</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2146
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2147<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2148<h4>
2149 <a name="t_vector">Vector Type</a>
2150</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2151
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2152<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2153
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2154<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2155<p>A vector type is a simple derived type that represents a vector of elements.
2156 Vector types are used when multiple primitive data are operated in parallel
2157 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]2158 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2159 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2160
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2161<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2162<pre>
2163 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2164</pre>
2165
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]2166<p>The number of elements is a constant integer value larger than 0; elementtype
2167 may be any integer or floating point type. Vectors of size zero are not
2168 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2169
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2170<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2171<table class="layout">
2172 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2173 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2174 <td class="left">Vector of 4 32-bit integer values.</td>
2175 </tr>
2176 <tr class="layout">
2177 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2178 <td class="left">Vector of 8 32-bit floating-point values.</td>
2179 </tr>
2180 <tr class="layout">
2181 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2182 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2183 </tr>
2184</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2185
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2186</div>
2187
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2188<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2189<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2190<!-- *********************************************************************** -->
2191
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2192<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2193
2194<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2195 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2196
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2197<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2198<h3>
2199 <a name="simpleconstants">Simple Constants</a>
2200</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2201
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2202<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2203
2204<dl>
2205 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2206 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2207 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2208
2209 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2210 <dd>Standard integers (such as '4') are constants of
2211 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2212 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2213
2214 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2215 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2216 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2217 notation (see below). The assembler requires the exact decimal value of a
2218 floating-point constant. For example, the assembler accepts 1.25 but
2219 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2220 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2221
2222 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2223 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2224 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2225</dl>
2226
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2227<p>The one non-intuitive notation for constants is the hexadecimal form of
2228 floating point constants. For example, the form '<tt>double
2229 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2230 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2231 constants are required (and the only time that they are generated by the
2232 disassembler) is when a floating point constant must be emitted but it cannot
2233 be represented as a decimal floating point number in a reasonable number of
2234 digits. For example, NaN's, infinities, and other special values are
2235 represented in their IEEE hexadecimal format so that assembly and disassembly
2236 do not cause any bits to change in the constants.</p>
2237
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2238<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2239 represented using the 16-digit form shown above (which matches the IEEE754
2240 representation for double); float values must, however, be exactly
2241 representable as IEE754 single precision. Hexadecimal format is always used
2242 for long double, and there are three forms of long double. The 80-bit format
2243 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2244 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2245 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2246 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2247 currently supported target uses this format. Long doubles will only work if
2248 they match the long double format on your target. All hexadecimal formats
2249 are big-endian (sign bit at the left).</p>
2250
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2251<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2252</div>
2253
2254<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2255<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2256<a name="aggregateconstants"></a> <!-- old anchor -->
2257<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2258</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2259
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2260<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2261
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2262<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2263 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2264
2265<dl>
2266 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2267 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2268 type definitions (a comma separated list of elements, surrounded by braces
2269 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2270 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2271 Structure constants must have <a href="#t_struct">structure type</a>, and
2272 the number and types of elements must match those specified by the
2273 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2274
2275 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2276 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2277 definitions (a comma separated list of elements, surrounded by square
2278 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2279 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2280 the number and types of elements must match those specified by the
2281 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2282
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2283 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2284 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2285 definitions (a comma separated list of elements, surrounded by
2286 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2287 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2288 have <a href="#t_vector">vector type</a>, and the number and types of
2289 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2290
2291 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2292 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2293 value to zero of <em>any</em> type, including scalar and
2294 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2295 This is often used to avoid having to print large zero initializers
2296 (e.g. for large arrays) and is always exactly equivalent to using explicit
2297 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2298
2299 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2300 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2301 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2302 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2303 be interpreted as part of the instruction stream, metadata is a place to
2304 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2305</dl>
2306
2307</div>
2308
2309<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2310<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2311 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2312</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2313
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2314<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2315
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2316<p>The addresses of <a href="#globalvars">global variables</a>
2317 and <a href="#functionstructure">functions</a> are always implicitly valid
2318 (link-time) constants. These constants are explicitly referenced when
2319 the <a href="#identifiers">identifier for the global</a> is used and always
2320 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2321 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2322
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2323<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2324@X = global i32 17
2325@Y = global i32 42
2326@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2327</pre>
2328
2329</div>
2330
2331<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2332<h3>
2333 <a name="undefvalues">Undefined Values</a>
2334</h3>
2335
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2336<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2337
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2338<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]2339 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2340 Undefined values may be of any type (other than '<tt>label</tt>'
2341 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2342
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2343<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2344 program is well defined no matter what value is used. This gives the
2345 compiler more freedom to optimize. Here are some examples of (potentially
2346 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2347
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2348
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2349<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2350 %A = add %X, undef
2351 %B = sub %X, undef
2352 %C = xor %X, undef
2353Safe:
2354 %A = undef
2355 %B = undef
2356 %C = undef
2357</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2358
2359<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]2360 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]2361
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2362<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2363 %A = or %X, undef
2364 %B = and %X, undef
2365Safe:
2366 %A = -1
2367 %B = 0
2368Unsafe:
2369 %A = undef
2370 %B = undef
2371</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2372
2373<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2374 For example, if <tt>%X</tt> has a zero bit, then the output of the
2375 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2376 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2377 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2378 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2379 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2380 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2381 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2382
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2383<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2384 %A = select undef, %X, %Y
2385 %B = select undef, 42, %Y
2386 %C = select %X, %Y, undef
2387Safe:
2388 %A = %X (or %Y)
2389 %B = 42 (or %Y)
2390 %C = %Y
2391Unsafe:
2392 %A = undef
2393 %B = undef
2394 %C = undef
2395</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2396
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2397<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2398 branch) conditions can go <em>either way</em>, but they have to come from one
2399 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2400 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2401 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2402 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2403 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2404 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2405
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2406<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2407 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2408
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2409 %B = undef
2410 %C = xor %B, %B
2411
2412 %D = undef
2413 %E = icmp lt %D, 4
2414 %F = icmp gte %D, 4
2415
2416Safe:
2417 %A = undef
2418 %B = undef
2419 %C = undef
2420 %D = undef
2421 %E = undef
2422 %F = undef
2423</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2424
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2425<p>This example points out that two '<tt>undef</tt>' operands are not
2426 necessarily the same. This can be surprising to people (and also matches C
2427 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2428 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2429 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2430 its value over its "live range". This is true because the variable doesn't
2431 actually <em>have a live range</em>. Instead, the value is logically read
2432 from arbitrary registers that happen to be around when needed, so the value
2433 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2434 need to have the same semantics or the core LLVM "replace all uses with"
2435 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2436
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2437<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2438 %A = fdiv undef, %X
2439 %B = fdiv %X, undef
2440Safe:
2441 %A = undef
2442b: unreachable
2443</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2444
2445<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2446 value</em> and <em>undefined behavior</em>. An undefined value (like
2447 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2448 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2449 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2450 defined on SNaN's. However, in the second example, we can make a more
2451 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2452 arbitrary value, we are allowed to assume that it could be zero. Since a
2453 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2454 the operation does not execute at all. This allows us to delete the divide and
2455 all code after it. Because the undefined operation "can't happen", the
2456 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2457
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2458<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2459a: store undef -> %X
2460b: store %X -> undef
2461Safe:
2462a: &lt;deleted&gt;
2463b: unreachable
2464</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2465
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2466<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2467 undefined value can be assumed to not have any effect; we can assume that the
2468 value is overwritten with bits that happen to match what was already there.
2469 However, a store <em>to</em> an undefined location could clobber arbitrary
2470 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2471
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2472</div>
2473
2474<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2475<h3>
2476 <a name="trapvalues">Trap Values</a>
2477</h3>
2478
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2479<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2480
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2481<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2482 instead of representing an unspecified bit pattern, they represent the
2483 fact that an instruction or constant expression which cannot evoke side
2484 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2485 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2486
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2487<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]2488 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2489 <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]2490
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2491<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2492
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2493<ul>
2494<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2495 their operands.</li>
2496
2497<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2498 to their dynamic predecessor basic block.</li>
2499
2500<li>Function arguments depend on the corresponding actual argument values in
2501 the dynamic callers of their functions.</li>
2502
2503<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2504 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2505 control back to them.</li>
2506
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2507<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2508 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2509 or exception-throwing call instructions that dynamically transfer control
2510 back to them.</li>
2511
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2512<li>Non-volatile loads and stores depend on the most recent stores to all of the
2513 referenced memory addresses, following the order in the IR
2514 (including loads and stores implied by intrinsics such as
2515 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2516
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2517<!-- TODO: In the case of multiple threads, this only applies if the store
2518 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2519
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2520<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2521
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2522<li>An instruction with externally visible side effects depends on the most
2523 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2524 the order in the IR. (This includes
2525 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2526
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2527<li>An instruction <i>control-depends</i> on a
2528 <a href="#terminators">terminator instruction</a>
2529 if the terminator instruction has multiple successors and the instruction
2530 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2531 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2532
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2533<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2534 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2535 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2536 successor.</li>
2537
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2538<li>Dependence is transitive.</li>
2539
2540</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2541
2542<p>Whenever a trap value is generated, all values which depend on it evaluate
2543 to trap. If they have side effects, the evoke their side effects as if each
2544 operand with a trap value were undef. If they have externally-visible side
2545 effects, the behavior is undefined.</p>
2546
2547<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2548
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2549<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2550entry:
2551 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2552 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2553 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2554 store i32 0, i32* %trap_yet_again ; undefined behavior
2555
2556 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2557 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2558
2559 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2560
2561 %narrowaddr = bitcast i32* @g to i16*
2562 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2563 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2564 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2565
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2566 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2567 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2568
2569true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2570 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2571 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2572 br label %end
2573
2574end:
2575 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2576 ; Both edges into this PHI are
2577 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2578 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2579
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2580 volatile store i32 0, i32* @g ; This would depend on the store in %true
2581 ; if %cmp is true, or the store in %entry
2582 ; otherwise, so this is undefined behavior.
2583
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2584 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2585 ; The same branch again, but this time the
2586 ; true block doesn't have side effects.
2587
2588second_true:
2589 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2590 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2591
2592second_end:
2593 volatile store i32 0, i32* @g ; This time, the instruction always depends
2594 ; on the store in %end. Also, it is
2595 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2596 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2597 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2598</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2599
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2600</div>
2601
2602<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2603<h3>
2604 <a name="blockaddress">Addresses of Basic Blocks</a>
2605</h3>
2606
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2607<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2608
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2609<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2610
2611<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2612 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2613 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2614
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2615<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2616 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2617 comparisons against null. Pointer equality tests between labels addresses
2618 results in undefined behavior &mdash; though, again, comparison against null
2619 is ok, and no label is equal to the null pointer. This may be passed around
2620 as an opaque pointer sized value as long as the bits are not inspected. This
2621 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2622 long as the original value is reconstituted before the <tt>indirectbr</tt>
2623 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2624
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2625<p>Finally, some targets may provide defined semantics when using the value as
2626 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2627
2628</div>
2629
2630
2631<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2632<h3>
2633 <a name="constantexprs">Constant Expressions</a>
2634</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2635
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2636<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2637
2638<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2639 to be used as constants. Constant expressions may be of
2640 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2641 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2642 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2643
2644<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2645 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2646 <dd>Truncate a constant to another type. The bit size of CST must be larger
2647 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2648
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2649 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2650 <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]2651 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2652
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2653 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2654 <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]2655 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2656
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2657 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2658 <dd>Truncate a floating point constant to another floating point type. The
2659 size of CST must be larger than the size of TYPE. Both types must be
2660 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2661
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2662 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2663 <dd>Floating point extend a constant to another type. The size of CST must be
2664 smaller or equal to the size of TYPE. Both types must be floating
2665 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2666
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2667 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2668 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2669 constant. TYPE must be a scalar or vector integer type. CST must be of
2670 scalar or vector floating point type. Both CST and TYPE must be scalars,
2671 or vectors of the same number of elements. If the value won't fit in the
2672 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2673
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2674 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2675 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2676 constant. TYPE must be a scalar or vector integer type. CST must be of
2677 scalar or vector floating point type. Both CST and TYPE must be scalars,
2678 or vectors of the same number of elements. If the value won't fit in the
2679 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2680
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2681 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2682 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2683 constant. TYPE must be a scalar or vector floating point type. CST must be
2684 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2685 vectors of the same number of elements. If the value won't fit in the
2686 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2687
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2688 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2689 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2690 constant. TYPE must be a scalar or vector floating point type. CST must be
2691 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2692 vectors of the same number of elements. If the value won't fit in the
2693 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2694
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2695 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2696 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2697 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2698 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2699 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2700
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2701 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2702 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2703 type. CST must be of integer type. The CST value is zero extended,
2704 truncated, or unchanged to make it fit in a pointer size. This one is
2705 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2706
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2707 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2708 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2709 are the same as those for the <a href="#i_bitcast">bitcast
2710 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2711
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2712 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2713 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2714 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2715 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2716 instruction, the index list may have zero or more indexes, which are
2717 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2718
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2719 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2720 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2721
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2722 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2723 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2724
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2725 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2726 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2727
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2728 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2729 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2730 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2731
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2732 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2733 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2734 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2735
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2736 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2737 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2738 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2739
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2740 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2741 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2742 constants. The index list is interpreted in a similar manner as indices in
2743 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2744 index value must be specified.</dd>
2745
2746 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2747 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2748 constants. The index list is interpreted in a similar manner as indices in
2749 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2750 index value must be specified.</dd>
2751
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2752 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2753 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2754 be any of the <a href="#binaryops">binary</a>
2755 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2756 on operands are the same as those for the corresponding instruction
2757 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2758</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2759
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2760</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2761
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2762</div>
2763
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2764<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2765<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2766<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2767<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2768<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2769<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2770<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2771</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2772
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2773<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2774
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2775<p>LLVM supports inline assembler expressions (as opposed
2776 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2777 a special value. This value represents the inline assembler as a string
2778 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2779 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2780 expression has side effects, and a flag indicating whether the function
2781 containing the asm needs to align its stack conservatively. An example
2782 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2783
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2784<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2785i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2786</pre>
2787
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2788<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2789 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2790 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2791
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2792<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2793%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]2794</pre>
2795
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2796<p>Inline asms with side effects not visible in the constraint list must be
2797 marked as having side effects. This is done through the use of the
2798 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2799
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2800<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2801call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2802</pre>
2803
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2804<p>In some cases inline asms will contain code that will not work unless the
2805 stack is aligned in some way, such as calls or SSE instructions on x86,
2806 yet will not contain code that does that alignment within the asm.
2807 The compiler should make conservative assumptions about what the asm might
2808 contain and should generate its usual stack alignment code in the prologue
2809 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2810
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2811<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2812call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2813</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2814
2815<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2816 first.</p>
2817
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2818<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2819 documented here. Constraints on what can be done (e.g. duplication, moving,
2820 etc need to be documented). This is probably best done by reference to
2821 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2822
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2823<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2824<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2825</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2826
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2827<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2828
2829<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2830 attached to it that contains a list of constant integers. If present, the
2831 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2832 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2833 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2834 source code that produced it. For example:</p>
2835
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2836<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2837call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2838...
2839!42 = !{ i32 1234567 }
2840</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2841
2842<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]2843 IR. If the MDNode contains multiple constants, the code generator will use
2844 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]2845
2846</div>
2847
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2848</div>
2849
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2850<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2851<h3>
2852 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2853</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2854
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2855<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2856
2857<p>LLVM IR allows metadata to be attached to instructions in the program that
2858 can convey extra information about the code to the optimizers and code
2859 generator. One example application of metadata is source-level debug
2860 information. There are two metadata primitives: strings and nodes. All
2861 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2862 preceding exclamation point ('<tt>!</tt>').</p>
2863
2864<p>A metadata string is a string surrounded by double quotes. It can contain
2865 any character by escaping non-printable characters with "\xx" where "xx" is
2866 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2867
2868<p>Metadata nodes are represented with notation similar to structure constants
2869 (a comma separated list of elements, surrounded by braces and preceded by an
2870 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2871 10}</tt>". Metadata nodes can have any values as their operand.</p>
2872
2873<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2874 metadata nodes, which can be looked up in the module symbol table. For
2875 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2876
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2877<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2878 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2879
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2880<div class="doc_code">
2881<pre>
2882call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2883</pre>
2884</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2885
2886<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2887 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2888
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2889<div class="doc_code">
2890<pre>
2891%indvar.next = add i64 %indvar, 1, !dbg !21
2892</pre>
2893</div>
2894
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2895</div>
2896
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2897</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2898
2899<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2900<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2901 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2902</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2903<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2904<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2905<p>LLVM has a number of "magic" global variables that contain data that affect
2906code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2907of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2908section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2909by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2910
2911<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2912<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2913<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2914</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2915
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2916<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2917
2918<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2919href="#linkage_appending">appending linkage</a>. This array contains a list of
2920pointers to global variables and functions which may optionally have a pointer
2921cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2922
2923<pre>
2924 @X = global i8 4
2925 @Y = global i32 123
2926
2927 @llvm.used = appending global [2 x i8*] [
2928 i8* @X,
2929 i8* bitcast (i32* @Y to i8*)
2930 ], section "llvm.metadata"
2931</pre>
2932
2933<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2934compiler, assembler, and linker are required to treat the symbol as if there is
2935a reference to the global that it cannot see. For example, if a variable has
2936internal linkage and no references other than that from the <tt>@llvm.used</tt>
2937list, it cannot be deleted. This is commonly used to represent references from
2938inline asms and other things the compiler cannot "see", and corresponds to
2939"attribute((used))" in GNU C.</p>
2940
2941<p>On some targets, the code generator must emit a directive to the assembler or
2942object file to prevent the assembler and linker from molesting the symbol.</p>
2943
2944</div>
2945
2946<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2947<h3>
2948 <a name="intg_compiler_used">
2949 The '<tt>llvm.compiler.used</tt>' Global Variable
2950 </a>
2951</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2952
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2953<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2954
2955<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2956<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2957touching the symbol. On targets that support it, this allows an intelligent
2958linker to optimize references to the symbol without being impeded as it would be
2959by <tt>@llvm.used</tt>.</p>
2960
2961<p>This is a rare construct that should only be used in rare circumstances, and
2962should not be exposed to source languages.</p>
2963
2964</div>
2965
2966<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2967<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2968<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2969</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2970
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2971<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2972<pre>
2973%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2974@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2975</pre>
2976<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.
2977</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2978
2979</div>
2980
2981<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2982<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2983<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2984</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2985
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2986<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2987<pre>
2988%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2989@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2990</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2991
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2992<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.
2993</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2994
2995</div>
2996
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2997</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2998
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2999<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3000<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3001<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3002
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3003<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3004
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3005<p>The LLVM instruction set consists of several different classifications of
3006 instructions: <a href="#terminators">terminator
3007 instructions</a>, <a href="#binaryops">binary instructions</a>,
3008 <a href="#bitwiseops">bitwise binary instructions</a>,
3009 <a href="#memoryops">memory instructions</a>, and
3010 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3011
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3012<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3013<h3>
3014 <a name="terminators">Terminator Instructions</a>
3015</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3016
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3017<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3018
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3019<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3020 in a program ends with a "Terminator" instruction, which indicates which
3021 block should be executed after the current block is finished. These
3022 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3023 control flow, not values (the one exception being the
3024 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3025
Bill Wendlingad088e62011-07-30 05:42:50 +0000[diff] [blame]3026<p>There are seven different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3027 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
3028 '<a href="#i_br"><tt>br</tt></a>' instruction, the
3029 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]3030 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3031 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
Bill Wendlingad088e62011-07-30 05:42:50 +0000[diff] [blame]3032 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3033 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +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>
3037 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3038</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3039
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3040<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3041
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3042<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3043<pre>
3044 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]3045 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3046</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3047
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3048<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3049<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3050 a value) from a function back to the caller.</p>
3051
3052<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3053 value and then causes control flow, and one that just causes control flow to
3054 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3055
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3056<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3057<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3058 return value. The type of the return value must be a
3059 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3060
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3061<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3062 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3063 value or a return value with a type that does not match its type, or if it
3064 has a void return type and contains a '<tt>ret</tt>' instruction with a
3065 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3066
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3067<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3068<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3069 the calling function's context. If the caller is a
3070 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3071 instruction after the call. If the caller was an
3072 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3073 the beginning of the "normal" destination block. If the instruction returns
3074 a value, that value shall set the call or invoke instruction's return
3075 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3076
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3077<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3078<pre>
3079 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3080 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]3081 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]3082</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3083
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3084</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3085<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3086<h4>
3087 <a name="i_br">'<tt>br</tt>' Instruction</a>
3088</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3089
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3090<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3091
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3092<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3093<pre>
Bill Wendling16b86742011-07-26 10:41:15 +0000[diff] [blame]3094 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3095 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3096</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3097
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3098<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3099<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3100 different basic block in the current function. There are two forms of this
3101 instruction, corresponding to a conditional branch and an unconditional
3102 branch.</p>
3103
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3104<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3105<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3106 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3107 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3108 target.</p>
3109
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3110<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3111<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3112 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3113 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3114 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3115
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3116<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3117<pre>
3118Test:
3119 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3120 br i1 %cond, label %IfEqual, label %IfUnequal
3121IfEqual:
3122 <a href="#i_ret">ret</a> i32 1
3123IfUnequal:
3124 <a href="#i_ret">ret</a> i32 0
3125</pre>
3126
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3127</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3128
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3129<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3130<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3131 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3132</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3133
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3134<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3135
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3136<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3137<pre>
3138 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3139</pre>
3140
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3141<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3142<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]3143 several different places. It is a generalization of the '<tt>br</tt>'
3144 instruction, allowing a branch to occur to one of many possible
3145 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3146
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3147<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3148<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3149 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3150 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3151 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3152
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3153<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3154<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3155 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3156 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3157 transferred to the corresponding destination; otherwise, control flow is
3158 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3159
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3160<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3161<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3162 <tt>switch</tt> instruction, this instruction may be code generated in
3163 different ways. For example, it could be generated as a series of chained
3164 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3165
3166<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3167<pre>
3168 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3169 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3170 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3171
3172 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3173 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3174
3175 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3176 switch i32 %val, label %otherwise [ i32 0, label %onzero
3177 i32 1, label %onone
3178 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3179</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3180
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3181</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3182
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3183
3184<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3185<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3186 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3187</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3188
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3189<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3190
3191<h5>Syntax:</h5>
3192<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3193 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]3194</pre>
3195
3196<h5>Overview:</h5>
3197
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3198<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3199 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3200 "<tt>address</tt>". Address must be derived from a <a
3201 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3202
3203<h5>Arguments:</h5>
3204
3205<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3206 rest of the arguments indicate the full set of possible destinations that the
3207 address may point to. Blocks are allowed to occur multiple times in the
3208 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3209
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3210<p>This destination list is required so that dataflow analysis has an accurate
3211 understanding of the CFG.</p>
3212
3213<h5>Semantics:</h5>
3214
3215<p>Control transfers to the block specified in the address argument. All
3216 possible destination blocks must be listed in the label list, otherwise this
3217 instruction has undefined behavior. This implies that jumps to labels
3218 defined in other functions have undefined behavior as well.</p>
3219
3220<h5>Implementation:</h5>
3221
3222<p>This is typically implemented with a jump through a register.</p>
3223
3224<h5>Example:</h5>
3225<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3226 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3227</pre>
3228
3229</div>
3230
3231
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3232<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3233<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3234 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3235</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3236
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3237<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3238
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3239<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3240<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3241 &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]3242 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3243</pre>
3244
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3245<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3246<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3247 function, with the possibility of control flow transfer to either the
3248 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3249 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3250 control flow will return to the "normal" label. If the callee (or any
3251 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3252 instruction, control is interrupted and continued at the dynamically nearest
3253 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3254
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3255<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3256<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3257
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3258<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3259 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3260 convention</a> the call should use. If none is specified, the call
3261 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3262
3263 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3264 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3265 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3266
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3267 <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]3268 function value being invoked. In most cases, this is a direct function
3269 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3270 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3271
3272 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3273 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3274
3275 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3276 signature argument types and parameter attributes. All arguments must be
3277 of <a href="#t_firstclass">first class</a> type. If the function
3278 signature indicates the function accepts a variable number of arguments,
3279 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3280
3281 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3282 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3283
3284 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3285 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3286
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3287 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3288 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3289 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3290</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3291
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3292<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3293<p>This instruction is designed to operate as a standard
3294 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3295 primary difference is that it establishes an association with a label, which
3296 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3297
3298<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3299 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3300 exception. Additionally, this is important for implementation of
3301 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3302
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3303<p>For the purposes of the SSA form, the definition of the value returned by the
3304 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3305 block to the "normal" label. If the callee unwinds then no return value is
3306 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3307
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3308<p>Note that the code generator does not yet completely support unwind, and
3309that the invoke/unwind semantics are likely to change in future versions.</p>
3310
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3311<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3312<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3313 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3314 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3315 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3316 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3317</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3318
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3319</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3320
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3321<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3322
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3323<h4>
3324 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3325</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3326
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3327<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3328
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3329<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3330<pre>
3331 unwind
3332</pre>
3333
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3334<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3335<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3336 at the first callee in the dynamic call stack which used
3337 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3338 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3339
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3340<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3341<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3342 immediately halt. The dynamic call stack is then searched for the
3343 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3344 Once found, execution continues at the "exceptional" destination block
3345 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3346 instruction in the dynamic call chain, undefined behavior results.</p>
3347
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3348<p>Note that the code generator does not yet completely support unwind, and
3349that the invoke/unwind semantics are likely to change in future versions.</p>
3350
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3351</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3352
3353<!-- _______________________________________________________________________ -->
3354
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3355<h4>
3356 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3357</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3358
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3359<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3360
3361<h5>Syntax:</h5>
3362<pre>
3363 unreachable
3364</pre>
3365
3366<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3367<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3368 instruction is used to inform the optimizer that a particular portion of the
3369 code is not reachable. This can be used to indicate that the code after a
3370 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3371
3372<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3373<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3374
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3375</div>
3376
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3377</div>
3378
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3379<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3380<h3>
3381 <a name="binaryops">Binary Operations</a>
3382</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3383
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3384<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3385
3386<p>Binary operators are used to do most of the computation in a program. They
3387 require two operands of the same type, execute an operation on them, and
3388 produce a single value. The operands might represent multiple data, as is
3389 the case with the <a href="#t_vector">vector</a> data type. The result value
3390 has the same type as its operands.</p>
3391
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3392<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3393
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3394<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3395<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3396 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3397</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3398
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3399<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3400
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3401<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3402<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3403 &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]3404 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3405 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3406 &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]3407</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3408
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3409<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3410<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3411
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3412<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3413<p>The two arguments to the '<tt>add</tt>' instruction must
3414 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3415 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3416
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3417<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3418<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3419
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3420<p>If the sum has unsigned overflow, the result returned is the mathematical
3421 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]3422
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3423<p>Because LLVM integers use a two's complement representation, this instruction
3424 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3425
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3426<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3427 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3428 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3429 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3430 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3431
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3432<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3433<pre>
3434 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3435</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3436
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3437</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3438
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3439<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3440<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3441 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3442</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3443
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3444<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3445
3446<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3447<pre>
3448 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3449</pre>
3450
3451<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3452<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3453
3454<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3455<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3456 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3457 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3458
3459<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3460<p>The value produced is the floating point sum of the two operands.</p>
3461
3462<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3463<pre>
3464 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3465</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3466
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3467</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3468
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3469<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3470<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3471 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3472</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3473
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3474<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3475
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3476<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3477<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3478 &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]3479 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3480 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3481 &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]3482</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3483
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3484<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3485<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3486 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3487
3488<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3489 '<tt>neg</tt>' instruction present in most other intermediate
3490 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3491
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3492<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3493<p>The two arguments to the '<tt>sub</tt>' instruction must
3494 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3495 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3496
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3497<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3498<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3499
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3500<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3501 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3502 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3503
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3504<p>Because LLVM integers use a two's complement representation, this instruction
3505 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3506
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3507<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3508 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3509 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3510 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3511 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3512
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3513<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3514<pre>
3515 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3516 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3517</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3518
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3519</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3520
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3521<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3522<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3523 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3524</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3525
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3526<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3527
3528<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3529<pre>
3530 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3531</pre>
3532
3533<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3534<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3535 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3536
3537<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3538 '<tt>fneg</tt>' instruction present in most other intermediate
3539 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3540
3541<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3542<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3543 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3544 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3545
3546<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3547<p>The value produced is the floating point difference of the two operands.</p>
3548
3549<h5>Example:</h5>
3550<pre>
3551 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3552 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3553</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3554
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3555</div>
3556
3557<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3558<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3559 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3560</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3561
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3562<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3563
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3564<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3565<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3566 &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]3567 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3568 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3569 &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]3570</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3571
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3572<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3573<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3574
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3575<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3576<p>The two arguments to the '<tt>mul</tt>' instruction must
3577 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3578 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3579
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3580<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3581<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3582
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3583<p>If the result of the multiplication has unsigned overflow, the result
3584 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3585 width of the result.</p>
3586
3587<p>Because LLVM integers use a two's complement representation, and the result
3588 is the same width as the operands, this instruction returns the correct
3589 result for both signed and unsigned integers. If a full product
3590 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3591 be sign-extended or zero-extended as appropriate to the width of the full
3592 product.</p>
3593
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3594<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3595 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3596 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3597 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3598 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3599
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3600<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3601<pre>
3602 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3603</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3604
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3605</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3606
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3607<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3608<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3609 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3610</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3611
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3612<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3613
3614<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3615<pre>
3616 &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]3617</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3618
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3619<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3620<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3621
3622<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3623<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3624 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3625 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3626
3627<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3628<p>The value produced is the floating point product of the two operands.</p>
3629
3630<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3631<pre>
3632 &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]3633</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3634
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3635</div>
3636
3637<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3638<h4>
3639 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3640</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3641
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3642<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3643
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3644<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3645<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3646 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3647 &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]3648</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3649
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3650<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3651<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3652
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3653<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3654<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3655 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3656 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3657
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3658<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3659<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3660
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3661<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3662 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3663
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3664<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3665
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3666<p>If the <tt>exact</tt> keyword is present, the result value of the
3667 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3668 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3669
3670
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3671<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3672<pre>
3673 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3674</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3675
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3676</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3677
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3678<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3679<h4>
3680 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3681</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3682
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3683<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3684
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3685<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3686<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3687 &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]3688 &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]3689</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3690
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3691<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3692<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3693
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3694<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3695<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3696 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3697 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3698
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3699<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3700<p>The value produced is the signed integer quotient of the two operands rounded
3701 towards zero.</p>
3702
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3703<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3704 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3705
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3706<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3707 undefined behavior; this is a rare case, but can occur, for example, by doing
3708 a 32-bit division of -2147483648 by -1.</p>
3709
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3710<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3711 <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]3712 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3713
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3714<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3715<pre>
3716 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3717</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3718
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3719</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3720
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3721<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3722<h4>
3723 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3724</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3725
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3726<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3727
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3728<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3729<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3730 &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]3731</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3732
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3733<h5>Overview:</h5>
3734<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3735
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3736<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3737<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3738 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3739 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3740
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3741<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3742<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3743
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3744<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3745<pre>
3746 &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]3747</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3748
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3749</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3750
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3751<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3752<h4>
3753 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3754</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3755
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3756<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3757
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3758<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3759<pre>
3760 &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]3761</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3762
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3763<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3764<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3765 division of its two arguments.</p>
3766
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3767<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3768<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3769 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3770 values. Both arguments must have identical types.</p>
3771
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3772<h5>Semantics:</h5>
3773<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3774 This instruction always performs an unsigned division to get the
3775 remainder.</p>
3776
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3777<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3778 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3779
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3780<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3781
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3782<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3783<pre>
3784 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3785</pre>
3786
3787</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3788
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3789<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3790<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3791 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3792</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3793
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3794<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3795
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3796<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3797<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3798 &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]3799</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3800
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3801<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3802<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3803 division of its two operands. This instruction can also take
3804 <a href="#t_vector">vector</a> versions of the values in which case the
3805 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3806
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3807<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3808<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3809 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3810 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3811
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3812<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3813<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3814 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3815 <i>modulo</i> operator (where the result is either zero or has the same sign
3816 as the divisor, <tt>op2</tt>) of a value.
3817 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3818 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3819 Math Forum</a>. For a table of how this is implemented in various languages,
3820 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3821 Wikipedia: modulo operation</a>.</p>
3822
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3823<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3824 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3825
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3826<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3827 Overflow also leads to undefined behavior; this is a rare case, but can
3828 occur, for example, by taking the remainder of a 32-bit division of
3829 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3830 lets srem be implemented using instructions that return both the result of
3831 the division and the remainder.)</p>
3832
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3833<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3834<pre>
3835 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3836</pre>
3837
3838</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3839
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3840<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3841<h4>
3842 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3843</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3844
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3845<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3846
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3847<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3848<pre>
3849 &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]3850</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3851
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3852<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3853<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3854 its two operands.</p>
3855
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3856<h5>Arguments:</h5>
3857<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3858 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3859 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3860
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3861<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3862<p>This instruction returns the <i>remainder</i> of a division. The remainder
3863 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3864
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3865<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3866<pre>
3867 &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]3868</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3869
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3870</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3871
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3872</div>
3873
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3874<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3875<h3>
3876 <a name="bitwiseops">Bitwise Binary Operations</a>
3877</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3878
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3879<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3880
3881<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3882 program. They are generally very efficient instructions and can commonly be
3883 strength reduced from other instructions. They require two operands of the
3884 same type, execute an operation on them, and produce a single value. The
3885 resulting value is the same type as its operands.</p>
3886
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3887<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3888<h4>
3889 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3890</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3891
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3892<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3893
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3894<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3895<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3896 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3897 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3898 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3899 &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]3900</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3901
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3902<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3903<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3904 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3905
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3906<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3907<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3908 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3909 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3910
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3911<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3912<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3913 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3914 is (statically or dynamically) negative or equal to or larger than the number
3915 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3916 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3917 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3918
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3919<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3920 <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]3921 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3922 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3923 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3924 they would if the shift were expressed as a mul instruction with the same
3925 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3926
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3927<h5>Example:</h5>
3928<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3929 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3930 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3931 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3932 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3933 &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]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>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3937
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3938<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3939<h4>
3940 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3941</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3942
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3943<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3944
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3945<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3946<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3947 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3948 &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]3949</pre>
3950
3951<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3952<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3953 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3954
3955<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3956<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3957 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3958 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3959
3960<h5>Semantics:</h5>
3961<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3962 significant bits of the result will be filled with zero bits after the shift.
3963 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3964 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3965 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3966 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3967
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3968<p>If the <tt>exact</tt> keyword is present, the result value of the
3969 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3970 shifted out are non-zero.</p>
3971
3972
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3973<h5>Example:</h5>
3974<pre>
3975 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3976 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3977 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3978 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3979 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3980 &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]3981</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3982
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3983</div>
3984
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3985<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3986<h4>
3987 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3988</h4>
3989
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3990<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3991
3992<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3993<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3994 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3995 &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]3996</pre>
3997
3998<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3999<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4000 operand shifted to the right a specified number of bits with sign
4001 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4002
4003<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4004<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4005 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4006 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4007
4008<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4009<p>This instruction always performs an arithmetic shift right operation, The
4010 most significant bits of the result will be filled with the sign bit
4011 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4012 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4013 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4014 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4015
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4016<p>If the <tt>exact</tt> keyword is present, the result value of the
4017 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4018 shifted out are non-zero.</p>
4019
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4020<h5>Example:</h5>
4021<pre>
4022 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4023 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4024 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4025 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4026 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4027 &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]4028</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4029
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4030</div>
4031
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4032<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4033<h4>
4034 <a name="i_and">'<tt>and</tt>' Instruction</a>
4035</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4036
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4037<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4038
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4039<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4040<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4041 &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]4042</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4043
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4044<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4045<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4046 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4047
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4048<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4049<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4050 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4051 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4052
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4053<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4054<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4055
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4056<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4057 <tbody>
4058 <tr>
4059 <td>In0</td>
4060 <td>In1</td>
4061 <td>Out</td>
4062 </tr>
4063 <tr>
4064 <td>0</td>
4065 <td>0</td>
4066 <td>0</td>
4067 </tr>
4068 <tr>
4069 <td>0</td>
4070 <td>1</td>
4071 <td>0</td>
4072 </tr>
4073 <tr>
4074 <td>1</td>
4075 <td>0</td>
4076 <td>0</td>
4077 </tr>
4078 <tr>
4079 <td>1</td>
4080 <td>1</td>
4081 <td>1</td>
4082 </tr>
4083 </tbody>
4084</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4085
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4086<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4087<pre>
4088 &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]4089 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4090 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4091</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4092</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4093<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4094<h4>
4095 <a name="i_or">'<tt>or</tt>' Instruction</a>
4096</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4097
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4098<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4099
4100<h5>Syntax:</h5>
4101<pre>
4102 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4103</pre>
4104
4105<h5>Overview:</h5>
4106<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4107 two operands.</p>
4108
4109<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4110<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4111 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4112 values. Both arguments must have identical types.</p>
4113
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4114<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4115<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4116
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4117<table border="1" cellspacing="0" cellpadding="4">
4118 <tbody>
4119 <tr>
4120 <td>In0</td>
4121 <td>In1</td>
4122 <td>Out</td>
4123 </tr>
4124 <tr>
4125 <td>0</td>
4126 <td>0</td>
4127 <td>0</td>
4128 </tr>
4129 <tr>
4130 <td>0</td>
4131 <td>1</td>
4132 <td>1</td>
4133 </tr>
4134 <tr>
4135 <td>1</td>
4136 <td>0</td>
4137 <td>1</td>
4138 </tr>
4139 <tr>
4140 <td>1</td>
4141 <td>1</td>
4142 <td>1</td>
4143 </tr>
4144 </tbody>
4145</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4146
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4147<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4148<pre>
4149 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4150 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4151 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4152</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4153
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4154</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4155
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4156<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4157<h4>
4158 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4159</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4160
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4161<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4162
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4163<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4164<pre>
4165 &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]4166</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4167
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4168<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4169<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4170 its two operands. The <tt>xor</tt> is used to implement the "one's
4171 complement" operation, which is the "~" operator in C.</p>
4172
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4173<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4174<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4175 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4176 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4177
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4178<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4179<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4180
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4181<table border="1" cellspacing="0" cellpadding="4">
4182 <tbody>
4183 <tr>
4184 <td>In0</td>
4185 <td>In1</td>
4186 <td>Out</td>
4187 </tr>
4188 <tr>
4189 <td>0</td>
4190 <td>0</td>
4191 <td>0</td>
4192 </tr>
4193 <tr>
4194 <td>0</td>
4195 <td>1</td>
4196 <td>1</td>
4197 </tr>
4198 <tr>
4199 <td>1</td>
4200 <td>0</td>
4201 <td>1</td>
4202 </tr>
4203 <tr>
4204 <td>1</td>
4205 <td>1</td>
4206 <td>0</td>
4207 </tr>
4208 </tbody>
4209</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4210
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4211<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4212<pre>
4213 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4214 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4215 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4216 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4217</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4218
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4219</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4220
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4221</div>
4222
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4223<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4224<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4225 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4226</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4227
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4228<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4229
4230<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4231 target-independent manner. These instructions cover the element-access and
4232 vector-specific operations needed to process vectors effectively. While LLVM
4233 does directly support these vector operations, many sophisticated algorithms
4234 will want to use target-specific intrinsics to take full advantage of a
4235 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4236
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4237<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4238<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4239 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4240</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4241
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4242<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4243
4244<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4245<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4246 &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]4247</pre>
4248
4249<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4250<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4251 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4252
4253
4254<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4255<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4256 of <a href="#t_vector">vector</a> type. The second operand is an index
4257 indicating the position from which to extract the element. The index may be
4258 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4259
4260<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4261<p>The result is a scalar of the same type as the element type of
4262 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4263 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4264 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4265
4266<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4267<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4268 &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]4269</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4270
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4271</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4272
4273<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4274<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4275 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4276</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4277
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4278<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4279
4280<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4281<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4282 &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]4283</pre>
4284
4285<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4286<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4287 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4288
4289<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4290<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4291 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4292 whose type must equal the element type of the first operand. The third
4293 operand is an index indicating the position at which to insert the value.
4294 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4295
4296<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4297<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4298 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4299 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4300 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4301
4302<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4303<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4304 &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]4305</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4306
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4307</div>
4308
4309<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4310<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4311 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4312</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4313
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4314<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4315
4316<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4317<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4318 &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]4319</pre>
4320
4321<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4322<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4323 from two input vectors, returning a vector with the same element type as the
4324 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4325
4326<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4327<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4328 with types that match each other. The third argument is a shuffle mask whose
4329 element type is always 'i32'. The result of the instruction is a vector
4330 whose length is the same as the shuffle mask and whose element type is the
4331 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4332
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4333<p>The shuffle mask operand is required to be a constant vector with either
4334 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4335
4336<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4337<p>The elements of the two input vectors are numbered from left to right across
4338 both of the vectors. The shuffle mask operand specifies, for each element of
4339 the result vector, which element of the two input vectors the result element
4340 gets. The element selector may be undef (meaning "don't care") and the
4341 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4342
4343<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4344<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4345 &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]4346 &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]4347 &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]4348 &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]4349 &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]4350 &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]4351 &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]4352 &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]4353</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4354
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4355</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4356
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4357</div>
4358
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4359<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4360<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4361 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4362</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4363
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4364<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4365
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4366<p>LLVM supports several instructions for working with
4367 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4368
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4369<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4370<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4371 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4372</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4373
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4374<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4375
4376<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4377<pre>
4378 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4379</pre>
4380
4381<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4382<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4383 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4384
4385<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4386<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4387 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4388 <a href="#t_array">array</a> type. The operands are constant indices to
4389 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4390 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4391 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4392 <ul>
4393 <li>Since the value being indexed is not a pointer, the first index is
4394 omitted and assumed to be zero.</li>
4395 <li>At least one index must be specified.</li>
4396 <li>Not only struct indices but also array indices must be in
4397 bounds.</li>
4398 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4399
4400<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4401<p>The result is the value at the position in the aggregate specified by the
4402 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4403
4404<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4405<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4406 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4407</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4408
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4409</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4410
4411<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4412<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4413 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4414</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4415
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4416<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4417
4418<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4419<pre>
Bill Wendlingf6a91cf2011-07-26 20:42:28 +0000[diff] [blame]4420 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, &lt;idx&gt;}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4421</pre>
4422
4423<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4424<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4425 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4426
4427<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4428<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4429 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4430 <a href="#t_array">array</a> type. The second operand is a first-class
4431 value to insert. The following operands are constant indices indicating
4432 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]4433 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4434 value to insert must have the same type as the value identified by the
4435 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4436
4437<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4438<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4439 that of <tt>val</tt> except that the value at the position specified by the
4440 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4441
4442<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4443<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4444 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4445 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4446 %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]4447</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4448
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4449</div>
4450
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4451</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4452
4453<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4454<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4455 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4456</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4457
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4458<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4459
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4460<p>A key design point of an SSA-based representation is how it represents
4461 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4462 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4463 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4464
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4465<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4466<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4467 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4468</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4469
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4470<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4471
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4472<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4473<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4474 &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]4475</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4476
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4477<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4478<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4479 currently executing function, to be automatically released when this function
4480 returns to its caller. The object is always allocated in the generic address
4481 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4482
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4483<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4484<p>The '<tt>alloca</tt>' instruction
4485 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4486 runtime stack, returning a pointer of the appropriate type to the program.
4487 If "NumElements" is specified, it is the number of elements allocated,
4488 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4489 specified, the value result of the allocation is guaranteed to be aligned to
4490 at least that boundary. If not specified, or if zero, the target can choose
4491 to align the allocation on any convenient boundary compatible with the
4492 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4493
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4494<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4495
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4496<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4497<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4498 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4499 memory is automatically released when the function returns. The
4500 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4501 variables that must have an address available. When the function returns
4502 (either with the <tt><a href="#i_ret">ret</a></tt>
4503 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4504 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4505
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4506<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4507<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4508 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4509 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4510 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4511 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4512</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4513
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4514</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4515
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4516<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4517<h4>
4518 <a name="i_load">'<tt>load</tt>' Instruction</a>
4519</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4520
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4521<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4522
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4523<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4524<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4525 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4526 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4527 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4528</pre>
4529
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4530<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4531<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4532
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4533<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4534<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4535 from which to load. The pointer must point to
4536 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4537 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4538 number or order of execution of this <tt>load</tt> with other <a
4539 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4540
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4541<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4542 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]4543 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4544 alignment for the target. It is the responsibility of the code emitter to
4545 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4546 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4547 produce less efficient code. An alignment of 1 is always safe.</p>
4548
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4549<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4550 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4551 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4552 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4553 and code generator that this load is not expected to be reused in the cache.
4554 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4555 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4556
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4557<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4558<p>The location of memory pointed to is loaded. If the value being loaded is of
4559 scalar type then the number of bytes read does not exceed the minimum number
4560 of bytes needed to hold all bits of the type. For example, loading an
4561 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4562 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4563 is undefined if the value was not originally written using a store of the
4564 same type.</p>
4565
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4566<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4567<pre>
4568 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4569 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4570 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4571</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4572
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4573</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4574
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4575<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4576<h4>
4577 <a name="i_store">'<tt>store</tt>' Instruction</a>
4578</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4579
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4580<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4581
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4582<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4583<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4584 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>
4585 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]4586</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4587
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4588<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4589<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4590
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4591<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4592<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4593 and an address at which to store it. The type of the
4594 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4595 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4596 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4597 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4598 order of execution of this <tt>store</tt> with other <a
4599 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4600
4601<p>The optional constant "align" argument specifies the alignment of the
4602 operation (that is, the alignment of the memory address). A value of 0 or an
4603 omitted "align" argument means that the operation has the preferential
4604 alignment for the target. It is the responsibility of the code emitter to
4605 ensure that the alignment information is correct. Overestimating the
4606 alignment results in an undefined behavior. Underestimating the alignment may
4607 produce less efficient code. An alignment of 1 is always safe.</p>
4608
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4609<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4610 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4611 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4612 instruction tells the optimizer and code generator that this load is
4613 not expected to be reused in the cache. The code generator may
4614 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4615 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4616
4617
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4618<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4619<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4620 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4621 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4622 does not exceed the minimum number of bytes needed to hold all bits of the
4623 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4624 writing a value of a type like <tt>i20</tt> with a size that is not an
4625 integral number of bytes, it is unspecified what happens to the extra bits
4626 that do not belong to the type, but they will typically be overwritten.</p>
4627
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4628<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4629<pre>
4630 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4631 store i32 3, i32* %ptr <i>; yields {void}</i>
4632 %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]4633</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4634
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4635</div>
4636
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4637<!-- _______________________________________________________________________ -->
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]4638<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4639Instruction</a> </div>
4640
4641<div class="doc_text">
4642
4643<h5>Syntax:</h5>
4644<pre>
4645 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4646</pre>
4647
4648<h5>Overview:</h5>
4649<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4650between operations.</p>
4651
4652<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4653href="#ordering">ordering</a> argument which defines what
4654<i>synchronizes-with</i> edges they add. They can only be given
4655<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4656<code>seq_cst</code> orderings.</p>
4657
4658<h5>Semantics:</h5>
4659<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4660semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4661<code>acquire</code> ordering semantics if and only if there exist atomic
4662operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4663<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4664<var>X</var> modifies <var>M</var> (either directly or through some side effect
4665of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4666<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4667<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4668than an explicit <code>fence</code>, one (but not both) of the atomic operations
4669<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4670<code>acquire</code> (resp.) ordering constraint and still
4671<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4672<i>happens-before</i> edge.</p>
4673
4674<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4675having both <code>acquire</code> and <code>release</code> semantics specified
4676above, participates in the global program order of other <code>seq_cst</code>
4677operations and/or fences.</p>
4678
4679<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4680specifies that the fence only synchronizes with other fences in the same
4681thread. (This is useful for interacting with signal handlers.)</p>
4682
4683<p>FIXME: This instruction is a work in progress; until it is finished, use
4684 llvm.memory.barrier.
4685
4686<h5>Example:</h5>
4687<pre>
4688 fence acquire <i>; yields {void}</i>
4689 fence singlethread seq_cst <i>; yields {void}</i>
4690</pre>
4691
4692</div>
4693
4694<!-- _______________________________________________________________________ -->
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]4695<div class="doc_subsubsection"> <a name="i_cmpxchg">'<tt>cmpxchg</tt>'
4696Instruction</a> </div>
4697
4698<div class="doc_text">
4699
4700<h5>Syntax:</h5>
4701<pre>
4702 [volatile] cmpxchg &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;cmp&gt;, &lt;ty&gt; &lt;new&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
4703</pre>
4704
4705<h5>Overview:</h5>
4706<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4707It loads a value in memory and compares it to a given value. If they are
4708equal, it stores a new value into the memory.</p>
4709
4710<h5>Arguments:</h5>
4711<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4712address to operate on, a value to compare to the value currently be at that
4713address, and a new value to place at that address if the compared values are
4714equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4715bit width is a power of two greater than or equal to eight and less than
4716or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4717'<var>&lt;new&gt;</var>' must have the same type, and the type of
4718'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4719<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4720optimizer is not allowed to modify the number or order of execution
4721of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4722operations</a>.</p>
4723
4724<!-- FIXME: Extend allowed types. -->
4725
4726<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4727<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4728
4729<p>The optional "<code>singlethread</code>" argument declares that the
4730<code>cmpxchg</code> is only atomic with respect to code (usually signal
4731handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4732cmpxchg is atomic with respect to all other code in the system.</p>
4733
4734<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4735the size in memory of the operand.
4736
4737<h5>Semantics:</h5>
4738<p>The contents of memory at the location specified by the
4739'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4740'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4741'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4742is returned.
4743
4744<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4745purpose of identifying <a href="#release_sequence">release sequences</a>. A
4746failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4747parameter determined by dropping any <code>release</code> part of the
4748<code>cmpxchg</code>'s ordering.</p>
4749
4750<!--
4751FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4752optimization work on ARM.)
4753
4754FIXME: Is a weaker ordering constraint on failure helpful in practice?
4755-->
4756
4757<h5>Example:</h5>
4758<pre>
4759entry:
4760 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4761 <a href="#i_br">br</a> label %loop
4762
4763loop:
4764 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4765 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4766 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4767 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4768 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4769
4770done:
4771 ...
4772</pre>
4773
4774</div>
4775
4776<!-- _______________________________________________________________________ -->
4777<div class="doc_subsubsection"> <a name="i_atomicrmw">'<tt>atomicrmw</tt>'
4778Instruction</a> </div>
4779
4780<div class="doc_text">
4781
4782<h5>Syntax:</h5>
4783<pre>
4784 [volatile] atomicrmw &lt;operation&gt; &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;value&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
4785</pre>
4786
4787<h5>Overview:</h5>
4788<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4789
4790<h5>Arguments:</h5>
4791<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4792operation to apply, an address whose value to modify, an argument to the
4793operation. The operation must be one of the following keywords:</p>
4794<ul>
4795 <li>xchg</li>
4796 <li>add</li>
4797 <li>sub</li>
4798 <li>and</li>
4799 <li>nand</li>
4800 <li>or</li>
4801 <li>xor</li>
4802 <li>max</li>
4803 <li>min</li>
4804 <li>umax</li>
4805 <li>umin</li>
4806</ul>
4807
4808<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4809bit width is a power of two greater than or equal to eight and less than
4810or equal to a target-specific size limit. The type of the
4811'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4812If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4813optimizer is not allowed to modify the number or order of execution of this
4814<code>atomicrmw</code> with other <a href="#volatile">volatile
4815 operations</a>.</p>
4816
4817<!-- FIXME: Extend allowed types. -->
4818
4819<h5>Semantics:</h5>
4820<p>The contents of memory at the location specified by the
4821'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4822back. The original value at the location is returned. The modification is
4823specified by the <var>operation</var> argument:</p>
4824
4825<ul>
4826 <li>xchg: <code>*ptr = val</code></li>
4827 <li>add: <code>*ptr = *ptr + val</code></li>
4828 <li>sub: <code>*ptr = *ptr - val</code></li>
4829 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4830 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4831 <li>or: <code>*ptr = *ptr | val</code></li>
4832 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4833 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4834 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4835 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4836 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4837</ul>
4838
4839<h5>Example:</h5>
4840<pre>
4841 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4842</pre>
4843
4844</div>
4845
4846<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4847<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4848 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4849</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4850
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4851<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4852
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4853<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4854<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4855 &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]4856 &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]4857</pre>
4858
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4859<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4860<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4861 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4862 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4863
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4864<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4865<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4866 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4867 elements of the aggregate object are indexed. The interpretation of each
4868 index is dependent on the type being indexed into. The first index always
4869 indexes the pointer value given as the first argument, the second index
4870 indexes a value of the type pointed to (not necessarily the value directly
4871 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4872 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4873 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4874 can never be pointers, since that would require loading the pointer before
4875 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4876
4877<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]4878 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4879 integer <b>constants</b> are allowed. When indexing into an array, pointer
4880 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]4881 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4882
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4883<p>For example, let's consider a C code fragment and how it gets compiled to
4884 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4885
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4886<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4887struct RT {
4888 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4889 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4890 char C;
4891};
4892struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4893 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4894 double Y;
4895 struct RT Z;
4896};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4897
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4898int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4899 return &amp;s[1].Z.B[5][13];
4900}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4901</pre>
4902
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4903<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4904
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4905<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4906%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4907%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4908
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4909define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4910entry:
4911 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4912 ret i32* %reg
4913}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4914</pre>
4915
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4916<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4917<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]4918 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4919 }</tt>' type, a structure. The second index indexes into the third element
4920 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4921 i8 }</tt>' type, another structure. The third index indexes into the second
4922 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4923 array. The two dimensions of the array are subscripted into, yielding an
4924 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4925 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4926
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4927<p>Note that it is perfectly legal to index partially through a structure,
4928 returning a pointer to an inner element. Because of this, the LLVM code for
4929 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4930
4931<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4932 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4933 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4934 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4935 %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]4936 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4937 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4938 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4939 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4940</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4941
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4942<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4943 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4944 base pointer is not an <i>in bounds</i> address of an allocated object,
4945 or if any of the addresses that would be formed by successive addition of
4946 the offsets implied by the indices to the base address with infinitely
4947 precise arithmetic are not an <i>in bounds</i> address of that allocated
4948 object. The <i>in bounds</i> addresses for an allocated object are all
4949 the addresses that point into the object, plus the address one byte past
4950 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4951
4952<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4953 the base address with silently-wrapping two's complement arithmetic, and
4954 the result value of the <tt>getelementptr</tt> may be outside the object
4955 pointed to by the base pointer. The result value may not necessarily be
4956 used to access memory though, even if it happens to point into allocated
4957 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4958 section for more information.</p>
4959
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4960<p>The getelementptr instruction is often confusing. For some more insight into
4961 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4962
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4963<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4964<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4965 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4966 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4967 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4968 %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]4969 <i>; yields i8*:eptr</i>
4970 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4971 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4972 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4973</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4974
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4975</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4976
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4977</div>
4978
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4979<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4980<h3>
4981 <a name="convertops">Conversion Operations</a>
4982</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4983
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4984<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4985
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4986<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4987 which all take a single operand and a type. They perform various bit
4988 conversions on the operand.</p>
4989
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4990<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4991<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4992 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4993</h4>
4994
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4995<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4996
4997<h5>Syntax:</h5>
4998<pre>
4999 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5000</pre>
5001
5002<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5003<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5004 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5005
5006<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5007<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5008 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5009 of the same number of integers.
5010 The bit size of the <tt>value</tt> must be larger than
5011 the bit size of the destination type, <tt>ty2</tt>.
5012 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5013
5014<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5015<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5016 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5017 source size must be larger than the destination size, <tt>trunc</tt> cannot
5018 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5019
5020<h5>Example:</h5>
5021<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5022 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5023 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5024 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5025 %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]5026</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5027
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5028</div>
5029
5030<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5031<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5032 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5033</h4>
5034
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5035<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5036
5037<h5>Syntax:</h5>
5038<pre>
5039 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5040</pre>
5041
5042<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5043<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5044 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5045
5046
5047<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5048<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5049 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5050 of the same number of integers.
5051 The bit size of the <tt>value</tt> must be smaller than
5052 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5053 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5054
5055<h5>Semantics:</h5>
5056<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]5057 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5058
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]5059<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]5060
5061<h5>Example:</h5>
5062<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5063 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5064 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5065 %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]5066</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5067
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5068</div>
5069
5070<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5071<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5072 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5073</h4>
5074
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5075<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5076
5077<h5>Syntax:</h5>
5078<pre>
5079 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5080</pre>
5081
5082<h5>Overview:</h5>
5083<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5084
5085<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5086<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5087 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5088 of the same number of integers.
5089 The bit size of the <tt>value</tt> must be smaller than
5090 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5091 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5092
5093<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5094<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5095 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5096 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5097
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5098<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]5099
5100<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5101<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5102 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5103 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5104 %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]5105</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5106
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5107</div>
5108
5109<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5110<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5111 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5112</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5113
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5114<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5115
5116<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5117<pre>
5118 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5119</pre>
5120
5121<h5>Overview:</h5>
5122<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5123 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5124
5125<h5>Arguments:</h5>
5126<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5127 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5128 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]5129 <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]5130 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5131
5132<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5133<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5134 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5135 <a href="#t_floating">floating point</a> type. If the value cannot fit
5136 within the destination type, <tt>ty2</tt>, then the results are
5137 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5138
5139<h5>Example:</h5>
5140<pre>
5141 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5142 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5143</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5144
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5145</div>
5146
5147<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5148<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5149 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5150</h4>
5151
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5152<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5153
5154<h5>Syntax:</h5>
5155<pre>
5156 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5157</pre>
5158
5159<h5>Overview:</h5>
5160<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]5161 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5162
5163<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5164<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5165 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5166 a <a href="#t_floating">floating point</a> type to cast it to. The source
5167 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5168
5169<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5170<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5171 <a href="#t_floating">floating point</a> type to a larger
5172 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5173 used to make a <i>no-op cast</i> because it always changes bits. Use
5174 <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]5175
5176<h5>Example:</h5>
5177<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]5178 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5179 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5180</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5181
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5182</div>
5183
5184<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5185<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]5186 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5187</h4>
5188
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5189<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5190
5191<h5>Syntax:</h5>
5192<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5193 &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]5194</pre>
5195
5196<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5197<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5198 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5199
5200<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5201<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5202 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5203 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5204 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5205 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5206
5207<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5208<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5209 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5210 towards zero) unsigned integer value. If the value cannot fit
5211 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5212
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5213<h5>Example:</h5>
5214<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5215 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5216 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5217 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5218</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5219
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5220</div>
5221
5222<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5223<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5224 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5225</h4>
5226
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5227<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5228
5229<h5>Syntax:</h5>
5230<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5231 &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]5232</pre>
5233
5234<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5235<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5236 <a href="#t_floating">floating point</a> <tt>value</tt> to
5237 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5238
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5239<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5240<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5241 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5242 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5243 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5244 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5245
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5246<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5247<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5248 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5249 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5250 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5251
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5252<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5253<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5254 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5255 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5256 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5257</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5258
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5259</div>
5260
5261<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5262<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5263 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5264</h4>
5265
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5266<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5267
5268<h5>Syntax:</h5>
5269<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5270 &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]5271</pre>
5272
5273<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5274<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5275 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5276
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5277<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5278<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]5279 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5280 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5281 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5282 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5283
5284<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5285<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5286 integer quantity and converts it to the corresponding floating point
5287 value. If the value cannot fit in the floating point value, the results are
5288 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5289
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5290<h5>Example:</h5>
5291<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5292 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5293 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5294</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5295
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5296</div>
5297
5298<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5299<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5300 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5301</h4>
5302
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5303<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5304
5305<h5>Syntax:</h5>
5306<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5307 &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]5308</pre>
5309
5310<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5311<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5312 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5313
5314<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5315<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]5316 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5317 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5318 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5319 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5320
5321<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5322<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5323 quantity and converts it to the corresponding floating point value. If the
5324 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5325
5326<h5>Example:</h5>
5327<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5328 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5329 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5330</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5331
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5332</div>
5333
5334<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5335<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5336 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5337</h4>
5338
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5339<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5340
5341<h5>Syntax:</h5>
5342<pre>
5343 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5344</pre>
5345
5346<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5347<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5348 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5349
5350<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5351<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5352 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5353 <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]5354
5355<h5>Semantics:</h5>
5356<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5357 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5358 truncating or zero extending that value to the size of the integer type. If
5359 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5360 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5361 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5362 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5363
5364<h5>Example:</h5>
5365<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5366 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5367 %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]5368</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5369
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5370</div>
5371
5372<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5373<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5374 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5375</h4>
5376
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5377<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5378
5379<h5>Syntax:</h5>
5380<pre>
5381 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5382</pre>
5383
5384<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5385<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5386 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5387
5388<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5389<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5390 value to cast, and a type to cast it to, which must be a
5391 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5392
5393<h5>Semantics:</h5>
5394<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5395 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5396 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5397 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5398 than the size of a pointer then a zero extension is done. If they are the
5399 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5400
5401<h5>Example:</h5>
5402<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5403 %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]5404 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5405 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5406</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5407
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5408</div>
5409
5410<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5411<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5412 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5413</h4>
5414
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5415<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5416
5417<h5>Syntax:</h5>
5418<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5419 &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]5420</pre>
5421
5422<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5423<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5424 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5425
5426<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5427<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5428 non-aggregate first class value, and a type to cast it to, which must also be
5429 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5430 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5431 identical. If the source type is a pointer, the destination type must also be
5432 a pointer. This instruction supports bitwise conversion of vectors to
5433 integers and to vectors of other types (as long as they have the same
5434 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5435
5436<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5437<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5438 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5439 this conversion. The conversion is done as if the <tt>value</tt> had been
5440 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5441 be converted to other pointer types with this instruction. To convert
5442 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5443 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5444
5445<h5>Example:</h5>
5446<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5447 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5448 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5449 %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]5450</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5451
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5452</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5453
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5454</div>
5455
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5456<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5457<h3>
5458 <a name="otherops">Other Operations</a>
5459</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5460
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5461<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5462
5463<p>The instructions in this category are the "miscellaneous" instructions, which
5464 defy better classification.</p>
5465
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5466<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5467<h4>
5468 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5469</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5470
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5471<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5472
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5473<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5474<pre>
5475 &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]5476</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5477
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5478<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5479<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5480 boolean values based on comparison of its two integer, integer vector, or
5481 pointer operands.</p>
5482
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5483<h5>Arguments:</h5>
5484<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5485 the condition code indicating the kind of comparison to perform. It is not a
5486 value, just a keyword. The possible condition code are:</p>
5487
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5488<ol>
5489 <li><tt>eq</tt>: equal</li>
5490 <li><tt>ne</tt>: not equal </li>
5491 <li><tt>ugt</tt>: unsigned greater than</li>
5492 <li><tt>uge</tt>: unsigned greater or equal</li>
5493 <li><tt>ult</tt>: unsigned less than</li>
5494 <li><tt>ule</tt>: unsigned less or equal</li>
5495 <li><tt>sgt</tt>: signed greater than</li>
5496 <li><tt>sge</tt>: signed greater or equal</li>
5497 <li><tt>slt</tt>: signed less than</li>
5498 <li><tt>sle</tt>: signed less or equal</li>
5499</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5500
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5501<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5502 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5503 typed. They must also be identical types.</p>
5504
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5505<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5506<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5507 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5508 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]5509 result, as follows:</p>
5510
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5511<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5512 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5513 <tt>false</tt> otherwise. No sign interpretation is necessary or
5514 performed.</li>
5515
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5516 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5517 <tt>false</tt> otherwise. No sign interpretation is necessary or
5518 performed.</li>
5519
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5520 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5521 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5522
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5523 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5524 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5525 to <tt>op2</tt>.</li>
5526
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5527 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5528 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5529
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5530 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5531 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5532
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5533 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5534 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5535
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5536 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5537 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5538 to <tt>op2</tt>.</li>
5539
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5540 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5541 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5542
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5543 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5544 <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]5545</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5546
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5547<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5548 values are compared as if they were integers.</p>
5549
5550<p>If the operands are integer vectors, then they are compared element by
5551 element. The result is an <tt>i1</tt> vector with the same number of elements
5552 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5553
5554<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5555<pre>
5556 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5557 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5558 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5559 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5560 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5561 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5562</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5563
5564<p>Note that the code generator does not yet support vector types with
5565 the <tt>icmp</tt> instruction.</p>
5566
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5567</div>
5568
5569<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5570<h4>
5571 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5572</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5573
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5574<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5575
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5576<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5577<pre>
5578 &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]5579</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5580
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5581<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5582<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5583 values based on comparison of its operands.</p>
5584
5585<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]5586(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5587
5588<p>If the operands are floating point vectors, then the result type is a vector
5589 of boolean with the same number of elements as the operands being
5590 compared.</p>
5591
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5592<h5>Arguments:</h5>
5593<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5594 the condition code indicating the kind of comparison to perform. It is not a
5595 value, just a keyword. The possible condition code are:</p>
5596
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5597<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5598 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5599 <li><tt>oeq</tt>: ordered and equal</li>
5600 <li><tt>ogt</tt>: ordered and greater than </li>
5601 <li><tt>oge</tt>: ordered and greater than or equal</li>
5602 <li><tt>olt</tt>: ordered and less than </li>
5603 <li><tt>ole</tt>: ordered and less than or equal</li>
5604 <li><tt>one</tt>: ordered and not equal</li>
5605 <li><tt>ord</tt>: ordered (no nans)</li>
5606 <li><tt>ueq</tt>: unordered or equal</li>
5607 <li><tt>ugt</tt>: unordered or greater than </li>
5608 <li><tt>uge</tt>: unordered or greater than or equal</li>
5609 <li><tt>ult</tt>: unordered or less than </li>
5610 <li><tt>ule</tt>: unordered or less than or equal</li>
5611 <li><tt>une</tt>: unordered or not equal</li>
5612 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5613 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5614</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5615
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5616<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5617 <i>unordered</i> means that either operand may be a QNAN.</p>
5618
5619<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5620 a <a href="#t_floating">floating point</a> type or
5621 a <a href="#t_vector">vector</a> of floating point type. They must have
5622 identical types.</p>
5623
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5624<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5625<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5626 according to the condition code given as <tt>cond</tt>. If the operands are
5627 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5628 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5629 follows:</p>
5630
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5631<ol>
5632 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5633
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5634 <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]5635 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5636
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5637 <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]5638 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5639
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5640 <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]5641 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5642
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5643 <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]5644 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5645
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5646 <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]5647 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5648
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5649 <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]5650 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5651
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5652 <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]5653
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5654 <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]5655 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5656
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5657 <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]5658 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5659
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5660 <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]5661 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5662
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5663 <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]5664 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5665
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5666 <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]5667 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5668
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5669 <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]5670 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5671
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5672 <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]5673
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5674 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5675</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5676
5677<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5678<pre>
5679 &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]5680 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5681 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5682 &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]5683</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5684
5685<p>Note that the code generator does not yet support vector types with
5686 the <tt>fcmp</tt> instruction.</p>
5687
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5688</div>
5689
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5690<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5691<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5692 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5693</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5694
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5695<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5696
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5697<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5698<pre>
5699 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5700</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5701
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5702<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5703<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5704 SSA graph representing the function.</p>
5705
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5706<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5707<p>The type of the incoming values is specified with the first type field. After
5708 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5709 one pair for each predecessor basic block of the current block. Only values
5710 of <a href="#t_firstclass">first class</a> type may be used as the value
5711 arguments to the PHI node. Only labels may be used as the label
5712 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5713
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5714<p>There must be no non-phi instructions between the start of a basic block and
5715 the PHI instructions: i.e. PHI instructions must be first in a basic
5716 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5717
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5718<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5719 occur on the edge from the corresponding predecessor block to the current
5720 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5721 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5722
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5723<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5724<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5725 specified by the pair corresponding to the predecessor basic block that
5726 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5727
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5728<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5729<pre>
5730Loop: ; Infinite loop that counts from 0 on up...
5731 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5732 %nextindvar = add i32 %indvar, 1
5733 br label %Loop
5734</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5735
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5736</div>
5737
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5738<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5739<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5740 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5741</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5742
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5743<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5744
5745<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5746<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5747 &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>
5748
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5749 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5750</pre>
5751
5752<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5753<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5754 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5755
5756
5757<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5758<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5759 values indicating the condition, and two values of the
5760 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5761 vectors and the condition is a scalar, then entire vectors are selected, not
5762 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5763
5764<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5765<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5766 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5767
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5768<p>If the condition is a vector of i1, then the value arguments must be vectors
5769 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5770
5771<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5772<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5773 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5774</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5775
5776<p>Note that the code generator does not yet support conditions
5777 with vector type.</p>
5778
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5779</div>
5780
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5781<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5782<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5783 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5784</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5785
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5786<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5787
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5788<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5789<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5790 &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]5791</pre>
5792
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5793<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5794<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5795
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5796<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5797<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5798
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5799<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5800 <li>The optional "tail" marker indicates that the callee function does not
5801 access any allocas or varargs in the caller. Note that calls may be
5802 marked "tail" even if they do not occur before
5803 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5804 present, the function call is eligible for tail call optimization,
5805 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5806 optimized into a jump</a>. The code generator may optimize calls marked
5807 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5808 sibling call optimization</a> when the caller and callee have
5809 matching signatures, or 2) forced tail call optimization when the
5810 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5811 <ul>
5812 <li>Caller and callee both have the calling
5813 convention <tt>fastcc</tt>.</li>
5814 <li>The call is in tail position (ret immediately follows call and ret
5815 uses value of call or is void).</li>
5816 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5817 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5818 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5819 constraints are met.</a></li>
5820 </ul>
5821 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5822
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5823 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5824 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5825 defaults to using C calling conventions. The calling convention of the
5826 call must match the calling convention of the target function, or else the
5827 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5828
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5829 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5830 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5831 '<tt>inreg</tt>' attributes are valid here.</li>
5832
5833 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5834 type of the return value. Functions that return no value are marked
5835 <tt><a href="#t_void">void</a></tt>.</li>
5836
5837 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5838 being invoked. The argument types must match the types implied by this
5839 signature. This type can be omitted if the function is not varargs and if
5840 the function type does not return a pointer to a function.</li>
5841
5842 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5843 be invoked. In most cases, this is a direct function invocation, but
5844 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5845 to function value.</li>
5846
5847 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5848 signature argument types and parameter attributes. All arguments must be
5849 of <a href="#t_firstclass">first class</a> type. If the function
5850 signature indicates the function accepts a variable number of arguments,
5851 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5852
5853 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5854 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5855 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5856</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5857
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5858<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5859<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5860 a specified function, with its incoming arguments bound to the specified
5861 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5862 function, control flow continues with the instruction after the function
5863 call, and the return value of the function is bound to the result
5864 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5865
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5866<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5867<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5868 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5869 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5870 %X = tail call i32 @foo() <i>; yields i32</i>
5871 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5872 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5873
5874 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5875 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5876 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5877 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5878 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5879 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5880</pre>
5881
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5882<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5883standard C99 library as being the C99 library functions, and may perform
5884optimizations or generate code for them under that assumption. This is
5885something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5886freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5887
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5888</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5889
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5890<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5891<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5892 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5893</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5894
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5895<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5896
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5897<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5898<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5899 &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]5900</pre>
5901
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5902<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5903<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5904 the "variable argument" area of a function call. It is used to implement the
5905 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5906
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5907<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5908<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5909 argument. It returns a value of the specified argument type and increments
5910 the <tt>va_list</tt> to point to the next argument. The actual type
5911 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5912
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5913<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5914<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5915 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5916 to the next argument. For more information, see the variable argument
5917 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5918
5919<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]5920 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5921 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5922
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5923<p><tt>va_arg</tt> is an LLVM instruction instead of
5924 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5925 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5926
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5927<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5928<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5929
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5930<p>Note that the code generator does not yet fully support va_arg on many
5931 targets. Also, it does not currently support va_arg with aggregate types on
5932 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5933
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5934</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5935
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5936</div>
5937
5938</div>
5939
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5940<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5941<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5942<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5943
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5944<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5945
5946<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5947 well known names and semantics and are required to follow certain
5948 restrictions. Overall, these intrinsics represent an extension mechanism for
5949 the LLVM language that does not require changing all of the transformations
5950 in LLVM when adding to the language (or the bitcode reader/writer, the
5951 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5952
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5953<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5954 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5955 begin with this prefix. Intrinsic functions must always be external
5956 functions: you cannot define the body of intrinsic functions. Intrinsic
5957 functions may only be used in call or invoke instructions: it is illegal to
5958 take the address of an intrinsic function. Additionally, because intrinsic
5959 functions are part of the LLVM language, it is required if any are added that
5960 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5961
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5962<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5963 family of functions that perform the same operation but on different data
5964 types. Because LLVM can represent over 8 million different integer types,
5965 overloading is used commonly to allow an intrinsic function to operate on any
5966 integer type. One or more of the argument types or the result type can be
5967 overloaded to accept any integer type. Argument types may also be defined as
5968 exactly matching a previous argument's type or the result type. This allows
5969 an intrinsic function which accepts multiple arguments, but needs all of them
5970 to be of the same type, to only be overloaded with respect to a single
5971 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5972
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5973<p>Overloaded intrinsics will have the names of its overloaded argument types
5974 encoded into its function name, each preceded by a period. Only those types
5975 which are overloaded result in a name suffix. Arguments whose type is matched
5976 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5977 can take an integer of any width and returns an integer of exactly the same
5978 integer width. This leads to a family of functions such as
5979 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5980 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5981 suffix is required. Because the argument's type is matched against the return
5982 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5983
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5984<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5985 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5986
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5987<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5988<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5989 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5990</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5991
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5992<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5993
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5994<p>Variable argument support is defined in LLVM with
5995 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5996 intrinsic functions. These functions are related to the similarly named
5997 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5998
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5999<p>All of these functions operate on arguments that use a target-specific value
6000 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6001 not define what this type is, so all transformations should be prepared to
6002 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6003
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]6004<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]6005 instruction and the variable argument handling intrinsic functions are
6006 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6007
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]6008<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6009define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6010 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6011 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6012 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6013 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6014
6015 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6016 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6017
6018 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6019 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6020 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6021 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6022 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6023
6024 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6025 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]6026 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6027}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6028
6029declare void @llvm.va_start(i8*)
6030declare void @llvm.va_copy(i8*, i8*)
6031declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6032</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6033
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6034<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6035<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6036 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6037</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6038
6039
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6040<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6041
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6042<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6043<pre>
6044 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6045</pre>
6046
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6047<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6048<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6049 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]6050
6051<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6052<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]6053
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6054<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6055<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]6056 macro available in C. In a target-dependent way, it initializes
6057 the <tt>va_list</tt> element to which the argument points, so that the next
6058 call to <tt>va_arg</tt> will produce the first variable argument passed to
6059 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6060 need to know the last argument of the function as the compiler can figure
6061 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6062
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6063</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6064
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6065<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6066<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6067 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6068</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6069
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6070<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6071
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6072<h5>Syntax:</h5>
6073<pre>
6074 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6075</pre>
6076
6077<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6078<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6079 which has been initialized previously
6080 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6081 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6082
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6083<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6084<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]6085
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6086<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6087<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]6088 macro available in C. In a target-dependent way, it destroys
6089 the <tt>va_list</tt> element to which the argument points. Calls
6090 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6091 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6092 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6093
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6094</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6095
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6096<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6097<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6098 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6099</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6100
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6101<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6102
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6103<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6104<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6105 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6106</pre>
6107
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6108<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6109<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6110 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6111
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6112<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6113<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]6114 The second argument is a pointer to a <tt>va_list</tt> element to copy
6115 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6116
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6117<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6118<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]6119 macro available in C. In a target-dependent way, it copies the
6120 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6121 element. This intrinsic is necessary because
6122 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6123 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6124
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6125</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6126
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6127</div>
6128
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6129<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6130<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6131 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6132</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6133
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6134<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6135
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6136<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]6137Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6138intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6139roots on the stack</a>, as well as garbage collector implementations that
6140require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6141barriers. Front-ends for type-safe garbage collected languages should generate
6142these intrinsics to make use of the LLVM garbage collectors. For more details,
6143see <a href="GarbageCollection.html">Accurate Garbage Collection with
6144LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6145
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6146<p>The garbage collection intrinsics only operate on objects in the generic
6147 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6148
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6149<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6150<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6151 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6152</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6153
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6154<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6155
6156<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6157<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6158 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6159</pre>
6160
6161<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]6162<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]6163 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6164
6165<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6166<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6167 root pointer. The second pointer (which must be either a constant or a
6168 global value address) contains the meta-data to be associated with the
6169 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6170
6171<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]6172<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]6173 location. At compile-time, the code generator generates information to allow
6174 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6175 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6176 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6177
6178</div>
6179
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6180<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6181<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6182 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6183</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6184
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6185<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6186
6187<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6188<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6189 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6190</pre>
6191
6192<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6193<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6194 locations, allowing garbage collector implementations that require read
6195 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6196
6197<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6198<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]6199 allocated from the garbage collector. The first object is a pointer to the
6200 start of the referenced object, if needed by the language runtime (otherwise
6201 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6202
6203<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6204<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6205 instruction, but may be replaced with substantially more complex code by the
6206 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6207 may only be used in a function which <a href="#gc">specifies a GC
6208 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6209
6210</div>
6211
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6212<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6213<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6214 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6215</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6216
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6217<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6218
6219<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6220<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6221 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6222</pre>
6223
6224<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6225<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6226 locations, allowing garbage collector implementations that require write
6227 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6228
6229<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6230<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]6231 object to store it to, and the third is the address of the field of Obj to
6232 store to. If the runtime does not require a pointer to the object, Obj may
6233 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6234
6235<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6236<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6237 instruction, but may be replaced with substantially more complex code by the
6238 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6239 may only be used in a function which <a href="#gc">specifies a GC
6240 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6241
6242</div>
6243
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6244</div>
6245
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6246<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6247<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6248 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6249</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6250
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6251<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6252
6253<p>These intrinsics are provided by LLVM to expose special features that may
6254 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6255
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6256<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6257<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6258 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6259</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6260
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6261<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6262
6263<h5>Syntax:</h5>
6264<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6265 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6266</pre>
6267
6268<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6269<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6270 target-specific value indicating the return address of the current function
6271 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6272
6273<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6274<p>The argument to this intrinsic indicates which function to return the address
6275 for. Zero indicates the calling function, one indicates its caller, etc.
6276 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6277
6278<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6279<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6280 indicating the return address of the specified call frame, or zero if it
6281 cannot be identified. The value returned by this intrinsic is likely to be
6282 incorrect or 0 for arguments other than zero, so it should only be used for
6283 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6284
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6285<p>Note that calling this intrinsic does not prevent function inlining or other
6286 aggressive transformations, so the value returned may not be that of the
6287 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6288
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6289</div>
6290
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6291<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6292<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6293 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6294</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6295
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6296<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6297
6298<h5>Syntax:</h5>
6299<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6300 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6301</pre>
6302
6303<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6304<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6305 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6306
6307<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6308<p>The argument to this intrinsic indicates which function to return the frame
6309 pointer for. Zero indicates the calling function, one indicates its caller,
6310 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6311
6312<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6313<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6314 indicating the frame address of the specified call frame, or zero if it
6315 cannot be identified. The value returned by this intrinsic is likely to be
6316 incorrect or 0 for arguments other than zero, so it should only be used for
6317 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6318
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6319<p>Note that calling this intrinsic does not prevent function inlining or other
6320 aggressive transformations, so the value returned may not be that of the
6321 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6322
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6323</div>
6324
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6325<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6326<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6327 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6328</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6329
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6330<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6331
6332<h5>Syntax:</h5>
6333<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6334 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6335</pre>
6336
6337<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6338<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6339 of the function stack, for use
6340 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6341 useful for implementing language features like scoped automatic variable
6342 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6343
6344<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6345<p>This intrinsic returns a opaque pointer value that can be passed
6346 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6347 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6348 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6349 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6350 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6351 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6352
6353</div>
6354
6355<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6356<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6357 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6358</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6359
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6360<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6361
6362<h5>Syntax:</h5>
6363<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6364 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6365</pre>
6366
6367<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6368<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6369 the function stack to the state it was in when the
6370 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6371 executed. This is useful for implementing language features like scoped
6372 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6373
6374<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6375<p>See the description
6376 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6377
6378</div>
6379
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6380<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6381<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6382 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6383</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6384
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6385<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6386
6387<h5>Syntax:</h5>
6388<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6389 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]6390</pre>
6391
6392<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6393<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6394 insert a prefetch instruction if supported; otherwise, it is a noop.
6395 Prefetches have no effect on the behavior of the program but can change its
6396 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6397
6398<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6399<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6400 specifier determining if the fetch should be for a read (0) or write (1),
6401 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6402 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6403 specifies whether the prefetch is performed on the data (1) or instruction (0)
6404 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6405 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6406
6407<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6408<p>This intrinsic does not modify the behavior of the program. In particular,
6409 prefetches cannot trap and do not produce a value. On targets that support
6410 this intrinsic, the prefetch can provide hints to the processor cache for
6411 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6412
6413</div>
6414
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6415<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6416<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6417 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6418</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6419
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6420<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6421
6422<h5>Syntax:</h5>
6423<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6424 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6425</pre>
6426
6427<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6428<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6429 Counter (PC) in a region of code to simulators and other tools. The method
6430 is target specific, but it is expected that the marker will use exported
6431 symbols to transmit the PC of the marker. The marker makes no guarantees
6432 that it will remain with any specific instruction after optimizations. It is
6433 possible that the presence of a marker will inhibit optimizations. The
6434 intended use is to be inserted after optimizations to allow correlations of
6435 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6436
6437<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6438<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6439
6440<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6441<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6442 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6443
6444</div>
6445
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6446<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6447<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6448 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6449</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6450
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6451<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6452
6453<h5>Syntax:</h5>
6454<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6455 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6456</pre>
6457
6458<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6459<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6460 counter register (or similar low latency, high accuracy clocks) on those
6461 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6462 should map to RPCC. As the backing counters overflow quickly (on the order
6463 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6464
6465<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6466<p>When directly supported, reading the cycle counter should not modify any
6467 memory. Implementations are allowed to either return a application specific
6468 value or a system wide value. On backends without support, this is lowered
6469 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6470
6471</div>
6472
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6473</div>
6474
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6475<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6476<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6477 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6478</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6479
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6480<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6481
6482<p>LLVM provides intrinsics for a few important standard C library functions.
6483 These intrinsics allow source-language front-ends to pass information about
6484 the alignment of the pointer arguments to the code generator, providing
6485 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6486
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6487<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6488<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6489 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6490</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6491
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6492<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6493
6494<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6495<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]6496 integer bit width and for different address spaces. Not all targets support
6497 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6498
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6499<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6500 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]6501 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6502 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]6503 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6504</pre>
6505
6506<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6507<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6508 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6509
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6510<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6511 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6512 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6513
6514<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6515
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6516<p>The first argument is a pointer to the destination, the second is a pointer
6517 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6518 number of bytes to copy, the fourth argument is the alignment of the
6519 source and destination locations, and the fifth is a boolean indicating a
6520 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6521
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6522<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]6523 then the caller guarantees that both the source and destination pointers are
6524 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6525
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6526<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6527 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6528 The detailed access behavior is not very cleanly specified and it is unwise
6529 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6530
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6531<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6532
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6533<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6534 source location to the destination location, which are not allowed to
6535 overlap. It copies "len" bytes of memory over. If the argument is known to
6536 be aligned to some boundary, this can be specified as the fourth argument,
6537 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6538
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6539</div>
6540
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6541<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6542<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6543 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6544</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6545
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6546<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6547
6548<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6549<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]6550 width and for different address space. Not all targets support all bit
6551 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6552
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6553<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6554 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]6555 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6556 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]6557 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6558</pre>
6559
6560<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6561<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6562 source location to the destination location. It is similar to the
6563 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6564 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6565
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6566<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6567 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6568 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6569
6570<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6571
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6572<p>The first argument is a pointer to the destination, the second is a pointer
6573 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6574 number of bytes to copy, the fourth argument is the alignment of the
6575 source and destination locations, and the fifth is a boolean indicating a
6576 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6577
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6578<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]6579 then the caller guarantees that the source and destination pointers are
6580 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6581
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6582<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6583 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6584 The detailed access behavior is not very cleanly specified and it is unwise
6585 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6586
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6587<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6588
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6589<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6590 source location to the destination location, which may overlap. It copies
6591 "len" bytes of memory over. If the argument is known to be aligned to some
6592 boundary, this can be specified as the fourth argument, otherwise it should
6593 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6594
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6595</div>
6596
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6597<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6598<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6599 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6600</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6601
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6602<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6603
6604<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6605<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]6606 width and for different address spaces. However, not all targets support all
6607 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6608
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6609<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6610 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6611 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6612 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6613 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6614</pre>
6615
6616<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6617<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6618 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6619
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6620<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6621 intrinsic does not return a value and takes extra alignment/volatile
6622 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6623
6624<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6625<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]6626 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6627 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6628 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6629
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6630<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]6631 then the caller guarantees that the destination pointer is aligned to that
6632 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6633
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6634<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6635 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6636 The detailed access behavior is not very cleanly specified and it is unwise
6637 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6638
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6639<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6640<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6641 at the destination location. If the argument is known to be aligned to some
6642 boundary, this can be specified as the fourth argument, otherwise it should
6643 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6644
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6645</div>
6646
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6647<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6648<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6649 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6650</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6651
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6652<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6653
6654<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6655<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6656 floating point or vector of floating point type. Not all targets support all
6657 types however.</p>
6658
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6659<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6660 declare float @llvm.sqrt.f32(float %Val)
6661 declare double @llvm.sqrt.f64(double %Val)
6662 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6663 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6664 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6665</pre>
6666
6667<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6668<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6669 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6670 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6671 behavior for negative numbers other than -0.0 (which allows for better
6672 optimization, because there is no need to worry about errno being
6673 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]6674
6675<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6676<p>The argument and return value are floating point numbers of the same
6677 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6678
6679<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6680<p>This function returns the sqrt of the specified operand if it is a
6681 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6682
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6683</div>
6684
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6685<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6686<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6687 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6688</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6689
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6690<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6691
6692<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6693<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6694 floating point or vector of floating point type. Not all targets support all
6695 types however.</p>
6696
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6697<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6698 declare float @llvm.powi.f32(float %Val, i32 %power)
6699 declare double @llvm.powi.f64(double %Val, i32 %power)
6700 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6701 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6702 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6703</pre>
6704
6705<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6706<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6707 specified (positive or negative) power. The order of evaluation of
6708 multiplications is not defined. When a vector of floating point type is
6709 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6710
6711<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6712<p>The second argument is an integer power, and the first is a value to raise to
6713 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6714
6715<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6716<p>This function returns the first value raised to the second power with an
6717 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6718
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6719</div>
6720
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6721<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6722<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6723 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6724</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6725
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6726<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6727
6728<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6729<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6730 floating point or vector of floating point type. Not all targets support all
6731 types however.</p>
6732
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6733<pre>
6734 declare float @llvm.sin.f32(float %Val)
6735 declare double @llvm.sin.f64(double %Val)
6736 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6737 declare fp128 @llvm.sin.f128(fp128 %Val)
6738 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6739</pre>
6740
6741<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6742<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6743
6744<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6745<p>The argument and return value are floating point numbers of the same
6746 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6747
6748<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6749<p>This function returns the sine of the specified operand, returning the same
6750 values as the libm <tt>sin</tt> functions would, and handles error conditions
6751 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6752
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6753</div>
6754
6755<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6756<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6757 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6758</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6759
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6760<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6761
6762<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6763<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6764 floating point or vector of floating point type. Not all targets support all
6765 types however.</p>
6766
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6767<pre>
6768 declare float @llvm.cos.f32(float %Val)
6769 declare double @llvm.cos.f64(double %Val)
6770 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6771 declare fp128 @llvm.cos.f128(fp128 %Val)
6772 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6773</pre>
6774
6775<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6777
6778<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6779<p>The argument and return value are floating point numbers of the same
6780 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6781
6782<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6783<p>This function returns the cosine of the specified operand, returning the same
6784 values as the libm <tt>cos</tt> functions would, and handles error conditions
6785 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6786
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6787</div>
6788
6789<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6790<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6791 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6792</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6793
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6794<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6795
6796<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6797<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6798 floating point or vector of floating point type. Not all targets support all
6799 types however.</p>
6800
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6801<pre>
6802 declare float @llvm.pow.f32(float %Val, float %Power)
6803 declare double @llvm.pow.f64(double %Val, double %Power)
6804 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6805 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6806 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6807</pre>
6808
6809<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6810<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6811 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6812
6813<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6814<p>The second argument is a floating point power, and the first is a value to
6815 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6816
6817<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6818<p>This function returns the first value raised to the second power, returning
6819 the same values as the libm <tt>pow</tt> functions would, and handles error
6820 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6821
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6822</div>
6823
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6824</div>
6825
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6826<!-- _______________________________________________________________________ -->
6827<h4>
6828 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6829</h4>
6830
6831<div>
6832
6833<h5>Syntax:</h5>
6834<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6835 floating point or vector of floating point type. Not all targets support all
6836 types however.</p>
6837
6838<pre>
6839 declare float @llvm.exp.f32(float %Val)
6840 declare double @llvm.exp.f64(double %Val)
6841 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6842 declare fp128 @llvm.exp.f128(fp128 %Val)
6843 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6844</pre>
6845
6846<h5>Overview:</h5>
6847<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6848
6849<h5>Arguments:</h5>
6850<p>The argument and return value are floating point numbers of the same
6851 type.</p>
6852
6853<h5>Semantics:</h5>
6854<p>This function returns the same values as the libm <tt>exp</tt> functions
6855 would, and handles error conditions in the same way.</p>
6856
6857</div>
6858
6859<!-- _______________________________________________________________________ -->
6860<h4>
6861 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6862</h4>
6863
6864<div>
6865
6866<h5>Syntax:</h5>
6867<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6868 floating point or vector of floating point type. Not all targets support all
6869 types however.</p>
6870
6871<pre>
6872 declare float @llvm.log.f32(float %Val)
6873 declare double @llvm.log.f64(double %Val)
6874 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6875 declare fp128 @llvm.log.f128(fp128 %Val)
6876 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6877</pre>
6878
6879<h5>Overview:</h5>
6880<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6881
6882<h5>Arguments:</h5>
6883<p>The argument and return value are floating point numbers of the same
6884 type.</p>
6885
6886<h5>Semantics:</h5>
6887<p>This function returns the same values as the libm <tt>log</tt> functions
6888 would, and handles error conditions in the same way.</p>
6889
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6890<h4>
6891 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6892</h4>
6893
6894<div>
6895
6896<h5>Syntax:</h5>
6897<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6898 floating point or vector of floating point type. Not all targets support all
6899 types however.</p>
6900
6901<pre>
6902 declare float @llvm.fma.f32(float %a, float %b, float %c)
6903 declare double @llvm.fma.f64(double %a, double %b, double %c)
6904 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6905 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6906 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6907</pre>
6908
6909<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]6910<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6911 operation.</p>
6912
6913<h5>Arguments:</h5>
6914<p>The argument and return value are floating point numbers of the same
6915 type.</p>
6916
6917<h5>Semantics:</h5>
6918<p>This function returns the same values as the libm <tt>fma</tt> functions
6919 would.</p>
6920
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6921</div>
6922
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6923<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6924<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6925 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6926</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6927
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6928<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6929
6930<p>LLVM provides intrinsics for a few important bit manipulation operations.
6931 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6932
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6933<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6934<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6935 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6936</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6937
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6938<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6939
6940<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6941<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6942 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6943
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6944<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6945 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6946 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6947 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6948</pre>
6949
6950<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6951<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6952 values with an even number of bytes (positive multiple of 16 bits). These
6953 are useful for performing operations on data that is not in the target's
6954 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6955
6956<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6957<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6958 and low byte of the input i16 swapped. Similarly,
6959 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6960 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6961 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6962 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6963 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6964 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6965
6966</div>
6967
6968<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6969<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6970 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6971</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6972
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6973<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6974
6975<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6976<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]6977 width, or on any vector with integer elements. Not all targets support all
6978 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6979
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6980<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6981 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6982 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6983 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6984 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6985 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6986 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]6987</pre>
6988
6989<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6990<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6991 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6992
6993<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6994<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]6995 integer type, or a vector with integer elements.
6996 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6997
6998<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6999<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7000 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7001
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7002</div>
7003
7004<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7005<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7006 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7007</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7008
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7009<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7010
7011<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7012<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]7013 integer bit width, or any vector whose elements are integers. Not all
7014 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7015
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7016<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7017 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7018 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7019 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7020 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7021 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7022 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]7023</pre>
7024
7025<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7026<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7027 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7028
7029<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7030<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]7031 integer type, or any vector type with integer element type.
7032 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7033
7034<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7035<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7036 zeros in a variable, or within each element of the vector if the operation
7037 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]7038 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7039
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7040</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]7041
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7042<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7043<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7044 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7045</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7046
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7047<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7048
7049<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7050<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]7051 integer bit width, or any vector of integer elements. Not all targets
7052 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7053
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7054<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7055 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7056 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7057 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7058 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7059 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7060 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]7061</pre>
7062
7063<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7064<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7065 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7066
7067<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7068<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]7069 integer type, or a vectory with integer element type.. The return type
7070 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7071
7072<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7073<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7074 zeros in a variable, or within each element of a vector.
7075 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7076 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7077
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7078</div>
7079
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7080</div>
7081
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7082<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7083<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7084 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7085</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7086
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7087<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7088
7089<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7090
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7091<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7092<h4>
7093 <a name="int_sadd_overflow">
7094 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7095 </a>
7096</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7097
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7098<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7099
7100<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7101<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]7102 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7103
7104<pre>
7105 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7106 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7107 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7108</pre>
7109
7110<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7111<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7112 a signed addition of the two arguments, and indicate whether an overflow
7113 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7114
7115<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7116<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]7117 be of integer types of any bit width, but they must have the same bit
7118 width. The second element of the result structure must be of
7119 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7120 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7121
7122<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7123<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7124 a signed addition of the two variables. They return a structure &mdash; the
7125 first element of which is the signed summation, and the second element of
7126 which is a bit specifying if the signed summation resulted in an
7127 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7128
7129<h5>Examples:</h5>
7130<pre>
7131 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7132 %sum = extractvalue {i32, i1} %res, 0
7133 %obit = extractvalue {i32, i1} %res, 1
7134 br i1 %obit, label %overflow, label %normal
7135</pre>
7136
7137</div>
7138
7139<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7140<h4>
7141 <a name="int_uadd_overflow">
7142 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7143 </a>
7144</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7145
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7146<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7147
7148<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7149<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]7150 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7151
7152<pre>
7153 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7154 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7155 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7156</pre>
7157
7158<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7159<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7160 an unsigned addition of the two arguments, and indicate whether a carry
7161 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7162
7163<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7164<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]7165 be of integer types of any bit width, but they must have the same bit
7166 width. The second element of the result structure must be of
7167 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7168 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7169
7170<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7171<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7172 an unsigned addition of the two arguments. They return a structure &mdash;
7173 the first element of which is the sum, and the second element of which is a
7174 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7175
7176<h5>Examples:</h5>
7177<pre>
7178 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7179 %sum = extractvalue {i32, i1} %res, 0
7180 %obit = extractvalue {i32, i1} %res, 1
7181 br i1 %obit, label %carry, label %normal
7182</pre>
7183
7184</div>
7185
7186<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7187<h4>
7188 <a name="int_ssub_overflow">
7189 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7190 </a>
7191</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7192
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7193<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7194
7195<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7196<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]7197 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7198
7199<pre>
7200 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7201 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7202 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7203</pre>
7204
7205<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7206<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7207 a signed subtraction of the two arguments, and indicate whether an overflow
7208 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7209
7210<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7211<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]7212 be of integer types of any bit width, but they must have the same bit
7213 width. The second element of the result structure must be of
7214 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7215 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7216
7217<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7218<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7219 a signed subtraction of the two arguments. They return a structure &mdash;
7220 the first element of which is the subtraction, and the second element of
7221 which is a bit specifying if the signed subtraction resulted in an
7222 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7223
7224<h5>Examples:</h5>
7225<pre>
7226 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7227 %sum = extractvalue {i32, i1} %res, 0
7228 %obit = extractvalue {i32, i1} %res, 1
7229 br i1 %obit, label %overflow, label %normal
7230</pre>
7231
7232</div>
7233
7234<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7235<h4>
7236 <a name="int_usub_overflow">
7237 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7238 </a>
7239</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7240
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7241<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7242
7243<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7244<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]7245 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7246
7247<pre>
7248 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7249 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7250 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7251</pre>
7252
7253<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7254<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7255 an unsigned subtraction of the two arguments, and indicate whether an
7256 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7257
7258<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7259<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]7260 be of integer types of any bit width, but they must have the same bit
7261 width. The second element of the result structure must be of
7262 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7263 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7264
7265<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7266<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7267 an unsigned subtraction of the two arguments. They return a structure &mdash;
7268 the first element of which is the subtraction, and the second element of
7269 which is a bit specifying if the unsigned subtraction resulted in an
7270 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7271
7272<h5>Examples:</h5>
7273<pre>
7274 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7275 %sum = extractvalue {i32, i1} %res, 0
7276 %obit = extractvalue {i32, i1} %res, 1
7277 br i1 %obit, label %overflow, label %normal
7278</pre>
7279
7280</div>
7281
7282<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7283<h4>
7284 <a name="int_smul_overflow">
7285 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7286 </a>
7287</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7288
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7289<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7290
7291<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7292<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]7293 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7294
7295<pre>
7296 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7297 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7298 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7299</pre>
7300
7301<h5>Overview:</h5>
7302
7303<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7304 a signed multiplication of the two arguments, and indicate whether an
7305 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7306
7307<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7308<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]7309 be of integer types of any bit width, but they must have the same bit
7310 width. The second element of the result structure must be of
7311 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7312 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7313
7314<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7315<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7316 a signed multiplication of the two arguments. They return a structure &mdash;
7317 the first element of which is the multiplication, and the second element of
7318 which is a bit specifying if the signed multiplication resulted in an
7319 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7320
7321<h5>Examples:</h5>
7322<pre>
7323 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7324 %sum = extractvalue {i32, i1} %res, 0
7325 %obit = extractvalue {i32, i1} %res, 1
7326 br i1 %obit, label %overflow, label %normal
7327</pre>
7328
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7329</div>
7330
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7331<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7332<h4>
7333 <a name="int_umul_overflow">
7334 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7335 </a>
7336</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7337
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7338<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7339
7340<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7341<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]7342 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7343
7344<pre>
7345 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7346 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7347 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7348</pre>
7349
7350<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7351<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7352 a unsigned multiplication of the two arguments, and indicate whether an
7353 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7354
7355<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7356<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]7357 be of integer types of any bit width, but they must have the same bit
7358 width. The second element of the result structure must be of
7359 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7360 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7361
7362<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7363<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7364 an unsigned multiplication of the two arguments. They return a structure
7365 &mdash; the first element of which is the multiplication, and the second
7366 element of which is a bit specifying if the unsigned multiplication resulted
7367 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7368
7369<h5>Examples:</h5>
7370<pre>
7371 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7372 %sum = extractvalue {i32, i1} %res, 0
7373 %obit = extractvalue {i32, i1} %res, 1
7374 br i1 %obit, label %overflow, label %normal
7375</pre>
7376
7377</div>
7378
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7379</div>
7380
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7381<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7382<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7383 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7384</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7385
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7386<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7387
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7388<p>Half precision floating point is a storage-only format. This means that it is
7389 a dense encoding (in memory) but does not support computation in the
7390 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7391
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7392<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7393 value as an i16, then convert it to float with <a
7394 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7395 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7396 double etc). To store the value back to memory, it is first converted to
7397 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7398 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7399 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7400
7401<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7402<h4>
7403 <a name="int_convert_to_fp16">
7404 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7405 </a>
7406</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7407
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7408<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7409
7410<h5>Syntax:</h5>
7411<pre>
7412 declare i16 @llvm.convert.to.fp16(f32 %a)
7413</pre>
7414
7415<h5>Overview:</h5>
7416<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7417 a conversion from single precision floating point format to half precision
7418 floating point format.</p>
7419
7420<h5>Arguments:</h5>
7421<p>The intrinsic function contains single argument - the value to be
7422 converted.</p>
7423
7424<h5>Semantics:</h5>
7425<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7426 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7427 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7428 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7429
7430<h5>Examples:</h5>
7431<pre>
7432 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7433 store i16 %res, i16* @x, align 2
7434</pre>
7435
7436</div>
7437
7438<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7439<h4>
7440 <a name="int_convert_from_fp16">
7441 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7442 </a>
7443</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7444
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7445<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7446
7447<h5>Syntax:</h5>
7448<pre>
7449 declare f32 @llvm.convert.from.fp16(i16 %a)
7450</pre>
7451
7452<h5>Overview:</h5>
7453<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7454 a conversion from half precision floating point format to single precision
7455 floating point format.</p>
7456
7457<h5>Arguments:</h5>
7458<p>The intrinsic function contains single argument - the value to be
7459 converted.</p>
7460
7461<h5>Semantics:</h5>
7462<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7463 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7464 precision floating point format. The input half-float value is represented by
7465 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7466
7467<h5>Examples:</h5>
7468<pre>
7469 %a = load i16* @x, align 2
7470 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7471</pre>
7472
7473</div>
7474
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7475</div>
7476
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7477<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7478<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7479 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7480</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7481
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7482<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7483
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7484<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7485 prefix), are described in
7486 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7487 Level Debugging</a> document.</p>
7488
7489</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7490
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7491<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7492<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7493 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7494</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7495
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7496<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7497
7498<p>The LLVM exception handling intrinsics (which all start with
7499 <tt>llvm.eh.</tt> prefix), are described in
7500 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7501 Handling</a> document.</p>
7502
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7503</div>
7504
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7505<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7506<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7507 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7508</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7509
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7510<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7511
7512<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7513 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7514 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7515 function pointer lacking the nest parameter - the caller does not need to
7516 provide a value for it. Instead, the value to use is stored in advance in a
7517 "trampoline", a block of memory usually allocated on the stack, which also
7518 contains code to splice the nest value into the argument list. This is used
7519 to implement the GCC nested function address extension.</p>
7520
7521<p>For example, if the function is
7522 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7523 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7524 follows:</p>
7525
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7526<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7527 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7528 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7529 %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]7530 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7531</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7532
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7533<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7534 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7535
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7536<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7537<h4>
7538 <a name="int_it">
7539 '<tt>llvm.init.trampoline</tt>' Intrinsic
7540 </a>
7541</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7542
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7543<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7544
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7545<h5>Syntax:</h5>
7546<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7547 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]7548</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7549
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7550<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7551<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7552 function pointer suitable for executing it.</p>
7553
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7554<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7555<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7556 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7557 sufficiently aligned block of memory; this memory is written to by the
7558 intrinsic. Note that the size and the alignment are target-specific - LLVM
7559 currently provides no portable way of determining them, so a front-end that
7560 generates this intrinsic needs to have some target-specific knowledge.
7561 The <tt>func</tt> argument must hold a function bitcast to
7562 an <tt>i8*</tt>.</p>
7563
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7564<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7565<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7566 dependent code, turning it into a function. A pointer to this function is
7567 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7568 function pointer type</a> before being called. The new function's signature
7569 is the same as that of <tt>func</tt> with any arguments marked with
7570 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7571 is allowed, and it must be of pointer type. Calling the new function is
7572 equivalent to calling <tt>func</tt> with the same argument list, but
7573 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7574 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7575 by <tt>tramp</tt> is modified, then the effect of any later call to the
7576 returned function pointer is undefined.</p>
7577
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7578</div>
7579
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7580</div>
7581
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7582<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7583<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7584 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7585</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7586
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7587<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7588
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7589<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7590 hardware constructs for atomic operations and memory synchronization. This
7591 provides an interface to the hardware, not an interface to the programmer. It
7592 is aimed at a low enough level to allow any programming models or APIs
7593 (Application Programming Interfaces) which need atomic behaviors to map
7594 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7595 hardware provides a "universal IR" for source languages, it also provides a
7596 starting point for developing a "universal" atomic operation and
7597 synchronization IR.</p>
7598
7599<p>These do <em>not</em> form an API such as high-level threading libraries,
7600 software transaction memory systems, atomic primitives, and intrinsic
7601 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7602 application libraries. The hardware interface provided by LLVM should allow
7603 a clean implementation of all of these APIs and parallel programming models.
7604 No one model or paradigm should be selected above others unless the hardware
7605 itself ubiquitously does so.</p>
7606
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7607<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7608<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7609 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7610</h4>
7611
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7612<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7613<h5>Syntax:</h5>
7614<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7615 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]7616</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7617
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7618<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7619<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7620 specific pairs of memory access types.</p>
7621
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7622<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7623<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7624 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7625 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7626 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7627
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7628<ul>
7629 <li><tt>ll</tt>: load-load barrier</li>
7630 <li><tt>ls</tt>: load-store barrier</li>
7631 <li><tt>sl</tt>: store-load barrier</li>
7632 <li><tt>ss</tt>: store-store barrier</li>
7633 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7634</ul>
7635
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7636<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7637<p>This intrinsic causes the system to enforce some ordering constraints upon
7638 the loads and stores of the program. This barrier does not
7639 indicate <em>when</em> any events will occur, it only enforces
7640 an <em>order</em> in which they occur. For any of the specified pairs of load
7641 and store operations (f.ex. load-load, or store-load), all of the first
7642 operations preceding the barrier will complete before any of the second
7643 operations succeeding the barrier begin. Specifically the semantics for each
7644 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7645
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7646<ul>
7647 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7648 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7649 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7650 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7651 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7652 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7653 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7654 load after the barrier begins.</li>
7655</ul>
7656
7657<p>These semantics are applied with a logical "and" behavior when more than one
7658 is enabled in a single memory barrier intrinsic.</p>
7659
7660<p>Backends may implement stronger barriers than those requested when they do
7661 not support as fine grained a barrier as requested. Some architectures do
7662 not need all types of barriers and on such architectures, these become
7663 noops.</p>
7664
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7665<h5>Example:</h5>
7666<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7667%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7668%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7669 store i32 4, %ptr
7670
7671%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7672 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]7673 <i>; guarantee the above finishes</i>
7674 store i32 8, %ptr <i>; before this begins</i>
7675</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7676
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7677</div>
7678
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7679<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7680<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7681 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7682</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7683
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7684<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7685
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7686<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7687<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7688 any integer bit width and for different address spaces. Not all targets
7689 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7690
7691<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7692 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7693 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7694 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7695 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]7696</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7697
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7698<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7699<p>This loads a value in memory and compares it to a given value. If they are
7700 equal, it stores a new value into the memory.</p>
7701
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7702<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7703<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7704 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7705 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7706 this integer type. While any bit width integer may be used, targets may only
7707 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7708
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7709<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7710<p>This entire intrinsic must be executed atomically. It first loads the value
7711 in memory pointed to by <tt>ptr</tt> and compares it with the
7712 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7713 memory. The loaded value is yielded in all cases. This provides the
7714 equivalent of an atomic compare-and-swap operation within the SSA
7715 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7716
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7717<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7718<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7719%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7720%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7721 store i32 4, %ptr
7722
7723%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7724%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7725 <i>; yields {i32}:result1 = 4</i>
7726%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7727%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7728
7729%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7730%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7731 <i>; yields {i32}:result2 = 8</i>
7732%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7733
7734%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7735</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7736
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7737</div>
7738
7739<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7740<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7741 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7742</h4>
7743
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7744<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7745<h5>Syntax:</h5>
7746
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7747<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7748 integer bit width. Not all targets support all bit widths however.</p>
7749
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7750<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7751 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7752 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7753 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7754 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]7755</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7756
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7757<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7758<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7759 the value from memory. It then stores the value in <tt>val</tt> in the memory
7760 at <tt>ptr</tt>.</p>
7761
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7762<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7763<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7764 the <tt>val</tt> argument and the result must be integers of the same bit
7765 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7766 integer type. The targets may only lower integer representations they
7767 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7768
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7769<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7770<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7771 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7772 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7773
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7774<h5>Examples:</h5>
7775<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7776%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7777%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7778 store i32 4, %ptr
7779
7780%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7781%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7782 <i>; yields {i32}:result1 = 4</i>
7783%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7784%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7785
7786%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7787%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7788 <i>; yields {i32}:result2 = 8</i>
7789
7790%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7791%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7792</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7793
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7794</div>
7795
7796<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7797<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7798 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7799</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7800
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7801<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7802
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7803<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7804<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7805 any integer bit width. Not all targets support all bit widths however.</p>
7806
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7807<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7808 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7809 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7810 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7811 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]7812</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7813
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7814<h5>Overview:</h5>
7815<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7816 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7817
7818<h5>Arguments:</h5>
7819<p>The intrinsic takes two arguments, the first a pointer to an integer value
7820 and the second an integer value. The result is also an integer value. These
7821 integer types can have any bit width, but they must all have the same bit
7822 width. The targets may only lower integer representations they support.</p>
7823
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7824<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7825<p>This intrinsic does a series of operations atomically. It first loads the
7826 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7827 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]7828
7829<h5>Examples:</h5>
7830<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7831%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7832%ptr = bitcast i8* %mallocP to i32*
7833 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7834%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7835 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7836%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7837 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7838%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7839 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7840%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7841</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7842
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7843</div>
7844
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7845<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7846<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7847 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7848</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7849
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7850<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7851
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7852<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7853<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7854 any integer bit width and for different address spaces. Not all targets
7855 support all bit widths however.</p>
7856
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7857<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7858 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7859 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7860 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7861 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]7862</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7863
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7864<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7865<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7866 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7867
7868<h5>Arguments:</h5>
7869<p>The intrinsic takes two arguments, the first a pointer to an integer value
7870 and the second an integer value. The result is also an integer value. These
7871 integer types can have any bit width, but they must all have the same bit
7872 width. The targets may only lower integer representations they support.</p>
7873
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7874<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7875<p>This intrinsic does a series of operations atomically. It first loads the
7876 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7877 result to <tt>ptr</tt>. It yields the original value stored
7878 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7879
7880<h5>Examples:</h5>
7881<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7882%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7883%ptr = bitcast i8* %mallocP to i32*
7884 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7885%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7886 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7887%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7888 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7889%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7890 <i>; yields {i32}:result3 = 2</i>
7891%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7892</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7893
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7894</div>
7895
7896<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7897<h4>
7898 <a name="int_atomic_load_and">
7899 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7900 </a>
7901 <br>
7902 <a name="int_atomic_load_nand">
7903 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7904 </a>
7905 <br>
7906 <a name="int_atomic_load_or">
7907 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7908 </a>
7909 <br>
7910 <a name="int_atomic_load_xor">
7911 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7912 </a>
7913</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7914
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7915<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7916
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7917<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7918<p>These are overloaded intrinsics. You can
7919 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7920 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7921 bit width and for different address spaces. Not all targets support all bit
7922 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7923
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7924<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7925 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7926 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7927 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7928 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]7929</pre>
7930
7931<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7932 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7933 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7934 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7935 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]7936</pre>
7937
7938<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7939 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7940 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7941 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7942 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]7943</pre>
7944
7945<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7946 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7947 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7948 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7949 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]7950</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7951
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7952<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7953<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7954 the value stored in memory at <tt>ptr</tt>. It yields the original value
7955 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7956
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7957<h5>Arguments:</h5>
7958<p>These intrinsics take two arguments, the first a pointer to an integer value
7959 and the second an integer value. The result is also an integer value. These
7960 integer types can have any bit width, but they must all have the same bit
7961 width. The targets may only lower integer representations they support.</p>
7962
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7963<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7964<p>These intrinsics does a series of operations atomically. They first load the
7965 value stored at <tt>ptr</tt>. They then do the bitwise
7966 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7967 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7968
7969<h5>Examples:</h5>
7970<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7971%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7972%ptr = bitcast i8* %mallocP to i32*
7973 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7974%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7975 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7976%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7977 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7978%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7979 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7980%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7981 <i>; yields {i32}:result3 = FF</i>
7982%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7983</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7984
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7985</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7986
7987<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7988<h4>
7989 <a name="int_atomic_load_max">
7990 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7991 </a>
7992 <br>
7993 <a name="int_atomic_load_min">
7994 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7995 </a>
7996 <br>
7997 <a name="int_atomic_load_umax">
7998 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7999 </a>
8000 <br>
8001 <a name="int_atomic_load_umin">
8002 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8003 </a>
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
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8008<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8009<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8010 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8011 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8012 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8013
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8014<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8015 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8016 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8017 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8018 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]8019</pre>
8020
8021<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8022 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8023 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8024 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8025 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]8026</pre>
8027
8028<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8029 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8030 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8031 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8032 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]8033</pre>
8034
8035<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8036 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8037 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8038 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8039 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]8040</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8041
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8042<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8043<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8044 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8045 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8046
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8047<h5>Arguments:</h5>
8048<p>These intrinsics take two arguments, the first a pointer to an integer value
8049 and the second an integer value. The result is also an integer value. These
8050 integer types can have any bit width, but they must all have the same bit
8051 width. The targets may only lower integer representations they support.</p>
8052
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8053<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8054<p>These intrinsics does a series of operations atomically. They first load the
8055 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8056 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8057 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8058
8059<h5>Examples:</h5>
8060<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]8061%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8062%ptr = bitcast i8* %mallocP to i32*
8063 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8064%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8065 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8066%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8067 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8068%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8069 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8070%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8071 <i>; yields {i32}:result3 = 8</i>
8072%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8073</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8074
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8075</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8076
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8077</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8078
8079<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8080<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8081 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8082</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8083
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8084<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8085
8086<p>This class of intrinsics exists to information about the lifetime of memory
8087 objects and ranges where variables are immutable.</p>
8088
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8089<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8090<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8091 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8092</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8093
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8094<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8095
8096<h5>Syntax:</h5>
8097<pre>
8098 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8099</pre>
8100
8101<h5>Overview:</h5>
8102<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8103 object's lifetime.</p>
8104
8105<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8106<p>The first argument is a constant integer representing the size of the
8107 object, or -1 if it is variable sized. The second argument is a pointer to
8108 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8109
8110<h5>Semantics:</h5>
8111<p>This intrinsic indicates that before this point in the code, the value of the
8112 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]8113 never be used and has an undefined value. A load from the pointer that
8114 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8115 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8116
8117</div>
8118
8119<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8120<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8121 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8122</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8123
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8124<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8125
8126<h5>Syntax:</h5>
8127<pre>
8128 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8129</pre>
8130
8131<h5>Overview:</h5>
8132<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8133 object's lifetime.</p>
8134
8135<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8136<p>The first argument is a constant integer representing the size of the
8137 object, or -1 if it is variable sized. The second argument is a pointer to
8138 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8139
8140<h5>Semantics:</h5>
8141<p>This intrinsic indicates that after this point in the code, the value of the
8142 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8143 never be used and has an undefined value. Any stores into the memory object
8144 following this intrinsic may be removed as dead.
8145
8146</div>
8147
8148<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8149<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8150 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8151</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8152
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8153<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8154
8155<h5>Syntax:</h5>
8156<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]8157 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8158</pre>
8159
8160<h5>Overview:</h5>
8161<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8162 a memory object will not change.</p>
8163
8164<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8165<p>The first argument is a constant integer representing the size of the
8166 object, or -1 if it is variable sized. The second argument is a pointer to
8167 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8168
8169<h5>Semantics:</h5>
8170<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8171 the return value, the referenced memory location is constant and
8172 unchanging.</p>
8173
8174</div>
8175
8176<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8177<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8178 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8179</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8180
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8181<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8182
8183<h5>Syntax:</h5>
8184<pre>
8185 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8186</pre>
8187
8188<h5>Overview:</h5>
8189<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8190 a memory object are mutable.</p>
8191
8192<h5>Arguments:</h5>
8193<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8194 The second argument is a constant integer representing the size of the
8195 object, or -1 if it is variable sized and the third argument is a pointer
8196 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8197
8198<h5>Semantics:</h5>
8199<p>This intrinsic indicates that the memory is mutable again.</p>
8200
8201</div>
8202
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8203</div>
8204
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8205<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8206<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8207 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8208</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8209
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8210<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8211
8212<p>This class of intrinsics is designed to be generic and has no specific
8213 purpose.</p>
8214
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8215<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8216<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8217 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8218</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8219
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8220<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8221
8222<h5>Syntax:</h5>
8223<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8224 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]8225</pre>
8226
8227<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8228<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8229
8230<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8231<p>The first argument is a pointer to a value, the second is a pointer to a
8232 global string, the third is a pointer to a global string which is the source
8233 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8234
8235<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8236<p>This intrinsic allows annotation of local variables with arbitrary strings.
8237 This can be useful for special purpose optimizations that want to look for
8238 these annotations. These have no other defined use, they are ignored by code
8239 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8240
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8241</div>
8242
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8243<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8244<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]8245 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8246</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8247
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8248<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8249
8250<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8251<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8252 any integer bit width.</p>
8253
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8254<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8255 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8256 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8257 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8258 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8259 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]8260</pre>
8261
8262<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8263<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8264
8265<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8266<p>The first argument is an integer value (result of some expression), the
8267 second is a pointer to a global string, the third is a pointer to a global
8268 string which is the source file name, and the last argument is the line
8269 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8270
8271<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8272<p>This intrinsic allows annotations to be put on arbitrary expressions with
8273 arbitrary strings. This can be useful for special purpose optimizations that
8274 want to look for these annotations. These have no other defined use, they
8275 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8276
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8277</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8278
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8279<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8280<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8281 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8282</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8283
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8284<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8285
8286<h5>Syntax:</h5>
8287<pre>
8288 declare void @llvm.trap()
8289</pre>
8290
8291<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8292<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8293
8294<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8295<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8296
8297<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8298<p>This intrinsics is lowered to the target dependent trap instruction. If the
8299 target does not have a trap instruction, this intrinsic will be lowered to
8300 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8301
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8302</div>
8303
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8304<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8305<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]8306 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8307</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8308
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8309<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8310
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8311<h5>Syntax:</h5>
8312<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8313 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8314</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8315
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8316<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8317<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8318 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8319 ensure that it is placed on the stack before local variables.</p>
8320
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8321<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8322<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8323 arguments. The first argument is the value loaded from the stack
8324 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8325 that has enough space to hold the value of the guard.</p>
8326
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8327<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8328<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8329 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8330 stack. This is to ensure that if a local variable on the stack is
8331 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8332 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8333 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8334 function.</p>
8335
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8336</div>
8337
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8338<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8339<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8340 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8341</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8342
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8343<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8344
8345<h5>Syntax:</h5>
8346<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8347 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8348 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8349</pre>
8350
8351<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8352<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8353 the optimizers to determine at compile time whether a) an operation (like
8354 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8355 runtime check for overflow isn't necessary. An object in this context means
8356 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8357
8358<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8359<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8360 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8361 is a boolean 0 or 1. This argument determines whether you want the
8362 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]8363 1, variables are not allowed.</p>
8364
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8365<h5>Semantics:</h5>
8366<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8367 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8368 depending on the <tt>type</tt> argument, if the size cannot be determined at
8369 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8370
8371</div>
8372
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8373</div>
8374
8375</div>
8376
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8377<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8378<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8379<address>
8380 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8381 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8382 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8383 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]8384
8385 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8386 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8387 Last modified: $Date$
8388</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8389
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8390</body>
8391</html>