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gerrit-public.fairphone.software / toolchain / llvm-project / 49bfb12c4608f5d6afa3ed83334a5cb8e1d7783c / . / 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>
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]127 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]128 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]129 </ol>
130 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]131 <li><a href="#binaryops">Binary Operations</a>
132 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]137 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]138 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]139 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
140 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
141 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]142 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
143 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
144 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]145 </ol>
146 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]147 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
148 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]149 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
150 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
151 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]154 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]157 <li><a href="#vectorops">Vector Operations</a>
158 <ol>
159 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
160 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
161 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]162 </ol>
163 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]164 <li><a href="#aggregateops">Aggregate Operations</a>
165 <ol>
166 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
167 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
168 </ol>
169 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]170 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]171 <ol>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]172 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
173 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
174 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
175 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
176 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
177 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]178 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]179 </ol>
180 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]181 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]182 <ol>
183 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
184 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
186 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
187 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]188 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
189 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
190 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
191 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]192 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
193 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]194 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]195 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]196 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]197 <li><a href="#otherops">Other Operations</a>
198 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]199 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
200 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]201 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]202 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]203 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]204 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]205 <li><a href="#i_landingpad">'<tt>landingpad</tt>' Instruction</a></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 Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]208 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]209 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]210 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]211 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]212 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
213 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]214 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
215 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
216 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]217 </ol>
218 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]219 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
220 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]221 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
222 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
223 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]224 </ol>
225 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]226 <li><a href="#int_codegen">Code Generator Intrinsics</a>
227 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]228 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
229 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
230 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
231 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
232 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
233 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]234 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]235 </ol>
236 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]237 <li><a href="#int_libc">Standard C Library Intrinsics</a>
238 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]239 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
243 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]244 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
245 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
246 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]247 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
248 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]249 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]250 </ol>
251 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]252 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]253 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]254 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]255 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
256 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
257 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]258 </ol>
259 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]260 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
261 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]262 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
263 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
264 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
265 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
266 <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]267 <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]268 </ol>
269 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]270 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
271 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]272 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
273 <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]274 </ol>
275 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]276 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]277 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]278 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]279 <ol>
280 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]281 </ol>
282 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]283 <li><a href="#int_atomics">Atomic intrinsics</a>
284 <ol>
285 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
286 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
287 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
288 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
289 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
290 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
291 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
292 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
293 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
294 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
295 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
296 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
297 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
298 </ol>
299 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]300 <li><a href="#int_memorymarkers">Memory Use Markers</a>
301 <ol>
302 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
303 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
304 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
305 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
306 </ol>
307 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]308 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]309 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]310 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]311 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]312 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]313 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]314 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]315 '<tt>llvm.trap</tt>' Intrinsic</a></li>
316 <li><a href="#int_stackprotector">
317 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]318 <li><a href="#int_objectsize">
319 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]320 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]321 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]322 </ol>
323 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]324</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]325
326<div class="doc_author">
327 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
328 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]329</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]330
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]331<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]332<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]333<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]334
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]335<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]336
337<p>This document is a reference manual for the LLVM assembly language. LLVM is
338 a Static Single Assignment (SSA) based representation that provides type
339 safety, low-level operations, flexibility, and the capability of representing
340 'all' high-level languages cleanly. It is the common code representation
341 used throughout all phases of the LLVM compilation strategy.</p>
342
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]343</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]344
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]345<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]346<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]347<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]348
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]349<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]350
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]351<p>The LLVM code representation is designed to be used in three different forms:
352 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
353 for fast loading by a Just-In-Time compiler), and as a human readable
354 assembly language representation. This allows LLVM to provide a powerful
355 intermediate representation for efficient compiler transformations and
356 analysis, while providing a natural means to debug and visualize the
357 transformations. The three different forms of LLVM are all equivalent. This
358 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]359
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]360<p>The LLVM representation aims to be light-weight and low-level while being
361 expressive, typed, and extensible at the same time. It aims to be a
362 "universal IR" of sorts, by being at a low enough level that high-level ideas
363 may be cleanly mapped to it (similar to how microprocessors are "universal
364 IR's", allowing many source languages to be mapped to them). By providing
365 type information, LLVM can be used as the target of optimizations: for
366 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]367 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]368 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]369
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]370<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]371<h4>
372 <a name="wellformed">Well-Formedness</a>
373</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]374
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]375<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]376
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]377<p>It is important to note that this document describes 'well formed' LLVM
378 assembly language. There is a difference between what the parser accepts and
379 what is considered 'well formed'. For example, the following instruction is
380 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]381
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]382<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]383%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]384</pre>
385
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]386<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
387 LLVM infrastructure provides a verification pass that may be used to verify
388 that an LLVM module is well formed. This pass is automatically run by the
389 parser after parsing input assembly and by the optimizer before it outputs
390 bitcode. The violations pointed out by the verifier pass indicate bugs in
391 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]392
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]393</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]394
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]395</div>
396
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]397<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]398
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]399<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]400<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]401<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]402
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]403<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]404
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]405<p>LLVM identifiers come in two basic types: global and local. Global
406 identifiers (functions, global variables) begin with the <tt>'@'</tt>
407 character. Local identifiers (register names, types) begin with
408 the <tt>'%'</tt> character. Additionally, there are three different formats
409 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]410
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]411<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]412 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]413 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
414 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
415 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
416 other characters in their names can be surrounded with quotes. Special
417 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
418 ASCII code for the character in hexadecimal. In this way, any character
419 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]420
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]421 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]422 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]423
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]424 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]425 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]426</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]427
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]428<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]429 don't need to worry about name clashes with reserved words, and the set of
430 reserved words may be expanded in the future without penalty. Additionally,
431 unnamed identifiers allow a compiler to quickly come up with a temporary
432 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]433
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]434<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]435 languages. There are keywords for different opcodes
436 ('<tt><a href="#i_add">add</a></tt>',
437 '<tt><a href="#i_bitcast">bitcast</a></tt>',
438 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
439 ('<tt><a href="#t_void">void</a></tt>',
440 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
441 reserved words cannot conflict with variable names, because none of them
442 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]443
444<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]445 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]447<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]449<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]450%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]451</pre>
452
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]453<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]454
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]455<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]456%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]457</pre>
458
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]459<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]460
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]461<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]462%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
463%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]464%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465</pre>
466
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]467<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
468 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]469
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]470<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]471 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]472 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]473
474 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]475 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]476
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]477 <li>Unnamed temporaries are numbered sequentially</li>
478</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]479
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]480<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]481 demonstrating instructions, we will follow an instruction with a comment that
482 defines the type and name of value produced. Comments are shown in italic
483 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]484
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]485</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]486
487<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]488<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]490<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]492<h3>
493 <a name="modulestructure">Module Structure</a>
494</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]495
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]496<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]498<p>LLVM programs are composed of "Module"s, each of which is a translation unit
499 of the input programs. Each module consists of functions, global variables,
500 and symbol table entries. Modules may be combined together with the LLVM
501 linker, which merges function (and global variable) definitions, resolves
502 forward declarations, and merges symbol table entries. Here is an example of
503 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]504
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]505<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]506<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]507<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]508
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]509<i>; External declaration of the puts function</i>&nbsp;
510<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]511
512<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]513define i32 @main() { <i>; i32()* </i>&nbsp;
514 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
515 %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]516
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]517 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
518 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
519 <a href="#i_ret">ret</a> i32 0&nbsp;
520}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]521
522<i>; Named metadata</i>
523!1 = metadata !{i32 41}
524!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]525</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]527<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]528 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]529 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]530 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
531 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]532
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]533<p>In general, a module is made up of a list of global values, where both
534 functions and global variables are global values. Global values are
535 represented by a pointer to a memory location (in this case, a pointer to an
536 array of char, and a pointer to a function), and have one of the
537 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]538
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]539</div>
540
541<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]542<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]543 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]544</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]545
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]546<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]547
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]548<p>All Global Variables and Functions have one of the following types of
549 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]550
551<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]552 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]553 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
554 by objects in the current module. In particular, linking code into a
555 module with an private global value may cause the private to be renamed as
556 necessary to avoid collisions. Because the symbol is private to the
557 module, all references can be updated. This doesn't show up in any symbol
558 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]559
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]560 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]561 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
562 assembler and evaluated by the linker. Unlike normal strong symbols, they
563 are removed by the linker from the final linked image (executable or
564 dynamic library).</dd>
565
566 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
567 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
568 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
569 linker. The symbols are removed by the linker from the final linked image
570 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]571
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]572 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
573 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
574 of the object is not taken. For instance, functions that had an inline
575 definition, but the compiler decided not to inline it. Note,
576 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
577 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
578 visibility. The symbols are removed by the linker from the final linked
579 image (executable or dynamic library).</dd>
580
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]582 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]583 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
584 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]585
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]586 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]587 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]588 into the object file corresponding to the LLVM module. They exist to
589 allow inlining and other optimizations to take place given knowledge of
590 the definition of the global, which is known to be somewhere outside the
591 module. Globals with <tt>available_externally</tt> linkage are allowed to
592 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
593 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]594
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]595 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]596 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]597 the same name when linkage occurs. This can be used to implement
598 some forms of inline functions, templates, or other code which must be
599 generated in each translation unit that uses it, but where the body may
600 be overridden with a more definitive definition later. Unreferenced
601 <tt>linkonce</tt> globals are allowed to be discarded. Note that
602 <tt>linkonce</tt> linkage does not actually allow the optimizer to
603 inline the body of this function into callers because it doesn't know if
604 this definition of the function is the definitive definition within the
605 program or whether it will be overridden by a stronger definition.
606 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
607 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]608
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]610 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
611 <tt>linkonce</tt> linkage, except that unreferenced globals with
612 <tt>weak</tt> linkage may not be discarded. This is used for globals that
613 are declared "weak" in C source code.</dd>
614
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]615 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]616 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
617 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
618 global scope.
619 Symbols with "<tt>common</tt>" linkage are merged in the same way as
620 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]621 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]622 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]623 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
624 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]625
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]626
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]627 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]628 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]629 pointer to array type. When two global variables with appending linkage
630 are linked together, the two global arrays are appended together. This is
631 the LLVM, typesafe, equivalent of having the system linker append together
632 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]633
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]634 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]635 <dd>The semantics of this linkage follow the ELF object file model: the symbol
636 is weak until linked, if not linked, the symbol becomes null instead of
637 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]638
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]639 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
640 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]641 <dd>Some languages allow differing globals to be merged, such as two functions
642 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]643 that only equivalent globals are ever merged (the "one definition rule"
644 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]645 and <tt>weak_odr</tt> linkage types to indicate that the global will only
646 be merged with equivalent globals. These linkage types are otherwise the
647 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]648
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]649 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]650 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]651 visible, meaning that it participates in linkage and can be used to
652 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]653</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]654
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]655<p>The next two types of linkage are targeted for Microsoft Windows platform
656 only. They are designed to support importing (exporting) symbols from (to)
657 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]658
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]659<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]660 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]661 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]662 or variable via a global pointer to a pointer that is set up by the DLL
663 exporting the symbol. On Microsoft Windows targets, the pointer name is
664 formed by combining <code>__imp_</code> and the function or variable
665 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]666
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]667 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]668 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]669 pointer to a pointer in a DLL, so that it can be referenced with the
670 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
671 name is formed by combining <code>__imp_</code> and the function or
672 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]673</dl>
674
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]675<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
676 another module defined a "<tt>.LC0</tt>" variable and was linked with this
677 one, one of the two would be renamed, preventing a collision. Since
678 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
679 declarations), they are accessible outside of the current module.</p>
680
681<p>It is illegal for a function <i>declaration</i> to have any linkage type
682 other than "externally visible", <tt>dllimport</tt>
683 or <tt>extern_weak</tt>.</p>
684
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]685<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]686 or <tt>weak_odr</tt> linkages.</p>
687
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]688</div>
689
690<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]691<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]692 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]693</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]694
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]695<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]696
697<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]698 and <a href="#i_invoke">invokes</a> can all have an optional calling
699 convention specified for the call. The calling convention of any pair of
700 dynamic caller/callee must match, or the behavior of the program is
701 undefined. The following calling conventions are supported by LLVM, and more
702 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]703
704<dl>
705 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]706 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]707 specified) matches the target C calling conventions. This calling
708 convention supports varargs function calls and tolerates some mismatch in
709 the declared prototype and implemented declaration of the function (as
710 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]711
712 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]713 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]714 (e.g. by passing things in registers). This calling convention allows the
715 target to use whatever tricks it wants to produce fast code for the
716 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]717 (Application Binary Interface).
718 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]719 when this or the GHC convention is used.</a> This calling convention
720 does not support varargs and requires the prototype of all callees to
721 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]722
723 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]724 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]725 as possible under the assumption that the call is not commonly executed.
726 As such, these calls often preserve all registers so that the call does
727 not break any live ranges in the caller side. This calling convention
728 does not support varargs and requires the prototype of all callees to
729 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]730
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]731 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
732 <dd>This calling convention has been implemented specifically for use by the
733 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
734 It passes everything in registers, going to extremes to achieve this by
735 disabling callee save registers. This calling convention should not be
736 used lightly but only for specific situations such as an alternative to
737 the <em>register pinning</em> performance technique often used when
738 implementing functional programming languages.At the moment only X86
739 supports this convention and it has the following limitations:
740 <ul>
741 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
742 floating point types are supported.</li>
743 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
744 6 floating point parameters.</li>
745 </ul>
746 This calling convention supports
747 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
748 requires both the caller and callee are using it.
749 </dd>
750
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]751 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]752 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]753 target-specific calling conventions to be used. Target specific calling
754 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]755</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]756
757<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]758 support Pascal conventions or any other well-known target-independent
759 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]760
761</div>
762
763<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]764<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]765 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]766</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]767
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]768<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]769
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]770<p>All Global Variables and Functions have one of the following visibility
771 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]772
773<dl>
774 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]775 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]776 that the declaration is visible to other modules and, in shared libraries,
777 means that the declared entity may be overridden. On Darwin, default
778 visibility means that the declaration is visible to other modules. Default
779 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]780
781 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]782 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]783 object if they are in the same shared object. Usually, hidden visibility
784 indicates that the symbol will not be placed into the dynamic symbol
785 table, so no other module (executable or shared library) can reference it
786 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]787
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]788 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]789 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]790 the dynamic symbol table, but that references within the defining module
791 will bind to the local symbol. That is, the symbol cannot be overridden by
792 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]793</dl>
794
795</div>
796
797<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]798<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]799 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]800</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]801
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]802<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]803
804<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]805 it easier to read the IR and make the IR more condensed (particularly when
806 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]807
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]808<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]809%mytype = type { %mytype*, i32 }
810</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]811
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]812<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]813 "<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]814 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]815
816<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]817 and that you can therefore specify multiple names for the same type. This
818 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
819 uses structural typing, the name is not part of the type. When printing out
820 LLVM IR, the printer will pick <em>one name</em> to render all types of a
821 particular shape. This means that if you have code where two different
822 source types end up having the same LLVM type, that the dumper will sometimes
823 print the "wrong" or unexpected type. This is an important design point and
824 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]825
826</div>
827
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]828<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]829<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]830 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]831</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]832
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]833<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]834
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]835<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]836 instead of run-time. Global variables may optionally be initialized, may
837 have an explicit section to be placed in, and may have an optional explicit
838 alignment specified. A variable may be defined as "thread_local", which
839 means that it will not be shared by threads (each thread will have a
840 separated copy of the variable). A variable may be defined as a global
841 "constant," which indicates that the contents of the variable
842 will <b>never</b> be modified (enabling better optimization, allowing the
843 global data to be placed in the read-only section of an executable, etc).
844 Note that variables that need runtime initialization cannot be marked
845 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]846
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]847<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
848 constant, even if the final definition of the global is not. This capability
849 can be used to enable slightly better optimization of the program, but
850 requires the language definition to guarantee that optimizations based on the
851 'constantness' are valid for the translation units that do not include the
852 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]853
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]854<p>As SSA values, global variables define pointer values that are in scope
855 (i.e. they dominate) all basic blocks in the program. Global variables
856 always define a pointer to their "content" type because they describe a
857 region of memory, and all memory objects in LLVM are accessed through
858 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]859
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]860<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
861 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]862 like this can be merged with other constants if they have the same
863 initializer. Note that a constant with significant address <em>can</em>
864 be merged with a <tt>unnamed_addr</tt> constant, the result being a
865 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]866
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]867<p>A global variable may be declared to reside in a target-specific numbered
868 address space. For targets that support them, address spaces may affect how
869 optimizations are performed and/or what target instructions are used to
870 access the variable. The default address space is zero. The address space
871 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]872
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]873<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]874 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]875
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]876<p>An explicit alignment may be specified for a global, which must be a power
877 of 2. If not present, or if the alignment is set to zero, the alignment of
878 the global is set by the target to whatever it feels convenient. If an
879 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]880 alignment. Targets and optimizers are not allowed to over-align the global
881 if the global has an assigned section. In this case, the extra alignment
882 could be observable: for example, code could assume that the globals are
883 densely packed in their section and try to iterate over them as an array,
884 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]885
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]886<p>For example, the following defines a global in a numbered address space with
887 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]888
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]889<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]890@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]891</pre>
892
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]893</div>
894
895
896<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]897<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]898 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]899</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]900
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]901<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]902
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]903<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]904 optional <a href="#linkage">linkage type</a>, an optional
905 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]906 <a href="#callingconv">calling convention</a>,
907 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]908 <a href="#paramattrs">parameter attribute</a> for the return type, a function
909 name, a (possibly empty) argument list (each with optional
910 <a href="#paramattrs">parameter attributes</a>), optional
911 <a href="#fnattrs">function attributes</a>, an optional section, an optional
912 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
913 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]914
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]915<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
916 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]917 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]918 <a href="#callingconv">calling convention</a>,
919 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]920 <a href="#paramattrs">parameter attribute</a> for the return type, a function
921 name, a possibly empty list of arguments, an optional alignment, and an
922 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]923
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]924<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]925 (Control Flow Graph) for the function. Each basic block may optionally start
926 with a label (giving the basic block a symbol table entry), contains a list
927 of instructions, and ends with a <a href="#terminators">terminator</a>
928 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]929
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]930<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]931 executed on entrance to the function, and it is not allowed to have
932 predecessor basic blocks (i.e. there can not be any branches to the entry
933 block of a function). Because the block can have no predecessors, it also
934 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]935
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]936<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]937 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]938
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]939<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]940 the alignment is set to zero, the alignment of the function is set by the
941 target to whatever it feels convenient. If an explicit alignment is
942 specified, the function is forced to have at least that much alignment. All
943 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]944
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]945<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
946 be significant and two identical functions can be merged</p>.
947
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]948<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]949<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]950define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]951 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
952 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
953 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
954 [<a href="#gc">gc</a>] { ... }
955</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]956
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]957</div>
958
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]959<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]960<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]961 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]962</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]963
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]964<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]965
966<p>Aliases act as "second name" for the aliasee value (which can be either
967 function, global variable, another alias or bitcast of global value). Aliases
968 may have an optional <a href="#linkage">linkage type</a>, and an
969 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]970
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]971<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]972<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]973@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]974</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]975
976</div>
977
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]978<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]979<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]980 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]981</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]982
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]983<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]984
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]985<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]986 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]987 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]988
989<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]990<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]991; Some unnamed metadata nodes, which are referenced by the named metadata.
992!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]993!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]994!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]995; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]996!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]997</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]998
999</div>
1000
1001<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1002<h3>
1003 <a name="paramattrs">Parameter Attributes</a>
1004</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1005
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1006<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1007
1008<p>The return type and each parameter of a function type may have a set of
1009 <i>parameter attributes</i> associated with them. Parameter attributes are
1010 used to communicate additional information about the result or parameters of
1011 a function. Parameter attributes are considered to be part of the function,
1012 not of the function type, so functions with different parameter attributes
1013 can have the same function type.</p>
1014
1015<p>Parameter attributes are simple keywords that follow the type specified. If
1016 multiple parameter attributes are needed, they are space separated. For
1017 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1018
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1019<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1020declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1021declare i32 @atoi(i8 zeroext)
1022declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1023</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1024
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1025<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1026 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1027
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1028<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1029
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1030<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1033 should be zero-extended to the extent required by the target's ABI (which
1034 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1035 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1036
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1037 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1039 should be sign-extended to the extent required by the target's ABI (which
1040 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1041 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1042
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1043 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1044 <dd>This indicates that this parameter or return value should be treated in a
1045 special target-dependent fashion during while emitting code for a function
1046 call or return (usually, by putting it in a register as opposed to memory,
1047 though some targets use it to distinguish between two different kinds of
1048 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1049
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1050 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1051 <dd><p>This indicates that the pointer parameter should really be passed by
1052 value to the function. The attribute implies that a hidden copy of the
1053 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1054 is made between the caller and the callee, so the callee is unable to
1055 modify the value in the callee. This attribute is only valid on LLVM
1056 pointer arguments. It is generally used to pass structs and arrays by
1057 value, but is also valid on pointers to scalars. The copy is considered
1058 to belong to the caller not the callee (for example,
1059 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1060 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1061 values.</p>
1062
1063 <p>The byval attribute also supports specifying an alignment with
1064 the align attribute. It indicates the alignment of the stack slot to
1065 form and the known alignment of the pointer specified to the call site. If
1066 the alignment is not specified, then the code generator makes a
1067 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1068
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1069 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1070 <dd>This indicates that the pointer parameter specifies the address of a
1071 structure that is the return value of the function in the source program.
1072 This pointer must be guaranteed by the caller to be valid: loads and
1073 stores to the structure may be assumed by the callee to not to trap. This
1074 may only be applied to the first parameter. This is not a valid attribute
1075 for return values. </dd>
1076
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1077 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1078 <dd>This indicates that pointer values
1079 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1080 value do not alias pointer values which are not <i>based</i> on it,
1081 ignoring certain "irrelevant" dependencies.
1082 For a call to the parent function, dependencies between memory
1083 references from before or after the call and from those during the call
1084 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1085 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1086 The caller shares the responsibility with the callee for ensuring that
1087 these requirements are met.
1088 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1089 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1090<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1091 Note that this definition of <tt>noalias</tt> is intentionally
1092 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1093 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1094<br>
1095 For function return values, C99's <tt>restrict</tt> is not meaningful,
1096 while LLVM's <tt>noalias</tt> is.
1097 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1098
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1099 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1100 <dd>This indicates that the callee does not make any copies of the pointer
1101 that outlive the callee itself. This is not a valid attribute for return
1102 values.</dd>
1103
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1104 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1105 <dd>This indicates that the pointer parameter can be excised using the
1106 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1107 attribute for return values.</dd>
1108</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1109
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1110</div>
1111
1112<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1113<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1114 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1115</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1116
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1117<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1118
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1119<p>Each function may specify a garbage collector name, which is simply a
1120 string:</p>
1121
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1122<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1123define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1124</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1125
1126<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1127 collector which will cause the compiler to alter its output in order to
1128 support the named garbage collection algorithm.</p>
1129
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1130</div>
1131
1132<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1133<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1134 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1135</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1136
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1137<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1138
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1139<p>Function attributes are set to communicate additional information about a
1140 function. Function attributes are considered to be part of the function, not
1141 of the function type, so functions with different parameter attributes can
1142 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1143
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1144<p>Function attributes are simple keywords that follow the type specified. If
1145 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1146
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1147<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1148define void @f() noinline { ... }
1149define void @f() alwaysinline { ... }
1150define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1151define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1152</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1153
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1154<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1155 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1156 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1157 the backend should forcibly align the stack pointer. Specify the
1158 desired alignment, which must be a power of two, in parentheses.
1159
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1160 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1161 <dd>This attribute indicates that the inliner should attempt to inline this
1162 function into callers whenever possible, ignoring any active inlining size
1163 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1164
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1165 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1166 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1167 meaning the function can be patched and/or hooked even while it is
1168 loaded into memory. On x86, the function prologue will be preceded
1169 by six bytes of padding and will begin with a two-byte instruction.
1170 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1171 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1172
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1173 <dt><tt><b>nonlazybind</b></tt></dt>
1174 <dd>This attribute suppresses lazy symbol binding for the function. This
1175 may make calls to the function faster, at the cost of extra program
1176 startup time if the function is not called during program startup.</dd>
1177
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1178 <dt><tt><b>inlinehint</b></tt></dt>
1179 <dd>This attribute indicates that the source code contained a hint that inlining
1180 this function is desirable (such as the "inline" keyword in C/C++). It
1181 is just a hint; it imposes no requirements on the inliner.</dd>
1182
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1183 <dt><tt><b>naked</b></tt></dt>
1184 <dd>This attribute disables prologue / epilogue emission for the function.
1185 This can have very system-specific consequences.</dd>
1186
1187 <dt><tt><b>noimplicitfloat</b></tt></dt>
1188 <dd>This attributes disables implicit floating point instructions.</dd>
1189
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1190 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1191 <dd>This attribute indicates that the inliner should never inline this
1192 function in any situation. This attribute may not be used together with
1193 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1194
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1195 <dt><tt><b>noredzone</b></tt></dt>
1196 <dd>This attribute indicates that the code generator should not use a red
1197 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1198
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1199 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1200 <dd>This function attribute indicates that the function never returns
1201 normally. This produces undefined behavior at runtime if the function
1202 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1203
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1204 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1205 <dd>This function attribute indicates that the function never returns with an
1206 unwind or exceptional control flow. If the function does unwind, its
1207 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1208
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1209 <dt><tt><b>optsize</b></tt></dt>
1210 <dd>This attribute suggests that optimization passes and code generator passes
1211 make choices that keep the code size of this function low, and otherwise
1212 do optimizations specifically to reduce code size.</dd>
1213
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1214 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1215 <dd>This attribute indicates that the function computes its result (or decides
1216 to unwind an exception) based strictly on its arguments, without
1217 dereferencing any pointer arguments or otherwise accessing any mutable
1218 state (e.g. memory, control registers, etc) visible to caller functions.
1219 It does not write through any pointer arguments
1220 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1221 changes any state visible to callers. This means that it cannot unwind
1222 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1223 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1224
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1225 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1226 <dd>This attribute indicates that the function does not write through any
1227 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1228 arguments) or otherwise modify any state (e.g. memory, control registers,
1229 etc) visible to caller functions. It may dereference pointer arguments
1230 and read state that may be set in the caller. A readonly function always
1231 returns the same value (or unwinds an exception identically) when called
1232 with the same set of arguments and global state. It cannot unwind an
1233 exception by calling the <tt>C++</tt> exception throwing methods, but may
1234 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1235
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1236 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1237 <dd>This attribute indicates that the function should emit a stack smashing
1238 protector. It is in the form of a "canary"&mdash;a random value placed on
1239 the stack before the local variables that's checked upon return from the
1240 function to see if it has been overwritten. A heuristic is used to
1241 determine if a function needs stack protectors or not.<br>
1242<br>
1243 If a function that has an <tt>ssp</tt> attribute is inlined into a
1244 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1245 function will have an <tt>ssp</tt> attribute.</dd>
1246
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1247 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1248 <dd>This attribute indicates that the function should <em>always</em> emit a
1249 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1250 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1251<br>
1252 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1253 function that doesn't have an <tt>sspreq</tt> attribute or which has
1254 an <tt>ssp</tt> attribute, then the resulting function will have
1255 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindola163d6752011-07-25 15:27:59 +0000[diff] [blame]1256
1257 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1258 <dd>This attribute indicates that the ABI being targeted requires that
1259 an unwind table entry be produce for this function even if we can
1260 show that no exceptions passes by it. This is normally the case for
1261 the ELF x86-64 abi, but it can be disabled for some compilation
1262 units.</dd>
1263
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1264</dl>
1265
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1266</div>
1267
1268<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1269<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1270 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1271</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1272
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1273<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1274
1275<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1276 the GCC "file scope inline asm" blocks. These blocks are internally
1277 concatenated by LLVM and treated as a single unit, but may be separated in
1278 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1279
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1280<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1281module asm "inline asm code goes here"
1282module asm "more can go here"
1283</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1284
1285<p>The strings can contain any character by escaping non-printable characters.
1286 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]1287 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1288
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1289<p>The inline asm code is simply printed to the machine code .s file when
1290 assembly code is generated.</p>
1291
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1292</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1293
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1294<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1295<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1296 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1297</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1298
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1299<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1300
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1301<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1302 data is to be laid out in memory. The syntax for the data layout is
1303 simply:</p>
1304
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1305<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1306target datalayout = "<i>layout specification</i>"
1307</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1308
1309<p>The <i>layout specification</i> consists of a list of specifications
1310 separated by the minus sign character ('-'). Each specification starts with
1311 a letter and may include other information after the letter to define some
1312 aspect of the data layout. The specifications accepted are as follows:</p>
1313
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1314<dl>
1315 <dt><tt>E</tt></dt>
1316 <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]1317 bits with the most significance have the lowest address location.</dd>
1318
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1319 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1320 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1321 the bits with the least significance have the lowest address
1322 location.</dd>
1323
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1324 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1325 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1326 <i>preferred</i> alignments. All sizes are in bits. Specifying
1327 the <i>pref</i> alignment is optional. If omitted, the
1328 preceding <tt>:</tt> should be omitted too.</dd>
1329
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1330 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1331 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1332 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1333
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1334 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1335 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1336 <i>size</i>.</dd>
1337
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1338 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1339 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1340 <i>size</i>. Only values of <i>size</i> that are supported by the target
1341 will work. 32 (float) and 64 (double) are supported on all targets;
1342 80 or 128 (different flavors of long double) are also supported on some
1343 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1344
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1345 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1346 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1347 <i>size</i>.</dd>
1348
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1349 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1350 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1351 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1352
1353 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1354 <dd>This specifies a set of native integer widths for the target CPU
1355 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1356 "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]1357 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1358 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1359</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1360
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1361<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1362 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1363 specifications in the <tt>datalayout</tt> keyword. The default specifications
1364 are given in this list:</p>
1365
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1366<ul>
1367 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1368 <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]1369 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1370 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1371 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1372 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1373 <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]1374 alignment of 64-bits</li>
1375 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1376 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1377 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1378 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1379 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1380 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1381</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1382
1383<p>When LLVM is determining the alignment for a given type, it uses the
1384 following rules:</p>
1385
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1386<ol>
1387 <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]1388 specification is used.</li>
1389
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1390 <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]1391 smallest integer type that is larger than the bitwidth of the sought type
1392 is used. If none of the specifications are larger than the bitwidth then
1393 the the largest integer type is used. For example, given the default
1394 specifications above, the i7 type will use the alignment of i8 (next
1395 largest) while both i65 and i256 will use the alignment of i64 (largest
1396 specified).</li>
1397
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1398 <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]1399 largest vector type that is smaller than the sought vector type will be
1400 used as a fall back. This happens because &lt;128 x double&gt; can be
1401 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1402</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1403
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1404</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1405
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1406<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1407<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1408 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1409</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1410
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1411<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1412
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1413<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1414with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1415is undefined. Pointer values are associated with address ranges
1416according to the following rules:</p>
1417
1418<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1419 <li>A pointer value is associated with the addresses associated with
1420 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1421 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1422 range of the variable's storage.</li>
1423 <li>The result value of an allocation instruction is associated with
1424 the address range of the allocated storage.</li>
1425 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1426 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1427 <li>An integer constant other than zero or a pointer value returned
1428 from a function not defined within LLVM may be associated with address
1429 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1430 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1431 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1432</ul>
1433
1434<p>A pointer value is <i>based</i> on another pointer value according
1435 to the following rules:</p>
1436
1437<ul>
1438 <li>A pointer value formed from a
1439 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1440 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1441 <li>The result value of a
1442 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1443 of the <tt>bitcast</tt>.</li>
1444 <li>A pointer value formed by an
1445 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1446 pointer values that contribute (directly or indirectly) to the
1447 computation of the pointer's value.</li>
1448 <li>The "<i>based</i> on" relationship is transitive.</li>
1449</ul>
1450
1451<p>Note that this definition of <i>"based"</i> is intentionally
1452 similar to the definition of <i>"based"</i> in C99, though it is
1453 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1454
1455<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1456<tt><a href="#i_load">load</a></tt> merely indicates the size and
1457alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1458interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1459<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1460and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1461
1462<p>Consequently, type-based alias analysis, aka TBAA, aka
1463<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1464LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1465additional information which specialized optimization passes may use
1466to implement type-based alias analysis.</p>
1467
1468</div>
1469
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1470<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1471<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1472 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1473</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1474
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1475<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1476
1477<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1478href="#i_store"><tt>store</tt></a>s, and <a
1479href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1480The optimizers must not change the number of volatile operations or change their
1481order of execution relative to other volatile operations. The optimizers
1482<i>may</i> change the order of volatile operations relative to non-volatile
1483operations. This is not Java's "volatile" and has no cross-thread
1484synchronization behavior.</p>
1485
1486</div>
1487
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1488<!-- ======================================================================= -->
1489<h3>
1490 <a name="memmodel">Memory Model for Concurrent Operations</a>
1491</h3>
1492
1493<div>
1494
1495<p>The LLVM IR does not define any way to start parallel threads of execution
1496or to register signal handlers. Nonetheless, there are platform-specific
1497ways to create them, and we define LLVM IR's behavior in their presence. This
1498model is inspired by the C++0x memory model.</p>
1499
1500<p>We define a <i>happens-before</i> partial order as the least partial order
1501that</p>
1502<ul>
1503 <li>Is a superset of single-thread program order, and</li>
1504 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1505 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1506 by platform-specific techniques, like pthread locks, thread
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1507 creation, thread joining, etc., and by atomic instructions.
1508 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1509 </li>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1510</ul>
1511
1512<p>Note that program order does not introduce <i>happens-before</i> edges
1513between a thread and signals executing inside that thread.</p>
1514
1515<p>Every (defined) read operation (load instructions, memcpy, atomic
1516loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1517(defined) write operations (store instructions, atomic
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1518stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1519initialized globals are considered to have a write of the initializer which is
1520atomic and happens before any other read or write of the memory in question.
1521For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1522any write to the same byte, except:</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1523
1524<ul>
1525 <li>If <var>write<sub>1</sub></var> happens before
1526 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1527 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1528 does not see <var>write<sub>1</sub></var>.
Bill Wendling537603b2011-07-31 06:45:03 +0000[diff] [blame]1529 <li>If <var>R<sub>byte</sub></var> happens before
1530 <var>write<sub>3</sub></var>, then <var>R<sub>byte</sub></var> does not
1531 see <var>write<sub>3</sub></var>.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1532</ul>
1533
1534<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1535<ul>
1536 <li>If there is no write to the same byte that happens before
1537 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1538 <tt>undef</tt> for that byte.
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1539 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1540 <var>R<sub>byte</sub></var> returns the value written by that
1541 write.</li>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1542 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1543 <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]1544 values written. See the <a href="#ordering">Atomic Memory Ordering
1545 Constraints</a> section for additional constraints on how the choice
1546 is made.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1547 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1548</ul>
1549
1550<p><var>R</var> returns the value composed of the series of bytes it read.
1551This implies that some bytes within the value may be <tt>undef</tt>
1552<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1553defines the semantics of the operation; it doesn't mean that targets will
1554emit more than one instruction to read the series of bytes.</p>
1555
1556<p>Note that in cases where none of the atomic intrinsics are used, this model
1557places only one restriction on IR transformations on top of what is required
1558for single-threaded execution: introducing a store to a byte which might not
Eli Friedman4bc9f3c2011-08-02 01:15:34 +0000[diff] [blame]1559otherwise be stored is not allowed in general. (Specifically, in the case
1560where another thread might write to and read from an address, introducing a
1561store can change a load that may see exactly one write into a load that may
1562see multiple writes.)</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1563
1564<!-- FIXME: This model assumes all targets where concurrency is relevant have
1565a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1566none of the backends currently in the tree fall into this category; however,
1567there might be targets which care. If there are, we want a paragraph
1568like the following:
1569
1570Targets may specify that stores narrower than a certain width are not
1571available; on such a target, for the purposes of this model, treat any
1572non-atomic write with an alignment or width less than the minimum width
1573as if it writes to the relevant surrounding bytes.
1574-->
1575
1576</div>
1577
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1578<!-- ======================================================================= -->
1579<div class="doc_subsection">
1580 <a name="ordering">Atomic Memory Ordering Constraints</a>
1581</div>
1582
1583<div class="doc_text">
1584
1585<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
1586<a href="#i_atomicrmw"><code>atomicrmw</code></a>, and
1587<a href="#i_fence"><code>fence</code></a>) take an ordering parameter
1588that determines which other atomic instructions on the same address they
1589<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1590but are somewhat more colloquial. If these descriptions aren't precise enough,
1591check those specs. <a href="#i_fence"><code>fence</code></a> instructions
1592treat these orderings somewhat differently since they don't take an address.
1593See that instruction's documentation for details.</p>
1594
1595<!-- FIXME Note atomic load+store here once those get added. -->
1596
1597<dl>
1598<!-- FIXME: unordered is intended to be used for atomic load and store;
1599it isn't allowed for any instruction yet. -->
1600<dt><code>unordered</code></dt>
1601<dd>The set of values that can be read is governed by the happens-before
1602partial order. A value cannot be read unless some operation wrote it.
1603This is intended to provide a guarantee strong enough to model Java's
1604non-volatile shared variables. This ordering cannot be specified for
1605read-modify-write operations; it is not strong enough to make them atomic
1606in any interesting way.</dd>
1607<dt><code>monotonic</code></dt>
1608<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1609total order for modifications by <code>monotonic</code> operations on each
1610address. All modification orders must be compatible with the happens-before
1611order. There is no guarantee that the modification orders can be combined to
1612a global total order for the whole program (and this often will not be
1613possible). The read in an atomic read-modify-write operation
1614(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1615<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1616reads the value in the modification order immediately before the value it
1617writes. If one atomic read happens before another atomic read of the same
1618address, the later read must see the same value or a later value in the
1619address's modification order. This disallows reordering of
1620<code>monotonic</code> (or stronger) operations on the same address. If an
1621address is written <code>monotonic</code>ally by one thread, and other threads
1622<code>monotonic</code>ally read that address repeatedly, the other threads must
1623eventually see the write. This is intended to model C++'s relaxed atomic
1624variables.</dd>
1625<dt><code>acquire</code></dt>
1626<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1627reads a value written by a <code>release</code> atomic operation, it
1628<i>synchronizes-with</i> that operation.</dd>
1629<dt><code>release</code></dt>
1630<dd>In addition to the guarantees of <code>monotonic</code>,
1631a <i>synchronizes-with</i> edge may be formed by an <code>acquire</code>
1632operation.</dd>
1633<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
1634<code>acquire</code> and <code>release</code> operation on its address.</dd>
1635<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1636<dd>In addition to the guarantees of <code>acq_rel</code>
1637(<code>acquire</code> for an operation which only reads, <code>release</code>
1638for an operation which only writes), there is a global total order on all
1639sequentially-consistent operations on all addresses, which is consistent with
1640the <i>happens-before</i> partial order and with the modification orders of
1641all the affected addresses. Each sequentially-consistent read sees the last
1642preceding write to the same address in this global order. This is intended
1643to model C++'s sequentially-consistent atomic variables and Java's volatile
1644shared variables.</dd>
1645</dl>
1646
1647<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1648it only <i>synchronizes with</i> or participates in modification and seq_cst
1649total orderings with other operations running in the same thread (for example,
1650in signal handlers).</p>
1651
1652</div>
1653
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1654</div>
1655
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1656<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1657<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1658<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1659
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1660<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1661
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1662<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1663 intermediate representation. Being typed enables a number of optimizations
1664 to be performed on the intermediate representation directly, without having
1665 to do extra analyses on the side before the transformation. A strong type
1666 system makes it easier to read the generated code and enables novel analyses
1667 and transformations that are not feasible to perform on normal three address
1668 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1669
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1670<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1671<h3>
1672 <a name="t_classifications">Type Classifications</a>
1673</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1674
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1675<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1676
1677<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1678
1679<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1680 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1681 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1682 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1683 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1684 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1685 </tr>
1686 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1687 <td><a href="#t_floating">floating point</a></td>
1688 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1689 </tr>
1690 <tr>
1691 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1692 <td><a href="#t_integer">integer</a>,
1693 <a href="#t_floating">floating point</a>,
1694 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1695 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1696 <a href="#t_struct">structure</a>,
1697 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1698 <a href="#t_label">label</a>,
1699 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1700 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1701 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1702 <tr>
1703 <td><a href="#t_primitive">primitive</a></td>
1704 <td><a href="#t_label">label</a>,
1705 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1706 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1707 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1708 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1709 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1710 </tr>
1711 <tr>
1712 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1713 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1714 <a href="#t_function">function</a>,
1715 <a href="#t_pointer">pointer</a>,
1716 <a href="#t_struct">structure</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1717 <a href="#t_vector">vector</a>,
1718 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1719 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1720 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1721 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1722</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1723
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1724<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1725 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1726 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1727
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1728</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1729
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1730<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1731<h3>
1732 <a name="t_primitive">Primitive Types</a>
1733</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1734
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1735<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1736
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1737<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1738 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1739
1740<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1741<h4>
1742 <a name="t_integer">Integer Type</a>
1743</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1744
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1745<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1746
1747<h5>Overview:</h5>
1748<p>The integer type is a very simple type that simply specifies an arbitrary
1749 bit width for the integer type desired. Any bit width from 1 bit to
1750 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1751
1752<h5>Syntax:</h5>
1753<pre>
1754 iN
1755</pre>
1756
1757<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1758 value.</p>
1759
1760<h5>Examples:</h5>
1761<table class="layout">
1762 <tr class="layout">
1763 <td class="left"><tt>i1</tt></td>
1764 <td class="left">a single-bit integer.</td>
1765 </tr>
1766 <tr class="layout">
1767 <td class="left"><tt>i32</tt></td>
1768 <td class="left">a 32-bit integer.</td>
1769 </tr>
1770 <tr class="layout">
1771 <td class="left"><tt>i1942652</tt></td>
1772 <td class="left">a really big integer of over 1 million bits.</td>
1773 </tr>
1774</table>
1775
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1776</div>
1777
1778<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1779<h4>
1780 <a name="t_floating">Floating Point Types</a>
1781</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1782
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1783<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1784
1785<table>
1786 <tbody>
1787 <tr><th>Type</th><th>Description</th></tr>
1788 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1789 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1790 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1791 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1792 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1793 </tbody>
1794</table>
1795
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1796</div>
1797
1798<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1799<h4>
1800 <a name="t_x86mmx">X86mmx Type</a>
1801</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1802
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1803<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1804
1805<h5>Overview:</h5>
1806<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>
1807
1808<h5>Syntax:</h5>
1809<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1810 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1811</pre>
1812
1813</div>
1814
1815<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1816<h4>
1817 <a name="t_void">Void Type</a>
1818</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1819
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1820<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1821
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1822<h5>Overview:</h5>
1823<p>The void type does not represent any value and has no size.</p>
1824
1825<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1826<pre>
1827 void
1828</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1829
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1830</div>
1831
1832<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1833<h4>
1834 <a name="t_label">Label Type</a>
1835</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1836
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1837<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1838
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1839<h5>Overview:</h5>
1840<p>The label type represents code labels.</p>
1841
1842<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1843<pre>
1844 label
1845</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1846
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1847</div>
1848
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1849<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1850<h4>
1851 <a name="t_metadata">Metadata Type</a>
1852</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1853
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1854<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1855
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1856<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1857<p>The metadata type represents embedded metadata. No derived types may be
1858 created from metadata except for <a href="#t_function">function</a>
1859 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1860
1861<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1862<pre>
1863 metadata
1864</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1865
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1866</div>
1867
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1868</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1869
1870<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1871<h3>
1872 <a name="t_derived">Derived Types</a>
1873</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1874
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1875<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1876
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1877<p>The real power in LLVM comes from the derived types in the system. This is
1878 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1879 useful types. Each of these types contain one or more element types which
1880 may be a primitive type, or another derived type. For example, it is
1881 possible to have a two dimensional array, using an array as the element type
1882 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1883
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1884</div>
1885
1886
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1887<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1888<h4>
1889 <a name="t_aggregate">Aggregate Types</a>
1890</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1891
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1892<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1893
1894<p>Aggregate Types are a subset of derived types that can contain multiple
1895 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1896 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1897 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1898
1899</div>
1900
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1901<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1902<h4>
1903 <a name="t_array">Array Type</a>
1904</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1905
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1906<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1907
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1908<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1909<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1910 sequentially in memory. The array type requires a size (number of elements)
1911 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1912
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1913<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1914<pre>
1915 [&lt;# elements&gt; x &lt;elementtype&gt;]
1916</pre>
1917
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1918<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1919 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1920
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1921<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1922<table class="layout">
1923 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1924 <td class="left"><tt>[40 x i32]</tt></td>
1925 <td class="left">Array of 40 32-bit integer values.</td>
1926 </tr>
1927 <tr class="layout">
1928 <td class="left"><tt>[41 x i32]</tt></td>
1929 <td class="left">Array of 41 32-bit integer values.</td>
1930 </tr>
1931 <tr class="layout">
1932 <td class="left"><tt>[4 x i8]</tt></td>
1933 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1934 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1935</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1936<p>Here are some examples of multidimensional arrays:</p>
1937<table class="layout">
1938 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1939 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1940 <td class="left">3x4 array of 32-bit integer values.</td>
1941 </tr>
1942 <tr class="layout">
1943 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1944 <td class="left">12x10 array of single precision floating point values.</td>
1945 </tr>
1946 <tr class="layout">
1947 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1948 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1949 </tr>
1950</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1951
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1952<p>There is no restriction on indexing beyond the end of the array implied by
1953 a static type (though there are restrictions on indexing beyond the bounds
1954 of an allocated object in some cases). This means that single-dimension
1955 'variable sized array' addressing can be implemented in LLVM with a zero
1956 length array type. An implementation of 'pascal style arrays' in LLVM could
1957 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1958
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1959</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1960
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1961<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1962<h4>
1963 <a name="t_function">Function Type</a>
1964</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1965
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1966<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1967
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1968<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1969<p>The function type can be thought of as a function signature. It consists of
1970 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]1971 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1972
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1973<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1974<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1975 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1976</pre>
1977
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1978<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]1979 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1980 which indicates that the function takes a variable number of arguments.
1981 Variable argument functions can access their arguments with
1982 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1983 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1984 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1985
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1986<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1987<table class="layout">
1988 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1989 <td class="left"><tt>i32 (i32)</tt></td>
1990 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1991 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1992 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1993 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1994 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1995 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1996 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1997 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1998 </td>
1999 </tr><tr class="layout">
2000 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2001 <td class="left">A vararg function that takes at least one
2002 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2003 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]2004 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2005 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2006 </tr><tr class="layout">
2007 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]2008 <td class="left">A function taking an <tt>i32</tt>, returning a
2009 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2010 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2011 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2012</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2013
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2014</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2015
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2016<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2017<h4>
2018 <a name="t_struct">Structure Type</a>
2019</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2020
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2021<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2022
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2023<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2024<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2025 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]2026
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]2027<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2028 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2029 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2030 Structures in registers are accessed using the
2031 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2032 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2033
2034<p>Structures may optionally be "packed" structures, which indicate that the
2035 alignment of the struct is one byte, and that there is no padding between
2036 the elements. In non-packed structs, padding between field types is defined
2037 by the target data string to match the underlying processor.</p>
2038
2039<p>Structures can either be "anonymous" or "named". An anonymous structure is
2040 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
2041 are always defined at the top level with a name. Anonmyous types are uniqued
2042 by their contents and can never be recursive since there is no way to write
2043 one. Named types can be recursive.
2044</p>
2045
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2046<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2047<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2048 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
2049 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2050</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2051
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2052<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2053<table class="layout">
2054 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2055 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2056 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2057 </tr>
2058 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2059 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2060 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2061 second element is a <a href="#t_pointer">pointer</a> to a
2062 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2063 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2064 </tr>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2065 <tr class="layout">
2066 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2067 <td class="left">A packed struct known to be 5 bytes in size.</td>
2068 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2069</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2070
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2071</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2072
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2073<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2074<h4>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2075 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2076</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2077
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2078<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2079
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2080<h5>Overview:</h5>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2081<p>Opaque structure types are used to represent named structure types that do
2082 not have a body specified. This corresponds (for example) to the C notion of
2083 a forward declared structure.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2084
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2085<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2086<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2087 %X = type opaque
2088 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2089</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2090
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2091<h5>Examples:</h5>
2092<table class="layout">
2093 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2094 <td class="left"><tt>opaque</tt></td>
2095 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2096 </tr>
2097</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2098
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2099</div>
2100
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2101
2102
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2103<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2104<h4>
2105 <a name="t_pointer">Pointer Type</a>
2106</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2107
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2108<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2109
2110<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]2111<p>The pointer type is used to specify memory locations.
2112 Pointers are commonly used to reference objects in memory.</p>
2113
2114<p>Pointer types may have an optional address space attribute defining the
2115 numbered address space where the pointed-to object resides. The default
2116 address space is number zero. The semantics of non-zero address
2117 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2118
2119<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2120 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2121
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2122<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2123<pre>
2124 &lt;type&gt; *
2125</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2126
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2127<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2128<table class="layout">
2129 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2130 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2131 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2132 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2133 </tr>
2134 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]2135 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2136 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2137 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2138 <tt>i32</tt>.</td>
2139 </tr>
2140 <tr class="layout">
2141 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2142 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2143 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2144 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2145</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2146
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2147</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2148
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2149<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2150<h4>
2151 <a name="t_vector">Vector Type</a>
2152</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2153
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2154<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2155
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2156<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2157<p>A vector type is a simple derived type that represents a vector of elements.
2158 Vector types are used when multiple primitive data are operated in parallel
2159 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]2160 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2161 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2162
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2163<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2164<pre>
2165 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2166</pre>
2167
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]2168<p>The number of elements is a constant integer value larger than 0; elementtype
2169 may be any integer or floating point type. Vectors of size zero are not
2170 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2171
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2172<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2173<table class="layout">
2174 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2175 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2176 <td class="left">Vector of 4 32-bit integer values.</td>
2177 </tr>
2178 <tr class="layout">
2179 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2180 <td class="left">Vector of 8 32-bit floating-point values.</td>
2181 </tr>
2182 <tr class="layout">
2183 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2184 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2185 </tr>
2186</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2187
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2188</div>
2189
Bill Wendlingae8b5ea2011-07-31 06:47:33 +0000[diff] [blame]2190</div>
2191
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2192<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2193<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2194<!-- *********************************************************************** -->
2195
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2196<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2197
2198<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2199 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2200
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2201<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2202<h3>
2203 <a name="simpleconstants">Simple Constants</a>
2204</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2205
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2206<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2207
2208<dl>
2209 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2210 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2211 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2212
2213 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2214 <dd>Standard integers (such as '4') are constants of
2215 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2216 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2217
2218 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2219 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2220 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2221 notation (see below). The assembler requires the exact decimal value of a
2222 floating-point constant. For example, the assembler accepts 1.25 but
2223 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2224 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2225
2226 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2227 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2228 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2229</dl>
2230
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2231<p>The one non-intuitive notation for constants is the hexadecimal form of
2232 floating point constants. For example, the form '<tt>double
2233 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2234 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2235 constants are required (and the only time that they are generated by the
2236 disassembler) is when a floating point constant must be emitted but it cannot
2237 be represented as a decimal floating point number in a reasonable number of
2238 digits. For example, NaN's, infinities, and other special values are
2239 represented in their IEEE hexadecimal format so that assembly and disassembly
2240 do not cause any bits to change in the constants.</p>
2241
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2242<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2243 represented using the 16-digit form shown above (which matches the IEEE754
2244 representation for double); float values must, however, be exactly
2245 representable as IEE754 single precision. Hexadecimal format is always used
2246 for long double, and there are three forms of long double. The 80-bit format
2247 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2248 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2249 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2250 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2251 currently supported target uses this format. Long doubles will only work if
2252 they match the long double format on your target. All hexadecimal formats
2253 are big-endian (sign bit at the left).</p>
2254
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2255<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2256</div>
2257
2258<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2259<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2260<a name="aggregateconstants"></a> <!-- old anchor -->
2261<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2262</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2263
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2264<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2265
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2266<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2267 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2268
2269<dl>
2270 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2271 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2272 type definitions (a comma separated list of elements, surrounded by braces
2273 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2274 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2275 Structure constants must have <a href="#t_struct">structure type</a>, and
2276 the number and types of elements must match those specified by the
2277 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2278
2279 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2280 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2281 definitions (a comma separated list of elements, surrounded by square
2282 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2283 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2284 the number and types of elements must match those specified by the
2285 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2286
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2287 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2288 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2289 definitions (a comma separated list of elements, surrounded by
2290 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2291 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2292 have <a href="#t_vector">vector type</a>, and the number and types of
2293 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2294
2295 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2296 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2297 value to zero of <em>any</em> type, including scalar and
2298 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2299 This is often used to avoid having to print large zero initializers
2300 (e.g. for large arrays) and is always exactly equivalent to using explicit
2301 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2302
2303 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2304 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2305 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2306 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2307 be interpreted as part of the instruction stream, metadata is a place to
2308 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2309</dl>
2310
2311</div>
2312
2313<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2314<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2315 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2316</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2317
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2318<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2319
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2320<p>The addresses of <a href="#globalvars">global variables</a>
2321 and <a href="#functionstructure">functions</a> are always implicitly valid
2322 (link-time) constants. These constants are explicitly referenced when
2323 the <a href="#identifiers">identifier for the global</a> is used and always
2324 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2325 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2326
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2327<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2328@X = global i32 17
2329@Y = global i32 42
2330@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2331</pre>
2332
2333</div>
2334
2335<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2336<h3>
2337 <a name="undefvalues">Undefined Values</a>
2338</h3>
2339
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2340<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2341
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2342<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]2343 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2344 Undefined values may be of any type (other than '<tt>label</tt>'
2345 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2346
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2347<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2348 program is well defined no matter what value is used. This gives the
2349 compiler more freedom to optimize. Here are some examples of (potentially
2350 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2351
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2352
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2353<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2354 %A = add %X, undef
2355 %B = sub %X, undef
2356 %C = xor %X, undef
2357Safe:
2358 %A = undef
2359 %B = undef
2360 %C = undef
2361</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2362
2363<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]2364 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]2365
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2366<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2367 %A = or %X, undef
2368 %B = and %X, undef
2369Safe:
2370 %A = -1
2371 %B = 0
2372Unsafe:
2373 %A = undef
2374 %B = undef
2375</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2376
2377<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2378 For example, if <tt>%X</tt> has a zero bit, then the output of the
2379 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2380 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2381 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2382 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2383 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2384 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2385 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2386
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2387<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2388 %A = select undef, %X, %Y
2389 %B = select undef, 42, %Y
2390 %C = select %X, %Y, undef
2391Safe:
2392 %A = %X (or %Y)
2393 %B = 42 (or %Y)
2394 %C = %Y
2395Unsafe:
2396 %A = undef
2397 %B = undef
2398 %C = undef
2399</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2400
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2401<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2402 branch) conditions can go <em>either way</em>, but they have to come from one
2403 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2404 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2405 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2406 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2407 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2408 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2409
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2410<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2411 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2412
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2413 %B = undef
2414 %C = xor %B, %B
2415
2416 %D = undef
2417 %E = icmp lt %D, 4
2418 %F = icmp gte %D, 4
2419
2420Safe:
2421 %A = undef
2422 %B = undef
2423 %C = undef
2424 %D = undef
2425 %E = undef
2426 %F = undef
2427</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2428
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2429<p>This example points out that two '<tt>undef</tt>' operands are not
2430 necessarily the same. This can be surprising to people (and also matches C
2431 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2432 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2433 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2434 its value over its "live range". This is true because the variable doesn't
2435 actually <em>have a live range</em>. Instead, the value is logically read
2436 from arbitrary registers that happen to be around when needed, so the value
2437 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2438 need to have the same semantics or the core LLVM "replace all uses with"
2439 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2440
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2441<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2442 %A = fdiv undef, %X
2443 %B = fdiv %X, undef
2444Safe:
2445 %A = undef
2446b: unreachable
2447</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2448
2449<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2450 value</em> and <em>undefined behavior</em>. An undefined value (like
2451 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2452 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2453 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2454 defined on SNaN's. However, in the second example, we can make a more
2455 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2456 arbitrary value, we are allowed to assume that it could be zero. Since a
2457 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2458 the operation does not execute at all. This allows us to delete the divide and
2459 all code after it. Because the undefined operation "can't happen", the
2460 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2461
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2462<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2463a: store undef -> %X
2464b: store %X -> undef
2465Safe:
2466a: &lt;deleted&gt;
2467b: unreachable
2468</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2469
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2470<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2471 undefined value can be assumed to not have any effect; we can assume that the
2472 value is overwritten with bits that happen to match what was already there.
2473 However, a store <em>to</em> an undefined location could clobber arbitrary
2474 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2475
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2476</div>
2477
2478<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2479<h3>
2480 <a name="trapvalues">Trap Values</a>
2481</h3>
2482
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2483<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2484
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2485<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2486 instead of representing an unspecified bit pattern, they represent the
2487 fact that an instruction or constant expression which cannot evoke side
2488 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2489 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2490
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2491<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]2492 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2493 <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]2494
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2495<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2496
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2497<ul>
2498<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2499 their operands.</li>
2500
2501<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2502 to their dynamic predecessor basic block.</li>
2503
2504<li>Function arguments depend on the corresponding actual argument values in
2505 the dynamic callers of their functions.</li>
2506
2507<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2508 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2509 control back to them.</li>
2510
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2511<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2512 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2513 or exception-throwing call instructions that dynamically transfer control
2514 back to them.</li>
2515
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2516<li>Non-volatile loads and stores depend on the most recent stores to all of the
2517 referenced memory addresses, following the order in the IR
2518 (including loads and stores implied by intrinsics such as
2519 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2520
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2521<!-- TODO: In the case of multiple threads, this only applies if the store
2522 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2523
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2524<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2525
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2526<li>An instruction with externally visible side effects depends on the most
2527 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2528 the order in the IR. (This includes
2529 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2530
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2531<li>An instruction <i>control-depends</i> on a
2532 <a href="#terminators">terminator instruction</a>
2533 if the terminator instruction has multiple successors and the instruction
2534 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2535 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2536
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2537<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2538 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2539 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2540 successor.</li>
2541
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2542<li>Dependence is transitive.</li>
2543
2544</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2545
2546<p>Whenever a trap value is generated, all values which depend on it evaluate
2547 to trap. If they have side effects, the evoke their side effects as if each
2548 operand with a trap value were undef. If they have externally-visible side
2549 effects, the behavior is undefined.</p>
2550
2551<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2552
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2553<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2554entry:
2555 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2556 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2557 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2558 store i32 0, i32* %trap_yet_again ; undefined behavior
2559
2560 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2561 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2562
2563 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2564
2565 %narrowaddr = bitcast i32* @g to i16*
2566 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2567 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2568 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2569
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2570 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2571 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2572
2573true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2574 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2575 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2576 br label %end
2577
2578end:
2579 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2580 ; Both edges into this PHI are
2581 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2582 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2583
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2584 volatile store i32 0, i32* @g ; This would depend on the store in %true
2585 ; if %cmp is true, or the store in %entry
2586 ; otherwise, so this is undefined behavior.
2587
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2588 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2589 ; The same branch again, but this time the
2590 ; true block doesn't have side effects.
2591
2592second_true:
2593 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2594 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2595
2596second_end:
2597 volatile store i32 0, i32* @g ; This time, the instruction always depends
2598 ; on the store in %end. Also, it is
2599 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2600 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2601 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2602</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2603
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2604</div>
2605
2606<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2607<h3>
2608 <a name="blockaddress">Addresses of Basic Blocks</a>
2609</h3>
2610
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2611<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2612
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2613<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2614
2615<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2616 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2617 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2618
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2619<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2620 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2621 comparisons against null. Pointer equality tests between labels addresses
2622 results in undefined behavior &mdash; though, again, comparison against null
2623 is ok, and no label is equal to the null pointer. This may be passed around
2624 as an opaque pointer sized value as long as the bits are not inspected. This
2625 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2626 long as the original value is reconstituted before the <tt>indirectbr</tt>
2627 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2628
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2629<p>Finally, some targets may provide defined semantics when using the value as
2630 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2631
2632</div>
2633
2634
2635<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2636<h3>
2637 <a name="constantexprs">Constant Expressions</a>
2638</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2639
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2640<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2641
2642<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2643 to be used as constants. Constant expressions may be of
2644 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2645 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2646 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2647
2648<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2649 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2650 <dd>Truncate a constant to another type. The bit size of CST must be larger
2651 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2652
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2653 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2654 <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]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>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2658 <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]2659 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2660
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2661 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2662 <dd>Truncate a floating point constant to another floating point type. The
2663 size of CST must be larger than the size of TYPE. Both types must be
2664 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2665
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2666 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2667 <dd>Floating point extend a constant to another type. The size of CST must be
2668 smaller or equal to the size of TYPE. Both types must be floating
2669 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2670
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2671 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2672 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2673 constant. TYPE must be a scalar or vector integer type. CST must be of
2674 scalar or vector floating point type. Both CST and TYPE must be scalars,
2675 or vectors of the same number of elements. If the value won't fit in the
2676 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2677
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2678 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2679 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2680 constant. TYPE must be a scalar or vector integer type. CST must be of
2681 scalar or vector floating point type. Both CST and TYPE must be scalars,
2682 or vectors of the same number of elements. If the value won't fit in the
2683 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2684
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2685 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2686 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2687 constant. TYPE must be a scalar or vector floating point type. CST must be
2688 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2689 vectors of the same number of elements. If the value won't fit in the
2690 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2691
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2692 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2693 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2694 constant. TYPE must be a scalar or vector floating point type. CST must be
2695 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2696 vectors of the same number of elements. If the value won't fit in the
2697 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2698
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2699 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2700 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2701 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2702 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2703 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2704
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2705 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2706 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2707 type. CST must be of integer type. The CST value is zero extended,
2708 truncated, or unchanged to make it fit in a pointer size. This one is
2709 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2710
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2711 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2712 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2713 are the same as those for the <a href="#i_bitcast">bitcast
2714 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2715
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2716 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2717 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2718 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2719 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2720 instruction, the index list may have zero or more indexes, which are
2721 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2722
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2723 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2724 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2725
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2726 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2727 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2728
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2729 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2730 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on 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>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2733 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2734 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2735
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2736 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2737 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2738 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2739
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2740 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2741 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2742 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2743
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2744 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2745 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2746 constants. The index list is interpreted in a similar manner as indices in
2747 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2748 index value must be specified.</dd>
2749
2750 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2751 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2752 constants. The index list is interpreted in a similar manner as indices in
2753 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2754 index value must be specified.</dd>
2755
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2756 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2757 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2758 be any of the <a href="#binaryops">binary</a>
2759 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2760 on operands are the same as those for the corresponding instruction
2761 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2762</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2763
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2764</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2765
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2766</div>
2767
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2768<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2769<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2770<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2771<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2772<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2773<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2774<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2775</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2776
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2777<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2778
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2779<p>LLVM supports inline assembler expressions (as opposed
2780 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2781 a special value. This value represents the inline assembler as a string
2782 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2783 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2784 expression has side effects, and a flag indicating whether the function
2785 containing the asm needs to align its stack conservatively. An example
2786 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2787
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2788<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2789i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2790</pre>
2791
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2792<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2793 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2794 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2795
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2796<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2797%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]2798</pre>
2799
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2800<p>Inline asms with side effects not visible in the constraint list must be
2801 marked as having side effects. This is done through the use of the
2802 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2803
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2804<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2805call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2806</pre>
2807
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2808<p>In some cases inline asms will contain code that will not work unless the
2809 stack is aligned in some way, such as calls or SSE instructions on x86,
2810 yet will not contain code that does that alignment within the asm.
2811 The compiler should make conservative assumptions about what the asm might
2812 contain and should generate its usual stack alignment code in the prologue
2813 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2814
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2815<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2816call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2817</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2818
2819<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2820 first.</p>
2821
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2822<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2823 documented here. Constraints on what can be done (e.g. duplication, moving,
2824 etc need to be documented). This is probably best done by reference to
2825 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2826
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2827<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2828<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2829</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2830
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2831<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2832
2833<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2834 attached to it that contains a list of constant integers. If present, the
2835 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2836 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2837 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2838 source code that produced it. For example:</p>
2839
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2840<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2841call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2842...
2843!42 = !{ i32 1234567 }
2844</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2845
2846<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]2847 IR. If the MDNode contains multiple constants, the code generator will use
2848 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]2849
2850</div>
2851
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2852</div>
2853
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2854<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2855<h3>
2856 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2857</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2858
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2859<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2860
2861<p>LLVM IR allows metadata to be attached to instructions in the program that
2862 can convey extra information about the code to the optimizers and code
2863 generator. One example application of metadata is source-level debug
2864 information. There are two metadata primitives: strings and nodes. All
2865 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2866 preceding exclamation point ('<tt>!</tt>').</p>
2867
2868<p>A metadata string is a string surrounded by double quotes. It can contain
2869 any character by escaping non-printable characters with "\xx" where "xx" is
2870 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2871
2872<p>Metadata nodes are represented with notation similar to structure constants
2873 (a comma separated list of elements, surrounded by braces and preceded by an
2874 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2875 10}</tt>". Metadata nodes can have any values as their operand.</p>
2876
2877<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2878 metadata nodes, which can be looked up in the module symbol table. For
2879 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2880
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2881<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2882 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2883
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2884<div class="doc_code">
2885<pre>
2886call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2887</pre>
2888</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2889
2890<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2891 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2892
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2893<div class="doc_code">
2894<pre>
2895%indvar.next = add i64 %indvar, 1, !dbg !21
2896</pre>
2897</div>
2898
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2899</div>
2900
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2901</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2902
2903<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2904<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2905 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2906</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2907<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2908<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2909<p>LLVM has a number of "magic" global variables that contain data that affect
2910code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2911of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2912section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2913by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2914
2915<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2916<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2917<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2918</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2919
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2920<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2921
2922<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2923href="#linkage_appending">appending linkage</a>. This array contains a list of
2924pointers to global variables and functions which may optionally have a pointer
2925cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2926
2927<pre>
2928 @X = global i8 4
2929 @Y = global i32 123
2930
2931 @llvm.used = appending global [2 x i8*] [
2932 i8* @X,
2933 i8* bitcast (i32* @Y to i8*)
2934 ], section "llvm.metadata"
2935</pre>
2936
2937<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2938compiler, assembler, and linker are required to treat the symbol as if there is
2939a reference to the global that it cannot see. For example, if a variable has
2940internal linkage and no references other than that from the <tt>@llvm.used</tt>
2941list, it cannot be deleted. This is commonly used to represent references from
2942inline asms and other things the compiler cannot "see", and corresponds to
2943"attribute((used))" in GNU C.</p>
2944
2945<p>On some targets, the code generator must emit a directive to the assembler or
2946object file to prevent the assembler and linker from molesting the symbol.</p>
2947
2948</div>
2949
2950<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2951<h3>
2952 <a name="intg_compiler_used">
2953 The '<tt>llvm.compiler.used</tt>' Global Variable
2954 </a>
2955</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2956
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2957<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2958
2959<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2960<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2961touching the symbol. On targets that support it, this allows an intelligent
2962linker to optimize references to the symbol without being impeded as it would be
2963by <tt>@llvm.used</tt>.</p>
2964
2965<p>This is a rare construct that should only be used in rare circumstances, and
2966should not be exposed to source languages.</p>
2967
2968</div>
2969
2970<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2971<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2972<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2973</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2974
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2975<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2976<pre>
2977%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2978@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2979</pre>
2980<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.
2981</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2982
2983</div>
2984
2985<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2986<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2987<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2988</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2989
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2990<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2991<pre>
2992%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2993@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2994</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2995
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2996<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.
2997</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2998
2999</div>
3000
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3001</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3002
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]3003<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3004<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3005<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3006
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3007<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3008
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3009<p>The LLVM instruction set consists of several different classifications of
3010 instructions: <a href="#terminators">terminator
3011 instructions</a>, <a href="#binaryops">binary instructions</a>,
3012 <a href="#bitwiseops">bitwise binary instructions</a>,
3013 <a href="#memoryops">memory instructions</a>, and
3014 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3015
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3016<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3017<h3>
3018 <a name="terminators">Terminator Instructions</a>
3019</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3020
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3021<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3022
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3023<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3024 in a program ends with a "Terminator" instruction, which indicates which
3025 block should be executed after the current block is finished. These
3026 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3027 control flow, not values (the one exception being the
3028 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3029
Chris Lattnerd3d65ab2011-08-02 20:29:13 +0000[diff] [blame]3030<p>The terminator instructions are:
3031 '<a href="#i_ret"><tt>ret</tt></a>',
3032 '<a href="#i_br"><tt>br</tt></a>',
3033 '<a href="#i_switch"><tt>switch</tt></a>',
3034 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>',
3035 '<a href="#i_invoke"><tt>invoke</tt></a>',
3036 '<a href="#i_unwind"><tt>unwind</tt></a>',
3037 '<a href="#i_resume"><tt>resume</tt></a>', and
3038 '<a href="#i_unreachable"><tt>unreachable</tt></a>'.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3039
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3040<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3041<h4>
3042 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3043</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3044
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3045<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3046
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3047<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3048<pre>
3049 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]3050 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3051</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3052
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3053<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3054<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3055 a value) from a function back to the caller.</p>
3056
3057<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3058 value and then causes control flow, and one that just causes control flow to
3059 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3060
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3061<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3062<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3063 return value. The type of the return value must be a
3064 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3065
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3066<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3067 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3068 value or a return value with a type that does not match its type, or if it
3069 has a void return type and contains a '<tt>ret</tt>' instruction with a
3070 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3071
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3072<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3073<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3074 the calling function's context. If the caller is a
3075 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3076 instruction after the call. If the caller was an
3077 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3078 the beginning of the "normal" destination block. If the instruction returns
3079 a value, that value shall set the call or invoke instruction's return
3080 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3081
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3082<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3083<pre>
3084 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3085 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]3086 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]3087</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3088
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3089</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3090<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3091<h4>
3092 <a name="i_br">'<tt>br</tt>' Instruction</a>
3093</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3094
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3095<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3096
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3097<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3098<pre>
Bill Wendling16b86742011-07-26 10:41:15 +0000[diff] [blame]3099 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3100 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3101</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3102
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3103<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3104<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3105 different basic block in the current function. There are two forms of this
3106 instruction, corresponding to a conditional branch and an unconditional
3107 branch.</p>
3108
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3109<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3110<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3111 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3112 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3113 target.</p>
3114
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3115<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3116<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3117 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3118 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3119 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3120
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3121<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3122<pre>
3123Test:
3124 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3125 br i1 %cond, label %IfEqual, label %IfUnequal
3126IfEqual:
3127 <a href="#i_ret">ret</a> i32 1
3128IfUnequal:
3129 <a href="#i_ret">ret</a> i32 0
3130</pre>
3131
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3132</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3133
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3134<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3135<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3136 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3137</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3138
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3139<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3140
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3141<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3142<pre>
3143 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3144</pre>
3145
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3146<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3147<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]3148 several different places. It is a generalization of the '<tt>br</tt>'
3149 instruction, allowing a branch to occur to one of many possible
3150 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3151
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3152<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3153<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3154 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3155 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3156 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3157
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3158<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3159<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3160 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3161 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3162 transferred to the corresponding destination; otherwise, control flow is
3163 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3164
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3165<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3166<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3167 <tt>switch</tt> instruction, this instruction may be code generated in
3168 different ways. For example, it could be generated as a series of chained
3169 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3170
3171<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3172<pre>
3173 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3174 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3175 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3176
3177 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3178 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3179
3180 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3181 switch i32 %val, label %otherwise [ i32 0, label %onzero
3182 i32 1, label %onone
3183 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3184</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3185
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3186</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3187
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3188
3189<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3190<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3191 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3192</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3193
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3194<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3195
3196<h5>Syntax:</h5>
3197<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3198 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]3199</pre>
3200
3201<h5>Overview:</h5>
3202
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3203<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3204 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3205 "<tt>address</tt>". Address must be derived from a <a
3206 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3207
3208<h5>Arguments:</h5>
3209
3210<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3211 rest of the arguments indicate the full set of possible destinations that the
3212 address may point to. Blocks are allowed to occur multiple times in the
3213 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3214
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3215<p>This destination list is required so that dataflow analysis has an accurate
3216 understanding of the CFG.</p>
3217
3218<h5>Semantics:</h5>
3219
3220<p>Control transfers to the block specified in the address argument. All
3221 possible destination blocks must be listed in the label list, otherwise this
3222 instruction has undefined behavior. This implies that jumps to labels
3223 defined in other functions have undefined behavior as well.</p>
3224
3225<h5>Implementation:</h5>
3226
3227<p>This is typically implemented with a jump through a register.</p>
3228
3229<h5>Example:</h5>
3230<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3231 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3232</pre>
3233
3234</div>
3235
3236
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3237<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3238<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3239 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3240</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3241
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3242<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3243
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3244<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3245<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3246 &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]3247 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3248</pre>
3249
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3250<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3251<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3252 function, with the possibility of control flow transfer to either the
3253 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3254 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3255 control flow will return to the "normal" label. If the callee (or any
3256 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3257 instruction, control is interrupted and continued at the dynamically nearest
3258 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3259
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3260<p>The '<tt>exception</tt>' label is a
3261 <i><a href="ExceptionHandling.html#overview">landing pad</a></i> for the
3262 exception. As such, '<tt>exception</tt>' label is required to have the
3263 "<a href="#i_landingpad"><tt>landingpad</tt></a>" instruction, which contains
3264 the information about about the behavior of the program after unwinding
3265 happens, as its first non-PHI instruction. The restrictions on the
3266 "<tt>landingpad</tt>" instruction's tightly couples it to the
3267 "<tt>invoke</tt>" instruction, so that the important information contained
3268 within the "<tt>landingpad</tt>" instruction can't be lost through normal
3269 code motion.</p>
3270
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3271<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3272<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3273
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3274<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3275 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3276 convention</a> the call should use. If none is specified, the call
3277 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3278
3279 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3280 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3281 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3282
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3283 <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]3284 function value being invoked. In most cases, this is a direct function
3285 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3286 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3287
3288 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3289 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3290
3291 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3292 signature argument types and parameter attributes. All arguments must be
3293 of <a href="#t_firstclass">first class</a> type. If the function
3294 signature indicates the function accepts a variable number of arguments,
3295 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3296
3297 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3298 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3299
3300 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3301 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3302
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3303 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3304 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3305 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3306</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3307
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3308<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3309<p>This instruction is designed to operate as a standard
3310 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3311 primary difference is that it establishes an association with a label, which
3312 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3313
3314<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3315 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3316 exception. Additionally, this is important for implementation of
3317 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3318
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3319<p>For the purposes of the SSA form, the definition of the value returned by the
3320 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3321 block to the "normal" label. If the callee unwinds then no return value is
3322 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3323
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3324<p>Note that the code generator does not yet completely support unwind, and
3325that the invoke/unwind semantics are likely to change in future versions.</p>
3326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3327<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3328<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3329 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3330 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3331 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3332 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3333</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3334
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3335</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3336
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3337<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3338
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3339<h4>
3340 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3341</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3342
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3343<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3344
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3345<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3346<pre>
3347 unwind
3348</pre>
3349
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3350<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3351<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3352 at the first callee in the dynamic call stack which used
3353 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3354 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3355
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3356<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3357<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3358 immediately halt. The dynamic call stack is then searched for the
3359 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3360 Once found, execution continues at the "exceptional" destination block
3361 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3362 instruction in the dynamic call chain, undefined behavior results.</p>
3363
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3364<p>Note that the code generator does not yet completely support unwind, and
3365that the invoke/unwind semantics are likely to change in future versions.</p>
3366
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3367</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3368
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3369 <!-- _______________________________________________________________________ -->
3370
3371<h4>
3372 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3373</h4>
3374
3375<div>
3376
3377<h5>Syntax:</h5>
3378<pre>
3379 resume &lt;type&gt; &lt;value&gt;
3380</pre>
3381
3382<h5>Overview:</h5>
3383<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3384 successors.</p>
3385
3386<h5>Arguments:</h5>
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3387<p>The '<tt>resume</tt>' instruction requires one argument, which must have the
Bill Wendlingc5a13612011-08-03 18:37:32 +0000[diff] [blame]3388 same type as the result of any '<tt>landingpad</tt>' instruction in the same
3389 function.</p>
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3390
3391<h5>Semantics:</h5>
3392<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3393 (in-flight) exception whose unwinding was interrupted with
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3394 a <a href="#i_landingpad"><tt>landingpad</tt></a> instruction.</p>
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3395
3396<h5>Example:</h5>
3397<pre>
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]3398 resume { i8*, i32 } %exn
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3399</pre>
3400
3401</div>
3402
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3403<!-- _______________________________________________________________________ -->
3404
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3405<h4>
3406 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3407</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3408
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3409<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3410
3411<h5>Syntax:</h5>
3412<pre>
3413 unreachable
3414</pre>
3415
3416<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3417<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3418 instruction is used to inform the optimizer that a particular portion of the
3419 code is not reachable. This can be used to indicate that the code after a
3420 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3421
3422<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3423<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3424
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3425</div>
3426
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3427</div>
3428
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3429<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3430<h3>
3431 <a name="binaryops">Binary Operations</a>
3432</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3433
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3434<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3435
3436<p>Binary operators are used to do most of the computation in a program. They
3437 require two operands of the same type, execute an operation on them, and
3438 produce a single value. The operands might represent multiple data, as is
3439 the case with the <a href="#t_vector">vector</a> data type. The result value
3440 has the same type as its operands.</p>
3441
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3442<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3443
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3444<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3445<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3446 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3447</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3448
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3449<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3450
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3451<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3452<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3453 &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]3454 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3455 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3456 &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]3457</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3458
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3459<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3460<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3461
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3462<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3463<p>The two arguments to the '<tt>add</tt>' instruction must
3464 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3465 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3466
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3467<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3468<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3469
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3470<p>If the sum has unsigned overflow, the result returned is the mathematical
3471 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]3472
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3473<p>Because LLVM integers use a two's complement representation, this instruction
3474 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3475
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3476<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3477 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3478 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3479 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3480 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3481
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3482<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3483<pre>
3484 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3485</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3486
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3487</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3488
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3489<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3490<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3491 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3492</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3493
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3494<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3495
3496<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3497<pre>
3498 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3499</pre>
3500
3501<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3502<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3503
3504<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3505<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3506 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3507 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3508
3509<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3510<p>The value produced is the floating point sum of the two operands.</p>
3511
3512<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3513<pre>
3514 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3515</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3516
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3517</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3518
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3519<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3520<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3521 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3522</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3523
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3524<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3525
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3526<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3527<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3528 &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]3529 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3530 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3531 &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]3532</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3533
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3534<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3535<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3536 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3537
3538<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3539 '<tt>neg</tt>' instruction present in most other intermediate
3540 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3541
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3542<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3543<p>The two arguments to the '<tt>sub</tt>' instruction must
3544 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3545 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3546
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3547<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3548<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3549
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3550<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3551 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3552 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3553
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3554<p>Because LLVM integers use a two's complement representation, this instruction
3555 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3556
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3557<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3558 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3559 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3560 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3561 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3562
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3563<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3564<pre>
3565 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3566 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3567</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3568
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3569</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3570
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3571<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3572<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3573 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3574</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3575
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3576<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3577
3578<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3579<pre>
3580 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3581</pre>
3582
3583<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3584<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3585 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3586
3587<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3588 '<tt>fneg</tt>' instruction present in most other intermediate
3589 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3590
3591<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3592<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3593 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3594 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3595
3596<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3597<p>The value produced is the floating point difference of the two operands.</p>
3598
3599<h5>Example:</h5>
3600<pre>
3601 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3602 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3603</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3604
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3605</div>
3606
3607<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3608<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3609 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3610</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3611
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3612<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3613
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3614<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3615<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3616 &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]3617 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3618 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3619 &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]3620</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3621
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3622<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3623<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3624
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3625<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3626<p>The two arguments to the '<tt>mul</tt>' instruction must
3627 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3628 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3629
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3630<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3631<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3632
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3633<p>If the result of the multiplication has unsigned overflow, the result
3634 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3635 width of the result.</p>
3636
3637<p>Because LLVM integers use a two's complement representation, and the result
3638 is the same width as the operands, this instruction returns the correct
3639 result for both signed and unsigned integers. If a full product
3640 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3641 be sign-extended or zero-extended as appropriate to the width of the full
3642 product.</p>
3643
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3644<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3645 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3646 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3647 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3648 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3649
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3650<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3651<pre>
3652 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3653</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3654
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3655</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3656
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3657<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3658<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3659 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3660</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3661
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3662<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3663
3664<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3665<pre>
3666 &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]3667</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3668
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3669<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3670<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3671
3672<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3673<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3674 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3675 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3676
3677<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3678<p>The value produced is the floating point product of the two operands.</p>
3679
3680<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3681<pre>
3682 &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]3683</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3684
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3685</div>
3686
3687<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3688<h4>
3689 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3690</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3691
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3692<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3693
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3694<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3695<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3696 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3697 &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]3698</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3699
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3700<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3701<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3702
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3703<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3704<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3705 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3706 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3707
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3708<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3709<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3710
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3711<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3712 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3713
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3714<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3715
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3716<p>If the <tt>exact</tt> keyword is present, the result value of the
3717 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3718 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3719
3720
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3721<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3722<pre>
3723 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3724</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3725
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3726</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3727
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3728<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3729<h4>
3730 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3731</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3732
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3733<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3734
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3735<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3736<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3737 &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]3738 &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]3739</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3740
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3741<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3742<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3743
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3744<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3745<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3746 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3747 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3748
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3749<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3750<p>The value produced is the signed integer quotient of the two operands rounded
3751 towards zero.</p>
3752
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3753<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3754 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3755
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3756<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3757 undefined behavior; this is a rare case, but can occur, for example, by doing
3758 a 32-bit division of -2147483648 by -1.</p>
3759
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3760<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3761 <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]3762 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3763
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3764<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3765<pre>
3766 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3767</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3768
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3769</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3770
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3771<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3772<h4>
3773 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3774</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3775
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3776<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3777
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3778<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3779<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3780 &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]3781</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3782
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3783<h5>Overview:</h5>
3784<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3785
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3786<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3787<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3788 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3789 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3790
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3791<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3792<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3793
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3794<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3795<pre>
3796 &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]3797</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3798
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3799</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3800
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3801<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3802<h4>
3803 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3804</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3805
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3806<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3807
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3808<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3809<pre>
3810 &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]3811</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3812
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3813<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3814<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3815 division of its two arguments.</p>
3816
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3817<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3818<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3819 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3820 values. Both arguments must have identical types.</p>
3821
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3822<h5>Semantics:</h5>
3823<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3824 This instruction always performs an unsigned division to get the
3825 remainder.</p>
3826
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3827<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3828 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3829
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3830<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3831
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3832<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3833<pre>
3834 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3835</pre>
3836
3837</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3838
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3839<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3840<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3841 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3842</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3843
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3844<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3845
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3846<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3847<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3848 &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]3849</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3850
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3851<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3852<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3853 division of its two operands. This instruction can also take
3854 <a href="#t_vector">vector</a> versions of the values in which case the
3855 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3856
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3857<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3858<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3859 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3860 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3861
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3862<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3863<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3864 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3865 <i>modulo</i> operator (where the result is either zero or has the same sign
3866 as the divisor, <tt>op2</tt>) of a value.
3867 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3868 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3869 Math Forum</a>. For a table of how this is implemented in various languages,
3870 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3871 Wikipedia: modulo operation</a>.</p>
3872
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3873<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3874 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3875
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3876<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3877 Overflow also leads to undefined behavior; this is a rare case, but can
3878 occur, for example, by taking the remainder of a 32-bit division of
3879 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3880 lets srem be implemented using instructions that return both the result of
3881 the division and the remainder.)</p>
3882
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3883<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3884<pre>
3885 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3886</pre>
3887
3888</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3889
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3890<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3891<h4>
3892 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3893</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3894
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3895<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3896
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3897<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3898<pre>
3899 &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]3900</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3901
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3902<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3903<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3904 its two operands.</p>
3905
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3906<h5>Arguments:</h5>
3907<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3908 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3909 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3910
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3911<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3912<p>This instruction returns the <i>remainder</i> of a division. The remainder
3913 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3914
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3915<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3916<pre>
3917 &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]3918</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3919
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3920</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3921
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3922</div>
3923
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3924<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3925<h3>
3926 <a name="bitwiseops">Bitwise Binary Operations</a>
3927</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3928
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3929<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3930
3931<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3932 program. They are generally very efficient instructions and can commonly be
3933 strength reduced from other instructions. They require two operands of the
3934 same type, execute an operation on them, and produce a single value. The
3935 resulting value is the same type as its operands.</p>
3936
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3937<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3938<h4>
3939 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3940</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3941
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3942<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3943
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3944<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3945<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3946 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3947 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3948 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3949 &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]3950</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3951
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3952<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3953<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3954 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3955
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3956<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3957<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3958 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3959 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3960
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3961<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3962<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3963 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3964 is (statically or dynamically) negative or equal to or larger than the number
3965 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3966 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3967 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3968
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3969<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3970 <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]3971 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3972 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3973 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3974 they would if the shift were expressed as a mul instruction with the same
3975 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3976
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3977<h5>Example:</h5>
3978<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3979 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3980 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3981 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3982 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3983 &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]3984</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3985
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3986</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3987
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3988<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3989<h4>
3990 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3991</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3992
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3993<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3994
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3995<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3996<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3997 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3998 &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]3999</pre>
4000
4001<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4002<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
4003 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4004
4005<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4006<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4007 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4008 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4009
4010<h5>Semantics:</h5>
4011<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4012 significant bits of the result will be filled with zero bits after the shift.
4013 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
4014 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4015 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4016 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4017
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4018<p>If the <tt>exact</tt> keyword is present, the result value of the
4019 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4020 shifted out are non-zero.</p>
4021
4022
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4023<h5>Example:</h5>
4024<pre>
4025 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4026 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4027 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4028 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4029 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4030 &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]4031</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4032
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4033</div>
4034
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]4035<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4036<h4>
4037 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4038</h4>
4039
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4040<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4041
4042<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4043<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4044 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4045 &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]4046</pre>
4047
4048<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4049<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4050 operand shifted to the right a specified number of bits with sign
4051 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4052
4053<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4054<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4055 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4056 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4057
4058<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4059<p>This instruction always performs an arithmetic shift right operation, The
4060 most significant bits of the result will be filled with the sign bit
4061 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4062 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4063 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4064 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4065
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4066<p>If the <tt>exact</tt> keyword is present, the result value of the
4067 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4068 shifted out are non-zero.</p>
4069
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4070<h5>Example:</h5>
4071<pre>
4072 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4073 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4074 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4075 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4076 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4077 &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]4078</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4079
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4080</div>
4081
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4082<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4083<h4>
4084 <a name="i_and">'<tt>and</tt>' Instruction</a>
4085</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4086
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4087<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4088
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4089<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4090<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4091 &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]4092</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4093
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4094<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4095<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4096 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4097
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4098<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4099<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4100 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4101 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4102
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4103<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4104<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4105
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4106<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4107 <tbody>
4108 <tr>
4109 <td>In0</td>
4110 <td>In1</td>
4111 <td>Out</td>
4112 </tr>
4113 <tr>
4114 <td>0</td>
4115 <td>0</td>
4116 <td>0</td>
4117 </tr>
4118 <tr>
4119 <td>0</td>
4120 <td>1</td>
4121 <td>0</td>
4122 </tr>
4123 <tr>
4124 <td>1</td>
4125 <td>0</td>
4126 <td>0</td>
4127 </tr>
4128 <tr>
4129 <td>1</td>
4130 <td>1</td>
4131 <td>1</td>
4132 </tr>
4133 </tbody>
4134</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4135
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4136<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4137<pre>
4138 &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]4139 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4140 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4141</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4142</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4143<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4144<h4>
4145 <a name="i_or">'<tt>or</tt>' Instruction</a>
4146</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4147
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4148<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4149
4150<h5>Syntax:</h5>
4151<pre>
4152 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4153</pre>
4154
4155<h5>Overview:</h5>
4156<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4157 two operands.</p>
4158
4159<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4160<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4161 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4162 values. Both arguments must have identical types.</p>
4163
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4164<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4165<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4166
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4167<table border="1" cellspacing="0" cellpadding="4">
4168 <tbody>
4169 <tr>
4170 <td>In0</td>
4171 <td>In1</td>
4172 <td>Out</td>
4173 </tr>
4174 <tr>
4175 <td>0</td>
4176 <td>0</td>
4177 <td>0</td>
4178 </tr>
4179 <tr>
4180 <td>0</td>
4181 <td>1</td>
4182 <td>1</td>
4183 </tr>
4184 <tr>
4185 <td>1</td>
4186 <td>0</td>
4187 <td>1</td>
4188 </tr>
4189 <tr>
4190 <td>1</td>
4191 <td>1</td>
4192 <td>1</td>
4193 </tr>
4194 </tbody>
4195</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4196
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4197<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4198<pre>
4199 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4200 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4201 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4202</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4203
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4204</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4205
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4206<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4207<h4>
4208 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4209</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4210
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4211<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4212
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4213<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4214<pre>
4215 &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]4216</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4217
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4218<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4219<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4220 its two operands. The <tt>xor</tt> is used to implement the "one's
4221 complement" operation, which is the "~" operator in C.</p>
4222
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4223<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4224<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4225 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4226 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4227
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4228<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4229<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4230
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4231<table border="1" cellspacing="0" cellpadding="4">
4232 <tbody>
4233 <tr>
4234 <td>In0</td>
4235 <td>In1</td>
4236 <td>Out</td>
4237 </tr>
4238 <tr>
4239 <td>0</td>
4240 <td>0</td>
4241 <td>0</td>
4242 </tr>
4243 <tr>
4244 <td>0</td>
4245 <td>1</td>
4246 <td>1</td>
4247 </tr>
4248 <tr>
4249 <td>1</td>
4250 <td>0</td>
4251 <td>1</td>
4252 </tr>
4253 <tr>
4254 <td>1</td>
4255 <td>1</td>
4256 <td>0</td>
4257 </tr>
4258 </tbody>
4259</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4260
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4261<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4262<pre>
4263 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4264 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4265 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4266 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4267</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4268
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4269</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4271</div>
4272
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4273<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4274<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4275 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4276</h3>
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<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4281 target-independent manner. These instructions cover the element-access and
4282 vector-specific operations needed to process vectors effectively. While LLVM
4283 does directly support these vector operations, many sophisticated algorithms
4284 will want to use target-specific intrinsics to take full advantage of a
4285 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4286
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4287<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4288<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4289 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4290</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4291
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4292<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4293
4294<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4295<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4296 &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]4297</pre>
4298
4299<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4300<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4301 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4302
4303
4304<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4305<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4306 of <a href="#t_vector">vector</a> type. The second operand is an index
4307 indicating the position from which to extract the element. The index may be
4308 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4309
4310<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4311<p>The result is a scalar of the same type as the element type of
4312 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4313 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4314 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4315
4316<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4317<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4318 &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]4319</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4320
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4321</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4322
4323<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4324<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4325 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4326</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4327
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4328<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4329
4330<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4331<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4332 &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]4333</pre>
4334
4335<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4336<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4337 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4338
4339<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4340<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4341 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4342 whose type must equal the element type of the first operand. The third
4343 operand is an index indicating the position at which to insert the value.
4344 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4345
4346<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4347<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4348 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4349 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4350 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4351
4352<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4353<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4354 &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]4355</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4356
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4357</div>
4358
4359<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4360<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4361 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4362</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4363
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4364<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4365
4366<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4367<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4368 &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]4369</pre>
4370
4371<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4372<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4373 from two input vectors, returning a vector with the same element type as the
4374 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4375
4376<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4377<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4378 with types that match each other. The third argument is a shuffle mask whose
4379 element type is always 'i32'. The result of the instruction is a vector
4380 whose length is the same as the shuffle mask and whose element type is the
4381 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4382
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4383<p>The shuffle mask operand is required to be a constant vector with either
4384 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4385
4386<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4387<p>The elements of the two input vectors are numbered from left to right across
4388 both of the vectors. The shuffle mask operand specifies, for each element of
4389 the result vector, which element of the two input vectors the result element
4390 gets. The element selector may be undef (meaning "don't care") and the
4391 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4392
4393<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4394<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4395 &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]4396 &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]4397 &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]4398 &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]4399 &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]4400 &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]4401 &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]4402 &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]4403</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4404
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4405</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4406
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4407</div>
4408
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4409<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4410<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4411 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4412</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4413
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4414<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4415
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4416<p>LLVM supports several instructions for working with
4417 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4418
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4419<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4420<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4421 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4422</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4423
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4424<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4425
4426<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4427<pre>
4428 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4429</pre>
4430
4431<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4432<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4433 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4434
4435<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4436<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4437 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4438 <a href="#t_array">array</a> type. The operands are constant indices to
4439 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4440 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4441 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4442 <ul>
4443 <li>Since the value being indexed is not a pointer, the first index is
4444 omitted and assumed to be zero.</li>
4445 <li>At least one index must be specified.</li>
4446 <li>Not only struct indices but also array indices must be in
4447 bounds.</li>
4448 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4449
4450<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4451<p>The result is the value at the position in the aggregate specified by the
4452 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4453
4454<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4455<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4456 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4457</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4458
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4459</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4460
4461<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4462<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4463 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4464</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4465
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4466<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4467
4468<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4469<pre>
Bill Wendlingf6a91cf2011-07-26 20:42:28 +0000[diff] [blame]4470 &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]4471</pre>
4472
4473<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4474<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4475 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4476
4477<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4478<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4479 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4480 <a href="#t_array">array</a> type. The second operand is a first-class
4481 value to insert. The following operands are constant indices indicating
4482 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]4483 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4484 value to insert must have the same type as the value identified by the
4485 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4486
4487<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4488<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4489 that of <tt>val</tt> except that the value at the position specified by the
4490 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4491
4492<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4493<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4494 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4495 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4496 %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]4497</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4498
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4499</div>
4500
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4501</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4502
4503<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4504<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4505 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4506</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4507
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4508<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4509
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4510<p>A key design point of an SSA-based representation is how it represents
4511 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4512 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4513 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4514
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4515<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4516<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4517 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4518</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4519
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4520<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4521
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4522<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4523<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4524 &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]4525</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4526
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4527<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4528<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4529 currently executing function, to be automatically released when this function
4530 returns to its caller. The object is always allocated in the generic address
4531 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4532
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4533<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4534<p>The '<tt>alloca</tt>' instruction
4535 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4536 runtime stack, returning a pointer of the appropriate type to the program.
4537 If "NumElements" is specified, it is the number of elements allocated,
4538 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4539 specified, the value result of the allocation is guaranteed to be aligned to
4540 at least that boundary. If not specified, or if zero, the target can choose
4541 to align the allocation on any convenient boundary compatible with the
4542 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4543
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4544<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4545
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4546<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4547<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4548 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4549 memory is automatically released when the function returns. The
4550 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4551 variables that must have an address available. When the function returns
4552 (either with the <tt><a href="#i_ret">ret</a></tt>
4553 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4554 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4555
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4556<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4557<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4558 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4559 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4560 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4561 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4562</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4563
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4564</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4565
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4566<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4567<h4>
4568 <a name="i_load">'<tt>load</tt>' Instruction</a>
4569</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4570
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4571<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4572
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4573<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4574<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4575 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4576 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4577 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4578</pre>
4579
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4580<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4581<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4582
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4583<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4584<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4585 from which to load. The pointer must point to
4586 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4587 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4588 number or order of execution of this <tt>load</tt> with other <a
4589 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4590
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4591<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4592 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]4593 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4594 alignment for the target. It is the responsibility of the code emitter to
4595 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4596 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4597 produce less efficient code. An alignment of 1 is always safe.</p>
4598
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4599<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4600 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4601 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4602 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4603 and code generator that this load is not expected to be reused in the cache.
4604 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4605 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4606
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4607<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4608<p>The location of memory pointed to is loaded. If the value being loaded is of
4609 scalar type then the number of bytes read does not exceed the minimum number
4610 of bytes needed to hold all bits of the type. For example, loading an
4611 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4612 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4613 is undefined if the value was not originally written using a store of the
4614 same type.</p>
4615
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4616<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4617<pre>
4618 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4619 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4620 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4621</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4622
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4623</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4624
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4625<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4626<h4>
4627 <a name="i_store">'<tt>store</tt>' Instruction</a>
4628</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4629
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4630<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4631
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4632<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4633<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4634 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>
4635 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]4636</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4637
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4638<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4639<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4640
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4641<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4642<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4643 and an address at which to store it. The type of the
4644 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4645 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4646 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4647 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4648 order of execution of this <tt>store</tt> with other <a
4649 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4650
4651<p>The optional constant "align" argument specifies the alignment of the
4652 operation (that is, the alignment of the memory address). A value of 0 or an
4653 omitted "align" argument means that the operation has the preferential
4654 alignment for the target. It is the responsibility of the code emitter to
4655 ensure that the alignment information is correct. Overestimating the
4656 alignment results in an undefined behavior. Underestimating the alignment may
4657 produce less efficient code. An alignment of 1 is always safe.</p>
4658
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4659<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4660 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4661 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4662 instruction tells the optimizer and code generator that this load is
4663 not expected to be reused in the cache. The code generator may
4664 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4665 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4666
4667
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4668<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4669<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4670 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4671 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4672 does not exceed the minimum number of bytes needed to hold all bits of the
4673 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4674 writing a value of a type like <tt>i20</tt> with a size that is not an
4675 integral number of bytes, it is unspecified what happens to the extra bits
4676 that do not belong to the type, but they will typically be overwritten.</p>
4677
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4678<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4679<pre>
4680 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4681 store i32 3, i32* %ptr <i>; yields {void}</i>
4682 %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]4683</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4684
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4685</div>
4686
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4687<!-- _______________________________________________________________________ -->
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]4688<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4689Instruction</a> </div>
4690
4691<div class="doc_text">
4692
4693<h5>Syntax:</h5>
4694<pre>
4695 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4696</pre>
4697
4698<h5>Overview:</h5>
4699<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4700between operations.</p>
4701
4702<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4703href="#ordering">ordering</a> argument which defines what
4704<i>synchronizes-with</i> edges they add. They can only be given
4705<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4706<code>seq_cst</code> orderings.</p>
4707
4708<h5>Semantics:</h5>
4709<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4710semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4711<code>acquire</code> ordering semantics if and only if there exist atomic
4712operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4713<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4714<var>X</var> modifies <var>M</var> (either directly or through some side effect
4715of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4716<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4717<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4718than an explicit <code>fence</code>, one (but not both) of the atomic operations
4719<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4720<code>acquire</code> (resp.) ordering constraint and still
4721<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4722<i>happens-before</i> edge.</p>
4723
4724<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4725having both <code>acquire</code> and <code>release</code> semantics specified
4726above, participates in the global program order of other <code>seq_cst</code>
4727operations and/or fences.</p>
4728
4729<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4730specifies that the fence only synchronizes with other fences in the same
4731thread. (This is useful for interacting with signal handlers.)</p>
4732
4733<p>FIXME: This instruction is a work in progress; until it is finished, use
4734 llvm.memory.barrier.
4735
4736<h5>Example:</h5>
4737<pre>
4738 fence acquire <i>; yields {void}</i>
4739 fence singlethread seq_cst <i>; yields {void}</i>
4740</pre>
4741
4742</div>
4743
4744<!-- _______________________________________________________________________ -->
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]4745<div class="doc_subsubsection"> <a name="i_cmpxchg">'<tt>cmpxchg</tt>'
4746Instruction</a> </div>
4747
4748<div class="doc_text">
4749
4750<h5>Syntax:</h5>
4751<pre>
4752 [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>
4753</pre>
4754
4755<h5>Overview:</h5>
4756<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4757It loads a value in memory and compares it to a given value. If they are
4758equal, it stores a new value into the memory.</p>
4759
4760<h5>Arguments:</h5>
4761<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4762address to operate on, a value to compare to the value currently be at that
4763address, and a new value to place at that address if the compared values are
4764equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4765bit width is a power of two greater than or equal to eight and less than
4766or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4767'<var>&lt;new&gt;</var>' must have the same type, and the type of
4768'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4769<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4770optimizer is not allowed to modify the number or order of execution
4771of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4772operations</a>.</p>
4773
4774<!-- FIXME: Extend allowed types. -->
4775
4776<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4777<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4778
4779<p>The optional "<code>singlethread</code>" argument declares that the
4780<code>cmpxchg</code> is only atomic with respect to code (usually signal
4781handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4782cmpxchg is atomic with respect to all other code in the system.</p>
4783
4784<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4785the size in memory of the operand.
4786
4787<h5>Semantics:</h5>
4788<p>The contents of memory at the location specified by the
4789'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4790'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4791'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4792is returned.
4793
4794<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4795purpose of identifying <a href="#release_sequence">release sequences</a>. A
4796failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4797parameter determined by dropping any <code>release</code> part of the
4798<code>cmpxchg</code>'s ordering.</p>
4799
4800<!--
4801FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4802optimization work on ARM.)
4803
4804FIXME: Is a weaker ordering constraint on failure helpful in practice?
4805-->
4806
4807<h5>Example:</h5>
4808<pre>
4809entry:
4810 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4811 <a href="#i_br">br</a> label %loop
4812
4813loop:
4814 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4815 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4816 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4817 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4818 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4819
4820done:
4821 ...
4822</pre>
4823
4824</div>
4825
4826<!-- _______________________________________________________________________ -->
4827<div class="doc_subsubsection"> <a name="i_atomicrmw">'<tt>atomicrmw</tt>'
4828Instruction</a> </div>
4829
4830<div class="doc_text">
4831
4832<h5>Syntax:</h5>
4833<pre>
4834 [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>
4835</pre>
4836
4837<h5>Overview:</h5>
4838<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4839
4840<h5>Arguments:</h5>
4841<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4842operation to apply, an address whose value to modify, an argument to the
4843operation. The operation must be one of the following keywords:</p>
4844<ul>
4845 <li>xchg</li>
4846 <li>add</li>
4847 <li>sub</li>
4848 <li>and</li>
4849 <li>nand</li>
4850 <li>or</li>
4851 <li>xor</li>
4852 <li>max</li>
4853 <li>min</li>
4854 <li>umax</li>
4855 <li>umin</li>
4856</ul>
4857
4858<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4859bit width is a power of two greater than or equal to eight and less than
4860or equal to a target-specific size limit. The type of the
4861'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4862If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4863optimizer is not allowed to modify the number or order of execution of this
4864<code>atomicrmw</code> with other <a href="#volatile">volatile
4865 operations</a>.</p>
4866
4867<!-- FIXME: Extend allowed types. -->
4868
4869<h5>Semantics:</h5>
4870<p>The contents of memory at the location specified by the
4871'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4872back. The original value at the location is returned. The modification is
4873specified by the <var>operation</var> argument:</p>
4874
4875<ul>
4876 <li>xchg: <code>*ptr = val</code></li>
4877 <li>add: <code>*ptr = *ptr + val</code></li>
4878 <li>sub: <code>*ptr = *ptr - val</code></li>
4879 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4880 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4881 <li>or: <code>*ptr = *ptr | val</code></li>
4882 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4883 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4884 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4885 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4886 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4887</ul>
4888
4889<h5>Example:</h5>
4890<pre>
4891 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4892</pre>
4893
4894</div>
4895
4896<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4897<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4898 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4899</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4900
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4901<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4902
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4903<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4904<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4905 &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]4906 &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]4907</pre>
4908
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4909<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4910<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4911 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4912 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4913
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4914<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4915<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4916 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4917 elements of the aggregate object are indexed. The interpretation of each
4918 index is dependent on the type being indexed into. The first index always
4919 indexes the pointer value given as the first argument, the second index
4920 indexes a value of the type pointed to (not necessarily the value directly
4921 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4922 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4923 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4924 can never be pointers, since that would require loading the pointer before
4925 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4926
4927<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]4928 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4929 integer <b>constants</b> are allowed. When indexing into an array, pointer
4930 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]4931 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4932
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4933<p>For example, let's consider a C code fragment and how it gets compiled to
4934 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4935
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4936<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4937struct RT {
4938 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4939 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4940 char C;
4941};
4942struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4943 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4944 double Y;
4945 struct RT Z;
4946};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4947
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4948int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4949 return &amp;s[1].Z.B[5][13];
4950}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4951</pre>
4952
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4953<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4954
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4955<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4956%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4957%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4958
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4959define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4960entry:
4961 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4962 ret i32* %reg
4963}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4964</pre>
4965
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4966<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4967<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]4968 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4969 }</tt>' type, a structure. The second index indexes into the third element
4970 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4971 i8 }</tt>' type, another structure. The third index indexes into the second
4972 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4973 array. The two dimensions of the array are subscripted into, yielding an
4974 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4975 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4976
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4977<p>Note that it is perfectly legal to index partially through a structure,
4978 returning a pointer to an inner element. Because of this, the LLVM code for
4979 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4980
4981<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4982 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4983 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4984 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4985 %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]4986 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4987 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4988 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4989 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4990</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4991
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4992<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4993 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4994 base pointer is not an <i>in bounds</i> address of an allocated object,
4995 or if any of the addresses that would be formed by successive addition of
4996 the offsets implied by the indices to the base address with infinitely
4997 precise arithmetic are not an <i>in bounds</i> address of that allocated
4998 object. The <i>in bounds</i> addresses for an allocated object are all
4999 the addresses that point into the object, plus the address one byte past
5000 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]5001
5002<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
5003 the base address with silently-wrapping two's complement arithmetic, and
5004 the result value of the <tt>getelementptr</tt> may be outside the object
5005 pointed to by the base pointer. The result value may not necessarily be
5006 used to access memory though, even if it happens to point into allocated
5007 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
5008 section for more information.</p>
5009
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5010<p>The getelementptr instruction is often confusing. For some more insight into
5011 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]5012
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]5013<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5014<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5015 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]5016 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
5017 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5018 %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]5019 <i>; yields i8*:eptr</i>
5020 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]5021 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]5022 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5023</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5024
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5025</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]5026
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5027</div>
5028
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5029<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5030<h3>
5031 <a name="convertops">Conversion Operations</a>
5032</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5033
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5034<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5035
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5036<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5037 which all take a single operand and a type. They perform various bit
5038 conversions on the operand.</p>
5039
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5040<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5041<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5042 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5043</h4>
5044
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5045<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5046
5047<h5>Syntax:</h5>
5048<pre>
5049 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5050</pre>
5051
5052<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5053<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5054 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5055
5056<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5057<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5058 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5059 of the same number of integers.
5060 The bit size of the <tt>value</tt> must be larger than
5061 the bit size of the destination type, <tt>ty2</tt>.
5062 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5063
5064<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5065<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5066 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5067 source size must be larger than the destination size, <tt>trunc</tt> cannot
5068 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5069
5070<h5>Example:</h5>
5071<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5072 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5073 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5074 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5075 %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]5076</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5077
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5078</div>
5079
5080<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5081<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5082 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5083</h4>
5084
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5085<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5086
5087<h5>Syntax:</h5>
5088<pre>
5089 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5090</pre>
5091
5092<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5093<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5094 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5095
5096
5097<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5098<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5099 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5100 of the same number of integers.
5101 The bit size of the <tt>value</tt> must be smaller than
5102 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5103 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5104
5105<h5>Semantics:</h5>
5106<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]5107 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5108
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]5109<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]5110
5111<h5>Example:</h5>
5112<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5113 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5114 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5115 %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]5116</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5117
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5118</div>
5119
5120<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5121<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5122 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5123</h4>
5124
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5125<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5126
5127<h5>Syntax:</h5>
5128<pre>
5129 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5130</pre>
5131
5132<h5>Overview:</h5>
5133<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5134
5135<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5136<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5137 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5138 of the same number of integers.
5139 The bit size of the <tt>value</tt> must be smaller than
5140 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5141 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5142
5143<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5144<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5145 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5146 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5147
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5148<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]5149
5150<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5151<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5152 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5153 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5154 %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]5155</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5156
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5157</div>
5158
5159<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5160<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5161 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5162</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5163
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5164<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5165
5166<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5167<pre>
5168 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5169</pre>
5170
5171<h5>Overview:</h5>
5172<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5173 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5174
5175<h5>Arguments:</h5>
5176<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5177 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5178 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]5179 <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]5180 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5181
5182<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5183<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5184 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5185 <a href="#t_floating">floating point</a> type. If the value cannot fit
5186 within the destination type, <tt>ty2</tt>, then the results are
5187 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5188
5189<h5>Example:</h5>
5190<pre>
5191 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5192 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5193</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5194
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5195</div>
5196
5197<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5198<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5199 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5200</h4>
5201
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5202<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5203
5204<h5>Syntax:</h5>
5205<pre>
5206 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5207</pre>
5208
5209<h5>Overview:</h5>
5210<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]5211 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5212
5213<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5214<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5215 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5216 a <a href="#t_floating">floating point</a> type to cast it to. The source
5217 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5218
5219<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5220<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5221 <a href="#t_floating">floating point</a> type to a larger
5222 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5223 used to make a <i>no-op cast</i> because it always changes bits. Use
5224 <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]5225
5226<h5>Example:</h5>
5227<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]5228 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5229 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5230</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5231
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5232</div>
5233
5234<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5235<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]5236 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5237</h4>
5238
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5239<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5240
5241<h5>Syntax:</h5>
5242<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5243 &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]5244</pre>
5245
5246<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5247<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5248 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5249
5250<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5251<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5252 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5253 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5254 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5255 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5256
5257<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5258<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5259 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5260 towards zero) unsigned integer value. If the value cannot fit
5261 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5262
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5263<h5>Example:</h5>
5264<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5265 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5266 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5267 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5268</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5269
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5270</div>
5271
5272<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5273<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5274 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5275</h4>
5276
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5277<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5278
5279<h5>Syntax:</h5>
5280<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5281 &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]5282</pre>
5283
5284<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5285<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5286 <a href="#t_floating">floating point</a> <tt>value</tt> to
5287 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5288
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5289<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5290<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5291 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5292 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5293 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5294 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5295
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5296<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5297<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5298 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5299 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5300 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5301
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5302<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5303<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5304 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5305 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5306 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5307</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5308
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5309</div>
5310
5311<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5312<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5313 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5314</h4>
5315
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5316<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5317
5318<h5>Syntax:</h5>
5319<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5320 &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]5321</pre>
5322
5323<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5324<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5325 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5326
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5327<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5328<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]5329 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5330 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5331 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5332 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5333
5334<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5335<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5336 integer quantity and converts it to the corresponding floating point
5337 value. If the value cannot fit in the floating point value, the results are
5338 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5339
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5340<h5>Example:</h5>
5341<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5342 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5343 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5344</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5345
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5346</div>
5347
5348<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5349<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5350 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5351</h4>
5352
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5353<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5354
5355<h5>Syntax:</h5>
5356<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5357 &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]5358</pre>
5359
5360<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5361<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5362 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5363
5364<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5365<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]5366 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5367 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5368 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5369 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5370
5371<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5372<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5373 quantity and converts it to the corresponding floating point value. If the
5374 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5375
5376<h5>Example:</h5>
5377<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5378 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5379 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5380</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5381
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5382</div>
5383
5384<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5385<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5386 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5387</h4>
5388
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5389<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5390
5391<h5>Syntax:</h5>
5392<pre>
5393 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5394</pre>
5395
5396<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5397<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5398 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5399
5400<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5401<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5402 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5403 <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]5404
5405<h5>Semantics:</h5>
5406<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5407 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5408 truncating or zero extending that value to the size of the integer type. If
5409 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5410 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5411 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5412 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5413
5414<h5>Example:</h5>
5415<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5416 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5417 %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]5418</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5419
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5420</div>
5421
5422<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5423<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5424 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5425</h4>
5426
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5427<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5428
5429<h5>Syntax:</h5>
5430<pre>
5431 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5432</pre>
5433
5434<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5435<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5436 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5437
5438<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5439<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5440 value to cast, and a type to cast it to, which must be a
5441 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5442
5443<h5>Semantics:</h5>
5444<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5445 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5446 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5447 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5448 than the size of a pointer then a zero extension is done. If they are the
5449 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5450
5451<h5>Example:</h5>
5452<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5453 %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]5454 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5455 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5456</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5457
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5458</div>
5459
5460<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5461<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5462 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5463</h4>
5464
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5465<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5466
5467<h5>Syntax:</h5>
5468<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5469 &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]5470</pre>
5471
5472<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5473<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5474 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5475
5476<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5477<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5478 non-aggregate first class value, and a type to cast it to, which must also be
5479 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5480 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5481 identical. If the source type is a pointer, the destination type must also be
5482 a pointer. This instruction supports bitwise conversion of vectors to
5483 integers and to vectors of other types (as long as they have the same
5484 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5485
5486<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5487<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5488 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5489 this conversion. The conversion is done as if the <tt>value</tt> had been
5490 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5491 be converted to other pointer types with this instruction. To convert
5492 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5493 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5494
5495<h5>Example:</h5>
5496<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5497 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5498 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5499 %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]5500</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5501
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5502</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5503
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5504</div>
5505
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5506<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5507<h3>
5508 <a name="otherops">Other Operations</a>
5509</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5510
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5511<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5512
5513<p>The instructions in this category are the "miscellaneous" instructions, which
5514 defy better classification.</p>
5515
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5516<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5517<h4>
5518 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5519</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5520
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5521<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5522
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5523<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5524<pre>
5525 &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]5526</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5527
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5528<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5529<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5530 boolean values based on comparison of its two integer, integer vector, or
5531 pointer operands.</p>
5532
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5533<h5>Arguments:</h5>
5534<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5535 the condition code indicating the kind of comparison to perform. It is not a
5536 value, just a keyword. The possible condition code are:</p>
5537
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5538<ol>
5539 <li><tt>eq</tt>: equal</li>
5540 <li><tt>ne</tt>: not equal </li>
5541 <li><tt>ugt</tt>: unsigned greater than</li>
5542 <li><tt>uge</tt>: unsigned greater or equal</li>
5543 <li><tt>ult</tt>: unsigned less than</li>
5544 <li><tt>ule</tt>: unsigned less or equal</li>
5545 <li><tt>sgt</tt>: signed greater than</li>
5546 <li><tt>sge</tt>: signed greater or equal</li>
5547 <li><tt>slt</tt>: signed less than</li>
5548 <li><tt>sle</tt>: signed less or equal</li>
5549</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5550
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5551<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5552 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5553 typed. They must also be identical types.</p>
5554
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5555<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5556<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5557 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5558 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]5559 result, as follows:</p>
5560
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5561<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5562 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5563 <tt>false</tt> otherwise. No sign interpretation is necessary or
5564 performed.</li>
5565
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5566 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5567 <tt>false</tt> otherwise. No sign interpretation is necessary or
5568 performed.</li>
5569
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5570 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5571 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5572
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5573 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5574 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5575 to <tt>op2</tt>.</li>
5576
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5577 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5578 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5579
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5580 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5581 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5582
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5583 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5584 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5585
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5586 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5587 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5588 to <tt>op2</tt>.</li>
5589
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5590 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5591 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5592
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5593 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5594 <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]5595</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5596
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5597<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5598 values are compared as if they were integers.</p>
5599
5600<p>If the operands are integer vectors, then they are compared element by
5601 element. The result is an <tt>i1</tt> vector with the same number of elements
5602 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5603
5604<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5605<pre>
5606 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5607 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5608 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5609 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5610 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5611 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5612</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5613
5614<p>Note that the code generator does not yet support vector types with
5615 the <tt>icmp</tt> instruction.</p>
5616
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5617</div>
5618
5619<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5620<h4>
5621 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5622</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5623
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5624<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5625
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5626<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5627<pre>
5628 &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]5629</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5630
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5631<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5632<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5633 values based on comparison of its operands.</p>
5634
5635<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]5636(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5637
5638<p>If the operands are floating point vectors, then the result type is a vector
5639 of boolean with the same number of elements as the operands being
5640 compared.</p>
5641
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5642<h5>Arguments:</h5>
5643<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5644 the condition code indicating the kind of comparison to perform. It is not a
5645 value, just a keyword. The possible condition code are:</p>
5646
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5647<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5648 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5649 <li><tt>oeq</tt>: ordered and equal</li>
5650 <li><tt>ogt</tt>: ordered and greater than </li>
5651 <li><tt>oge</tt>: ordered and greater than or equal</li>
5652 <li><tt>olt</tt>: ordered and less than </li>
5653 <li><tt>ole</tt>: ordered and less than or equal</li>
5654 <li><tt>one</tt>: ordered and not equal</li>
5655 <li><tt>ord</tt>: ordered (no nans)</li>
5656 <li><tt>ueq</tt>: unordered or equal</li>
5657 <li><tt>ugt</tt>: unordered or greater than </li>
5658 <li><tt>uge</tt>: unordered or greater than or equal</li>
5659 <li><tt>ult</tt>: unordered or less than </li>
5660 <li><tt>ule</tt>: unordered or less than or equal</li>
5661 <li><tt>une</tt>: unordered or not equal</li>
5662 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5663 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5664</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5665
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5666<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5667 <i>unordered</i> means that either operand may be a QNAN.</p>
5668
5669<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5670 a <a href="#t_floating">floating point</a> type or
5671 a <a href="#t_vector">vector</a> of floating point type. They must have
5672 identical types.</p>
5673
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5674<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5675<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5676 according to the condition code given as <tt>cond</tt>. If the operands are
5677 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5678 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5679 follows:</p>
5680
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5681<ol>
5682 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5683
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5684 <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]5685 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5686
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5687 <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]5688 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5689
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5690 <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]5691 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5692
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5693 <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]5694 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5695
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5696 <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]5697 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5698
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5699 <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]5700 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5701
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5702 <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]5703
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5704 <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]5705 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5706
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5707 <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]5708 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5709
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5710 <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]5711 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5712
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5713 <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]5714 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5715
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5716 <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]5717 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5718
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5719 <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]5720 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5721
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5722 <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]5723
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5724 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5725</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5726
5727<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5728<pre>
5729 &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]5730 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5731 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5732 &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]5733</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5734
5735<p>Note that the code generator does not yet support vector types with
5736 the <tt>fcmp</tt> instruction.</p>
5737
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5738</div>
5739
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5740<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5741<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5742 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5743</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5744
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5745<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5746
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5747<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5748<pre>
5749 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5750</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5751
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5752<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5753<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5754 SSA graph representing the function.</p>
5755
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5756<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5757<p>The type of the incoming values is specified with the first type field. After
5758 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5759 one pair for each predecessor basic block of the current block. Only values
5760 of <a href="#t_firstclass">first class</a> type may be used as the value
5761 arguments to the PHI node. Only labels may be used as the label
5762 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5763
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5764<p>There must be no non-phi instructions between the start of a basic block and
5765 the PHI instructions: i.e. PHI instructions must be first in a basic
5766 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5767
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5768<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5769 occur on the edge from the corresponding predecessor block to the current
5770 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5771 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5772
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5773<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5774<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5775 specified by the pair corresponding to the predecessor basic block that
5776 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5777
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5778<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5779<pre>
5780Loop: ; Infinite loop that counts from 0 on up...
5781 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5782 %nextindvar = add i32 %indvar, 1
5783 br label %Loop
5784</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5785
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5786</div>
5787
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5788<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5789<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5790 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5791</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5792
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5793<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5794
5795<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5796<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5797 &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>
5798
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5799 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5800</pre>
5801
5802<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5803<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5804 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5805
5806
5807<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5808<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5809 values indicating the condition, and two values of the
5810 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5811 vectors and the condition is a scalar, then entire vectors are selected, not
5812 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5813
5814<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5815<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5816 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5817
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5818<p>If the condition is a vector of i1, then the value arguments must be vectors
5819 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5820
5821<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5822<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5823 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5824</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5825
5826<p>Note that the code generator does not yet support conditions
5827 with vector type.</p>
5828
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5829</div>
5830
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5831<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5832<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5833 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5834</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5835
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5836<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5837
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5838<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5839<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5840 &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]5841</pre>
5842
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5843<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5844<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5845
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5846<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5847<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5848
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5849<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5850 <li>The optional "tail" marker indicates that the callee function does not
5851 access any allocas or varargs in the caller. Note that calls may be
5852 marked "tail" even if they do not occur before
5853 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5854 present, the function call is eligible for tail call optimization,
5855 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5856 optimized into a jump</a>. The code generator may optimize calls marked
5857 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5858 sibling call optimization</a> when the caller and callee have
5859 matching signatures, or 2) forced tail call optimization when the
5860 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5861 <ul>
5862 <li>Caller and callee both have the calling
5863 convention <tt>fastcc</tt>.</li>
5864 <li>The call is in tail position (ret immediately follows call and ret
5865 uses value of call or is void).</li>
5866 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5867 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5868 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5869 constraints are met.</a></li>
5870 </ul>
5871 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5872
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5873 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5874 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5875 defaults to using C calling conventions. The calling convention of the
5876 call must match the calling convention of the target function, or else the
5877 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5878
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5879 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5880 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5881 '<tt>inreg</tt>' attributes are valid here.</li>
5882
5883 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5884 type of the return value. Functions that return no value are marked
5885 <tt><a href="#t_void">void</a></tt>.</li>
5886
5887 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5888 being invoked. The argument types must match the types implied by this
5889 signature. This type can be omitted if the function is not varargs and if
5890 the function type does not return a pointer to a function.</li>
5891
5892 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5893 be invoked. In most cases, this is a direct function invocation, but
5894 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5895 to function value.</li>
5896
5897 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5898 signature argument types and parameter attributes. All arguments must be
5899 of <a href="#t_firstclass">first class</a> type. If the function
5900 signature indicates the function accepts a variable number of arguments,
5901 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5902
5903 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5904 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5905 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5906</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5907
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5908<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5909<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5910 a specified function, with its incoming arguments bound to the specified
5911 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5912 function, control flow continues with the instruction after the function
5913 call, and the return value of the function is bound to the result
5914 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5915
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5916<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5917<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5918 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5919 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5920 %X = tail call i32 @foo() <i>; yields i32</i>
5921 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5922 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5923
5924 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5925 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5926 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5927 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5928 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5929 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5930</pre>
5931
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5932<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5933standard C99 library as being the C99 library functions, and may perform
5934optimizations or generate code for them under that assumption. This is
5935something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5936freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5937
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5938</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5939
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5940<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5941<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5942 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5943</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5944
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5945<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5946
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5947<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5948<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5949 &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]5950</pre>
5951
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5952<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5953<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5954 the "variable argument" area of a function call. It is used to implement the
5955 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5956
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5957<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5958<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5959 argument. It returns a value of the specified argument type and increments
5960 the <tt>va_list</tt> to point to the next argument. The actual type
5961 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5962
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5963<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5964<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5965 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5966 to the next argument. For more information, see the variable argument
5967 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5968
5969<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]5970 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5971 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5972
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5973<p><tt>va_arg</tt> is an LLVM instruction instead of
5974 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5975 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5976
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5977<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5978<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5979
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5980<p>Note that the code generator does not yet fully support va_arg on many
5981 targets. Also, it does not currently support va_arg with aggregate types on
5982 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5983
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5984</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5985
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]5986<!-- _______________________________________________________________________ -->
5987<h4>
5988 <a name="i_landingpad">'<tt>landingpad</tt>' Instruction</a>
5989</h4>
5990
5991<div>
5992
5993<h5>Syntax:</h5>
5994<pre>
Bill Wendling49bfb122011-08-08 08:06:05 +0000[diff] [blame^]5995 &lt;resultval&gt; = landingpad &lt;somety&gt; personality &lt;type&gt; &lt;pers_fn&gt; &lt;clause&gt;+
5996 &lt;resultval&gt; = landingpad &lt;somety&gt; personality &lt;type&gt; &lt;pers_fn&gt; cleanup &lt;clause&gt;*
5997
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]5998 &lt;clause&gt; := catch &lt;type&gt; &lt;value&gt;
Bill Wendling49bfb122011-08-08 08:06:05 +0000[diff] [blame^]5999 &lt;clause&gt; := filter &lt;type&gt; &lt;value&gt; {, &lt;type&gt; &lt;value&gt;}*
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6000</pre>
6001
6002<h5>Overview:</h5>
6003<p>The '<tt>landingpad</tt>' instruction is used by
6004 <a href="ExceptionHandling.html#overview">LLVM's exception handling
6005 system</a> to specify that a basic block is a landing pad &mdash; one where
6006 the exception lands, and corresponds to the code found in the
6007 <i><tt>catch</tt></i> portion of a <i><tt>try/catch</tt></i> sequence. It
6008 defines values supplied by the personality function (<tt>pers_fn</tt>) upon
6009 re-entry to the function. The <tt>resultval</tt> has the
6010 type <tt>somety</tt>.</p>
6011
6012<h5>Arguments:</h5>
6013<p>This instruction takes a <tt>pers_fn</tt> value. This is the personality
6014 function associated with the unwinding mechanism. The optional
6015 <tt>cleanup</tt> flag indicates that the landing pad block is a cleanup.</p>
6016
6017<p>A <tt>clause</tt> begins with the clause type &mdash; <tt>catch</tt>
6018 or <tt>filter</tt> &mdash; and contains a list of global variables
6019 representing the "types" that may be caught or filtered respectively. The
6020 '<tt>landingpad</tt>' instruction must contain <em>at least</em>
6021 one <tt>clause</tt> or the <tt>cleanup</tt> flag.</p>
6022
6023<h5>Semantics:</h5>
6024<p>The '<tt>landingpad</tt>' instruction defines the values which are set by the
6025 personality function (<tt>pers_fn</tt>) upon re-entry to the function, and
6026 therefore the "result type" of the <tt>landingpad</tt> instruction. As with
6027 calling conventions, how the personality function results are represented in
6028 LLVM IR is target specific.</p>
6029
Bill Wendling0524b8d2011-08-03 17:17:06 +0000[diff] [blame]6030<p>The clauses are applied in order from top to bottom. If two
6031 <tt>landingpad</tt> instructions are merged together through inlining, the
Bill Wendlinga503fc02011-08-08 07:58:58 +0000[diff] [blame]6032 clauses from the calling function are appended to the list of clauses.</p>
Bill Wendling0524b8d2011-08-03 17:17:06 +0000[diff] [blame]6033
Bill Wendlingbbcb7cd2011-08-02 21:52:38 +0000[diff] [blame]6034<p>The <tt>landingpad</tt> instruction has several restrictions:</p>
6035
6036<ul>
6037 <li>A landing pad block is a basic block which is the unwind destination of an
6038 '<tt>invoke</tt>' instruction.</li>
6039 <li>A landing pad block must have a '<tt>landingpad</tt>' instruction as its
6040 first non-PHI instruction.</li>
6041 <li>There can be only one '<tt>landingpad</tt>' instruction within the landing
6042 pad block.</li>
6043 <li>A basic block that is not a landing pad block may not include a
6044 '<tt>landingpad</tt>' instruction.</li>
6045 <li>All '<tt>landingpad</tt>' instructions in a function must have the same
6046 personality function.</li>
6047</ul>
6048
6049<h5>Example:</h5>
6050<pre>
6051 ;; A landing pad which can catch an integer.
6052 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6053 catch i8** @_ZTIi
6054 ;; A landing pad that is a cleanup.
6055 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6056 cleanup
6057 ;; A landing pad which can catch an integer and can only throw a double.
6058 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6059 catch i8** @_ZTIi
6060 filter i8** @_ZTId
6061</pre>
6062
6063</div>
6064
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6065</div>
6066
6067</div>
6068
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6069<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6070<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]6071<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6072
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6073<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6074
6075<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6076 well known names and semantics and are required to follow certain
6077 restrictions. Overall, these intrinsics represent an extension mechanism for
6078 the LLVM language that does not require changing all of the transformations
6079 in LLVM when adding to the language (or the bitcode reader/writer, the
6080 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6081
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]6082<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6083 prefix is reserved in LLVM for intrinsic names; thus, function names may not
6084 begin with this prefix. Intrinsic functions must always be external
6085 functions: you cannot define the body of intrinsic functions. Intrinsic
6086 functions may only be used in call or invoke instructions: it is illegal to
6087 take the address of an intrinsic function. Additionally, because intrinsic
6088 functions are part of the LLVM language, it is required if any are added that
6089 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6090
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6091<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
6092 family of functions that perform the same operation but on different data
6093 types. Because LLVM can represent over 8 million different integer types,
6094 overloading is used commonly to allow an intrinsic function to operate on any
6095 integer type. One or more of the argument types or the result type can be
6096 overloaded to accept any integer type. Argument types may also be defined as
6097 exactly matching a previous argument's type or the result type. This allows
6098 an intrinsic function which accepts multiple arguments, but needs all of them
6099 to be of the same type, to only be overloaded with respect to a single
6100 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6101
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6102<p>Overloaded intrinsics will have the names of its overloaded argument types
6103 encoded into its function name, each preceded by a period. Only those types
6104 which are overloaded result in a name suffix. Arguments whose type is matched
6105 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6106 can take an integer of any width and returns an integer of exactly the same
6107 integer width. This leads to a family of functions such as
6108 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6109 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6110 suffix is required. Because the argument's type is matched against the return
6111 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6112
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6113<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6114 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6115
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6116<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6117<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6118 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6119</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6120
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6121<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6122
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6123<p>Variable argument support is defined in LLVM with
6124 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6125 intrinsic functions. These functions are related to the similarly named
6126 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6127
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6128<p>All of these functions operate on arguments that use a target-specific value
6129 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6130 not define what this type is, so all transformations should be prepared to
6131 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6132
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]6133<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]6134 instruction and the variable argument handling intrinsic functions are
6135 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6136
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]6137<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6138define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6139 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6140 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6141 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6142 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6143
6144 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6145 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6146
6147 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6148 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6149 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6150 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6151 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6152
6153 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6154 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]6155 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6156}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6157
6158declare void @llvm.va_start(i8*)
6159declare void @llvm.va_copy(i8*, i8*)
6160declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6161</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6162
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6163<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6164<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6165 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6166</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6167
6168
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6169<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6170
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6171<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6172<pre>
6173 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6174</pre>
6175
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6176<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6177<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6178 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]6179
6180<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6181<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]6182
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6183<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6184<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]6185 macro available in C. In a target-dependent way, it initializes
6186 the <tt>va_list</tt> element to which the argument points, so that the next
6187 call to <tt>va_arg</tt> will produce the first variable argument passed to
6188 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6189 need to know the last argument of the function as the compiler can figure
6190 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6191
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6192</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6193
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6194<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6195<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6196 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6197</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6198
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6199<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6200
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6201<h5>Syntax:</h5>
6202<pre>
6203 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6204</pre>
6205
6206<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6207<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6208 which has been initialized previously
6209 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6210 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6211
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6212<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6213<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]6214
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6215<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6216<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]6217 macro available in C. In a target-dependent way, it destroys
6218 the <tt>va_list</tt> element to which the argument points. Calls
6219 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6220 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6221 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6222
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6223</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6224
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6225<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6226<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6227 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6228</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6229
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6230<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6231
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6232<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6233<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6234 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6235</pre>
6236
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6237<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6238<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6239 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6240
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6241<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6242<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]6243 The second argument is a pointer to a <tt>va_list</tt> element to copy
6244 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6245
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6246<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6247<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]6248 macro available in C. In a target-dependent way, it copies the
6249 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6250 element. This intrinsic is necessary because
6251 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6252 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6253
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6254</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6255
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6256</div>
6257
Bill Wendling537603b2011-07-31 06:45:03 +0000[diff] [blame]6258</div>
6259
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6260<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6261<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6262 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6263</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6264
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6265<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6266
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6267<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]6268Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6269intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6270roots on the stack</a>, as well as garbage collector implementations that
6271require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6272barriers. Front-ends for type-safe garbage collected languages should generate
6273these intrinsics to make use of the LLVM garbage collectors. For more details,
6274see <a href="GarbageCollection.html">Accurate Garbage Collection with
6275LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6276
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6277<p>The garbage collection intrinsics only operate on objects in the generic
6278 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6279
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6280<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6281<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6282 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6283</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6284
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6285<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6286
6287<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6288<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6289 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6290</pre>
6291
6292<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]6293<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]6294 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6295
6296<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6297<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6298 root pointer. The second pointer (which must be either a constant or a
6299 global value address) contains the meta-data to be associated with the
6300 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6301
6302<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]6303<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]6304 location. At compile-time, the code generator generates information to allow
6305 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6306 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6307 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6308
6309</div>
6310
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6311<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6312<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6313 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6314</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6315
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6316<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6317
6318<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6319<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6320 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6321</pre>
6322
6323<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6324<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6325 locations, allowing garbage collector implementations that require read
6326 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6327
6328<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6329<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]6330 allocated from the garbage collector. The first object is a pointer to the
6331 start of the referenced object, if needed by the language runtime (otherwise
6332 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6333
6334<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6335<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6336 instruction, but may be replaced with substantially more complex code by the
6337 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6338 may only be used in a function which <a href="#gc">specifies a GC
6339 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6340
6341</div>
6342
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6343<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6344<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6345 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6346</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6347
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6348<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6349
6350<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6351<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6352 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6353</pre>
6354
6355<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6356<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6357 locations, allowing garbage collector implementations that require write
6358 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6359
6360<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6361<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]6362 object to store it to, and the third is the address of the field of Obj to
6363 store to. If the runtime does not require a pointer to the object, Obj may
6364 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6365
6366<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6367<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6368 instruction, but may be replaced with substantially more complex code by the
6369 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6370 may only be used in a function which <a href="#gc">specifies a GC
6371 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6372
6373</div>
6374
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6375</div>
6376
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6377<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6378<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6379 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6380</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6381
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6382<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6383
6384<p>These intrinsics are provided by LLVM to expose special features that may
6385 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6386
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6387<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6388<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6389 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6390</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6391
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6392<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6393
6394<h5>Syntax:</h5>
6395<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6396 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6397</pre>
6398
6399<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6400<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6401 target-specific value indicating the return address of the current function
6402 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6403
6404<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6405<p>The argument to this intrinsic indicates which function to return the address
6406 for. Zero indicates the calling function, one indicates its caller, etc.
6407 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6408
6409<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6410<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6411 indicating the return address of the specified call frame, or zero if it
6412 cannot be identified. The value returned by this intrinsic is likely to be
6413 incorrect or 0 for arguments other than zero, so it should only be used for
6414 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6415
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6416<p>Note that calling this intrinsic does not prevent function inlining or other
6417 aggressive transformations, so the value returned may not be that of the
6418 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6419
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6420</div>
6421
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6422<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6423<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6424 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6425</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6426
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6427<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6428
6429<h5>Syntax:</h5>
6430<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6431 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6432</pre>
6433
6434<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6435<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6436 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6437
6438<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6439<p>The argument to this intrinsic indicates which function to return the frame
6440 pointer for. Zero indicates the calling function, one indicates its caller,
6441 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6442
6443<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6444<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6445 indicating the frame address of the specified call frame, or zero if it
6446 cannot be identified. The value returned by this intrinsic is likely to be
6447 incorrect or 0 for arguments other than zero, so it should only be used for
6448 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6449
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6450<p>Note that calling this intrinsic does not prevent function inlining or other
6451 aggressive transformations, so the value returned may not be that of the
6452 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6453
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6454</div>
6455
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6456<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6457<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6458 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6459</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6460
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6461<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6462
6463<h5>Syntax:</h5>
6464<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6465 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6466</pre>
6467
6468<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6469<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6470 of the function stack, for use
6471 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6472 useful for implementing language features like scoped automatic variable
6473 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6474
6475<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6476<p>This intrinsic returns a opaque pointer value that can be passed
6477 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6478 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6479 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6480 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6481 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6482 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6483
6484</div>
6485
6486<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6487<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6488 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6489</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6490
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6491<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6492
6493<h5>Syntax:</h5>
6494<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6495 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6496</pre>
6497
6498<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6499<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6500 the function stack to the state it was in when the
6501 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6502 executed. This is useful for implementing language features like scoped
6503 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6504
6505<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6506<p>See the description
6507 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6508
6509</div>
6510
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6511<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6512<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6513 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6514</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6515
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6516<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6517
6518<h5>Syntax:</h5>
6519<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6520 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]6521</pre>
6522
6523<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6524<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6525 insert a prefetch instruction if supported; otherwise, it is a noop.
6526 Prefetches have no effect on the behavior of the program but can change its
6527 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6528
6529<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6530<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6531 specifier determining if the fetch should be for a read (0) or write (1),
6532 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6533 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6534 specifies whether the prefetch is performed on the data (1) or instruction (0)
6535 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6536 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6537
6538<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6539<p>This intrinsic does not modify the behavior of the program. In particular,
6540 prefetches cannot trap and do not produce a value. On targets that support
6541 this intrinsic, the prefetch can provide hints to the processor cache for
6542 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6543
6544</div>
6545
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6546<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6547<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6548 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6549</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6550
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6551<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6552
6553<h5>Syntax:</h5>
6554<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6555 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6556</pre>
6557
6558<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6559<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6560 Counter (PC) in a region of code to simulators and other tools. The method
6561 is target specific, but it is expected that the marker will use exported
6562 symbols to transmit the PC of the marker. The marker makes no guarantees
6563 that it will remain with any specific instruction after optimizations. It is
6564 possible that the presence of a marker will inhibit optimizations. The
6565 intended use is to be inserted after optimizations to allow correlations of
6566 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6567
6568<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6569<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6570
6571<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6572<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6573 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6574
6575</div>
6576
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6577<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6578<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6579 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6580</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6581
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6582<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6583
6584<h5>Syntax:</h5>
6585<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6586 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6587</pre>
6588
6589<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6590<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6591 counter register (or similar low latency, high accuracy clocks) on those
6592 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6593 should map to RPCC. As the backing counters overflow quickly (on the order
6594 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6595
6596<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6597<p>When directly supported, reading the cycle counter should not modify any
6598 memory. Implementations are allowed to either return a application specific
6599 value or a system wide value. On backends without support, this is lowered
6600 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6601
6602</div>
6603
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6604</div>
6605
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6606<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6607<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6608 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6609</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6610
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6611<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6612
6613<p>LLVM provides intrinsics for a few important standard C library functions.
6614 These intrinsics allow source-language front-ends to pass information about
6615 the alignment of the pointer arguments to the code generator, providing
6616 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6617
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6618<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6619<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6620 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6621</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6622
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6623<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6624
6625<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6626<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]6627 integer bit width and for different address spaces. Not all targets support
6628 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6629
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6630<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6631 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]6632 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6633 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]6634 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6635</pre>
6636
6637<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6638<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6639 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6640
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6641<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6642 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6643 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6644
6645<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6646
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6647<p>The first argument is a pointer to the destination, the second is a pointer
6648 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6649 number of bytes to copy, the fourth argument is the alignment of the
6650 source and destination locations, and the fifth is a boolean indicating a
6651 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6652
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6653<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]6654 then the caller guarantees that both the source and destination pointers are
6655 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6656
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6657<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6658 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6659 The detailed access behavior is not very cleanly specified and it is unwise
6660 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6661
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6662<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6663
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6664<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6665 source location to the destination location, which are not allowed to
6666 overlap. It copies "len" bytes of memory over. If the argument is known to
6667 be aligned to some boundary, this can be specified as the fourth argument,
6668 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6669
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6670</div>
6671
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6672<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6673<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6674 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6675</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6676
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6677<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6678
6679<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6680<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]6681 width and for different address space. Not all targets support all bit
6682 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6683
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6684<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6685 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]6686 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6687 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]6688 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6689</pre>
6690
6691<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6692<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6693 source location to the destination location. It is similar to the
6694 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6695 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6696
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6697<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6698 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6699 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6700
6701<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6702
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6703<p>The first argument is a pointer to the destination, the second is a pointer
6704 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6705 number of bytes to copy, the fourth argument is the alignment of the
6706 source and destination locations, and the fifth is a boolean indicating a
6707 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6708
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6709<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]6710 then the caller guarantees that the source and destination pointers are
6711 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6712
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6713<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6714 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6715 The detailed access behavior is not very cleanly specified and it is unwise
6716 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6717
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6718<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6719
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6720<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6721 source location to the destination location, which may overlap. It copies
6722 "len" bytes of memory over. If the argument is known to be aligned to some
6723 boundary, this can be specified as the fourth argument, otherwise it should
6724 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6725
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6726</div>
6727
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6728<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6729<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6730 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6731</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6732
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6733<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6734
6735<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6736<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]6737 width and for different address spaces. However, not all targets support all
6738 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6739
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6740<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6741 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6742 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6743 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6744 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6745</pre>
6746
6747<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6748<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6749 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6750
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6751<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6752 intrinsic does not return a value and takes extra alignment/volatile
6753 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6754
6755<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6756<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]6757 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6758 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6759 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6760
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6761<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]6762 then the caller guarantees that the destination pointer is aligned to that
6763 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6764
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6765<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6766 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6767 The detailed access behavior is not very cleanly specified and it is unwise
6768 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6769
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6770<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6771<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6772 at the destination location. If the argument is known to be aligned to some
6773 boundary, this can be specified as the fourth argument, otherwise it should
6774 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6775
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6776</div>
6777
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6778<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6779<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6780 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6781</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6782
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6783<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6784
6785<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6786<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6787 floating point or vector of floating point type. Not all targets support all
6788 types however.</p>
6789
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6790<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6791 declare float @llvm.sqrt.f32(float %Val)
6792 declare double @llvm.sqrt.f64(double %Val)
6793 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6794 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6795 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6796</pre>
6797
6798<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6799<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6800 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6801 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6802 behavior for negative numbers other than -0.0 (which allows for better
6803 optimization, because there is no need to worry about errno being
6804 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]6805
6806<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6807<p>The argument and return value are floating point numbers of the same
6808 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6809
6810<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6811<p>This function returns the sqrt of the specified operand if it is a
6812 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6813
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6814</div>
6815
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6816<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6817<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6818 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6819</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6820
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6821<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6822
6823<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6824<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6825 floating point or vector of floating point type. Not all targets support all
6826 types however.</p>
6827
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6828<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6829 declare float @llvm.powi.f32(float %Val, i32 %power)
6830 declare double @llvm.powi.f64(double %Val, i32 %power)
6831 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6832 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6833 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6834</pre>
6835
6836<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6837<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6838 specified (positive or negative) power. The order of evaluation of
6839 multiplications is not defined. When a vector of floating point type is
6840 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6841
6842<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6843<p>The second argument is an integer power, and the first is a value to raise to
6844 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6845
6846<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6847<p>This function returns the first value raised to the second power with an
6848 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6849
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6850</div>
6851
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6852<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6853<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6854 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6855</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6856
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6857<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6858
6859<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6860<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6861 floating point or vector of floating point type. Not all targets support all
6862 types however.</p>
6863
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6864<pre>
6865 declare float @llvm.sin.f32(float %Val)
6866 declare double @llvm.sin.f64(double %Val)
6867 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6868 declare fp128 @llvm.sin.f128(fp128 %Val)
6869 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6870</pre>
6871
6872<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6873<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6874
6875<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6876<p>The argument and return value are floating point numbers of the same
6877 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6878
6879<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6880<p>This function returns the sine of the specified operand, returning the same
6881 values as the libm <tt>sin</tt> functions would, and handles error conditions
6882 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6883
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6884</div>
6885
6886<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6887<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6888 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6889</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6890
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6891<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6892
6893<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6894<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6895 floating point or vector of floating point type. Not all targets support all
6896 types however.</p>
6897
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6898<pre>
6899 declare float @llvm.cos.f32(float %Val)
6900 declare double @llvm.cos.f64(double %Val)
6901 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6902 declare fp128 @llvm.cos.f128(fp128 %Val)
6903 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6904</pre>
6905
6906<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6907<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6908
6909<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6910<p>The argument and return value are floating point numbers of the same
6911 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6912
6913<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6914<p>This function returns the cosine of the specified operand, returning the same
6915 values as the libm <tt>cos</tt> functions would, and handles error conditions
6916 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6917
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6918</div>
6919
6920<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6921<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6922 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6923</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6924
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6925<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6926
6927<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6928<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6929 floating point or vector of floating point type. Not all targets support all
6930 types however.</p>
6931
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6932<pre>
6933 declare float @llvm.pow.f32(float %Val, float %Power)
6934 declare double @llvm.pow.f64(double %Val, double %Power)
6935 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6936 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6937 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6938</pre>
6939
6940<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6941<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6942 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6943
6944<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6945<p>The second argument is a floating point power, and the first is a value to
6946 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6947
6948<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6949<p>This function returns the first value raised to the second power, returning
6950 the same values as the libm <tt>pow</tt> functions would, and handles error
6951 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6952
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6953</div>
6954
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6955</div>
6956
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6957<!-- _______________________________________________________________________ -->
6958<h4>
6959 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6960</h4>
6961
6962<div>
6963
6964<h5>Syntax:</h5>
6965<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6966 floating point or vector of floating point type. Not all targets support all
6967 types however.</p>
6968
6969<pre>
6970 declare float @llvm.exp.f32(float %Val)
6971 declare double @llvm.exp.f64(double %Val)
6972 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6973 declare fp128 @llvm.exp.f128(fp128 %Val)
6974 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6975</pre>
6976
6977<h5>Overview:</h5>
6978<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6979
6980<h5>Arguments:</h5>
6981<p>The argument and return value are floating point numbers of the same
6982 type.</p>
6983
6984<h5>Semantics:</h5>
6985<p>This function returns the same values as the libm <tt>exp</tt> functions
6986 would, and handles error conditions in the same way.</p>
6987
6988</div>
6989
6990<!-- _______________________________________________________________________ -->
6991<h4>
6992 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6993</h4>
6994
6995<div>
6996
6997<h5>Syntax:</h5>
6998<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6999 floating point or vector of floating point type. Not all targets support all
7000 types however.</p>
7001
7002<pre>
7003 declare float @llvm.log.f32(float %Val)
7004 declare double @llvm.log.f64(double %Val)
7005 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
7006 declare fp128 @llvm.log.f128(fp128 %Val)
7007 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
7008</pre>
7009
7010<h5>Overview:</h5>
7011<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
7012
7013<h5>Arguments:</h5>
7014<p>The argument and return value are floating point numbers of the same
7015 type.</p>
7016
7017<h5>Semantics:</h5>
7018<p>This function returns the same values as the libm <tt>log</tt> functions
7019 would, and handles error conditions in the same way.</p>
7020
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]7021<h4>
7022 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
7023</h4>
7024
7025<div>
7026
7027<h5>Syntax:</h5>
7028<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
7029 floating point or vector of floating point type. Not all targets support all
7030 types however.</p>
7031
7032<pre>
7033 declare float @llvm.fma.f32(float %a, float %b, float %c)
7034 declare double @llvm.fma.f64(double %a, double %b, double %c)
7035 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
7036 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
7037 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
7038</pre>
7039
7040<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]7041<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]7042 operation.</p>
7043
7044<h5>Arguments:</h5>
7045<p>The argument and return value are floating point numbers of the same
7046 type.</p>
7047
7048<h5>Semantics:</h5>
7049<p>This function returns the same values as the libm <tt>fma</tt> functions
7050 would.</p>
7051
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]7052</div>
7053
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7054<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7055<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7056 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7057</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7058
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7059<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7060
7061<p>LLVM provides intrinsics for a few important bit manipulation operations.
7062 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7063
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7064<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7065<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]7066 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7067</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7068
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7069<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7070
7071<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]7072<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7073 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
7074
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7075<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7076 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
7077 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
7078 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7079</pre>
7080
7081<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7082<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
7083 values with an even number of bytes (positive multiple of 16 bits). These
7084 are useful for performing operations on data that is not in the target's
7085 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7086
7087<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7088<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
7089 and low byte of the input i16 swapped. Similarly,
7090 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
7091 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
7092 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
7093 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
7094 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
7095 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7096
7097</div>
7098
7099<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7100<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]7101 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7102</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7103
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7104<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7105
7106<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]7107<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]7108 width, or on any vector with integer elements. Not all targets support all
7109 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7110
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7111<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7112 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7113 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7114 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7115 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7116 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7117 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]7118</pre>
7119
7120<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7121<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7122 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7123
7124<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7125<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]7126 integer type, or a vector with integer elements.
7127 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7128
7129<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7130<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7131 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7132
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7133</div>
7134
7135<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7136<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7137 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7138</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7139
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7140<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7141
7142<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7143<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]7144 integer bit width, or any vector whose elements are integers. Not all
7145 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7146
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7147<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7148 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7149 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7150 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7151 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7152 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7153 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]7154</pre>
7155
7156<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7157<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7158 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7159
7160<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7161<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]7162 integer type, or any vector type with integer element type.
7163 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7164
7165<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7166<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7167 zeros in a variable, or within each element of the vector if the operation
7168 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]7169 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7170
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7171</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]7172
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7173<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7174<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7175 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7176</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7177
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7178<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7179
7180<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7181<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]7182 integer bit width, or any vector of integer elements. Not all targets
7183 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7184
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7185<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7186 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7187 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7188 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7189 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7190 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7191 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]7192</pre>
7193
7194<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7195<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7196 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7197
7198<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7199<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]7200 integer type, or a vectory with integer element type.. The return type
7201 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7202
7203<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7204<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7205 zeros in a variable, or within each element of a vector.
7206 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7207 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7208
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7209</div>
7210
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7211</div>
7212
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7213<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7214<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7215 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7216</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7217
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7218<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7219
7220<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7221
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7222<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7223<h4>
7224 <a name="int_sadd_overflow">
7225 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7226 </a>
7227</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7228
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7229<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7230
7231<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7232<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]7233 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7234
7235<pre>
7236 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7237 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7238 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7239</pre>
7240
7241<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7242<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7243 a signed addition of the two arguments, and indicate whether an overflow
7244 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7245
7246<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7247<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]7248 be of integer types of any bit width, but they must have the same bit
7249 width. The second element of the result structure must be of
7250 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7251 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7252
7253<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7254<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7255 a signed addition of the two variables. They return a structure &mdash; the
7256 first element of which is the signed summation, and the second element of
7257 which is a bit specifying if the signed summation resulted in an
7258 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7259
7260<h5>Examples:</h5>
7261<pre>
7262 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7263 %sum = extractvalue {i32, i1} %res, 0
7264 %obit = extractvalue {i32, i1} %res, 1
7265 br i1 %obit, label %overflow, label %normal
7266</pre>
7267
7268</div>
7269
7270<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7271<h4>
7272 <a name="int_uadd_overflow">
7273 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7274 </a>
7275</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7276
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7277<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7278
7279<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7280<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]7281 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7282
7283<pre>
7284 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7285 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7286 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7287</pre>
7288
7289<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7290<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7291 an unsigned addition of the two arguments, and indicate whether a carry
7292 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7293
7294<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7295<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]7296 be of integer types of any bit width, but they must have the same bit
7297 width. The second element of the result structure must be of
7298 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7299 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7300
7301<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7302<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7303 an unsigned addition of the two arguments. They return a structure &mdash;
7304 the first element of which is the sum, and the second element of which is a
7305 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7306
7307<h5>Examples:</h5>
7308<pre>
7309 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7310 %sum = extractvalue {i32, i1} %res, 0
7311 %obit = extractvalue {i32, i1} %res, 1
7312 br i1 %obit, label %carry, label %normal
7313</pre>
7314
7315</div>
7316
7317<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7318<h4>
7319 <a name="int_ssub_overflow">
7320 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7321 </a>
7322</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7323
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7324<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7325
7326<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7327<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]7328 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7329
7330<pre>
7331 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7332 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7333 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7334</pre>
7335
7336<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7337<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7338 a signed subtraction of the two arguments, and indicate whether an overflow
7339 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7340
7341<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7342<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]7343 be of integer types of any bit width, but they must have the same bit
7344 width. The second element of the result structure must be of
7345 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7346 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7347
7348<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7349<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7350 a signed subtraction of the two arguments. They return a structure &mdash;
7351 the first element of which is the subtraction, and the second element of
7352 which is a bit specifying if the signed subtraction resulted in an
7353 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7354
7355<h5>Examples:</h5>
7356<pre>
7357 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7358 %sum = extractvalue {i32, i1} %res, 0
7359 %obit = extractvalue {i32, i1} %res, 1
7360 br i1 %obit, label %overflow, label %normal
7361</pre>
7362
7363</div>
7364
7365<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7366<h4>
7367 <a name="int_usub_overflow">
7368 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7369 </a>
7370</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7371
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7372<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7373
7374<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7375<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]7376 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7377
7378<pre>
7379 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7380 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7381 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7382</pre>
7383
7384<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7385<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7386 an unsigned subtraction of the two arguments, and indicate whether an
7387 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7388
7389<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7390<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]7391 be of integer types of any bit width, but they must have the same bit
7392 width. The second element of the result structure must be of
7393 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7394 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7395
7396<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7397<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7398 an unsigned subtraction of the two arguments. They return a structure &mdash;
7399 the first element of which is the subtraction, and the second element of
7400 which is a bit specifying if the unsigned subtraction resulted in an
7401 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7402
7403<h5>Examples:</h5>
7404<pre>
7405 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7406 %sum = extractvalue {i32, i1} %res, 0
7407 %obit = extractvalue {i32, i1} %res, 1
7408 br i1 %obit, label %overflow, label %normal
7409</pre>
7410
7411</div>
7412
7413<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7414<h4>
7415 <a name="int_smul_overflow">
7416 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7417 </a>
7418</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7419
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7420<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7421
7422<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7423<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]7424 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7425
7426<pre>
7427 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7428 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7429 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7430</pre>
7431
7432<h5>Overview:</h5>
7433
7434<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7435 a signed multiplication of the two arguments, and indicate whether an
7436 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7437
7438<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7439<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]7440 be of integer types of any bit width, but they must have the same bit
7441 width. The second element of the result structure must be of
7442 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7443 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7444
7445<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7446<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7447 a signed multiplication of the two arguments. They return a structure &mdash;
7448 the first element of which is the multiplication, and the second element of
7449 which is a bit specifying if the signed multiplication resulted in an
7450 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7451
7452<h5>Examples:</h5>
7453<pre>
7454 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7455 %sum = extractvalue {i32, i1} %res, 0
7456 %obit = extractvalue {i32, i1} %res, 1
7457 br i1 %obit, label %overflow, label %normal
7458</pre>
7459
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7460</div>
7461
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7462<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7463<h4>
7464 <a name="int_umul_overflow">
7465 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7466 </a>
7467</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7468
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7469<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7470
7471<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7472<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]7473 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7474
7475<pre>
7476 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7477 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7478 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7479</pre>
7480
7481<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7482<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7483 a unsigned multiplication of the two arguments, and indicate whether an
7484 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7485
7486<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7487<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]7488 be of integer types of any bit width, but they must have the same bit
7489 width. The second element of the result structure must be of
7490 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7491 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7492
7493<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7494<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7495 an unsigned multiplication of the two arguments. They return a structure
7496 &mdash; the first element of which is the multiplication, and the second
7497 element of which is a bit specifying if the unsigned multiplication resulted
7498 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7499
7500<h5>Examples:</h5>
7501<pre>
7502 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7503 %sum = extractvalue {i32, i1} %res, 0
7504 %obit = extractvalue {i32, i1} %res, 1
7505 br i1 %obit, label %overflow, label %normal
7506</pre>
7507
7508</div>
7509
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7510</div>
7511
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7512<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7513<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7514 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7515</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7516
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7517<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7518
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7519<p>Half precision floating point is a storage-only format. This means that it is
7520 a dense encoding (in memory) but does not support computation in the
7521 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7522
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7523<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7524 value as an i16, then convert it to float with <a
7525 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7526 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7527 double etc). To store the value back to memory, it is first converted to
7528 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7529 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7530 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7531
7532<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7533<h4>
7534 <a name="int_convert_to_fp16">
7535 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7536 </a>
7537</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7538
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7539<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7540
7541<h5>Syntax:</h5>
7542<pre>
7543 declare i16 @llvm.convert.to.fp16(f32 %a)
7544</pre>
7545
7546<h5>Overview:</h5>
7547<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7548 a conversion from single precision floating point format to half precision
7549 floating point format.</p>
7550
7551<h5>Arguments:</h5>
7552<p>The intrinsic function contains single argument - the value to be
7553 converted.</p>
7554
7555<h5>Semantics:</h5>
7556<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7557 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7558 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7559 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7560
7561<h5>Examples:</h5>
7562<pre>
7563 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7564 store i16 %res, i16* @x, align 2
7565</pre>
7566
7567</div>
7568
7569<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7570<h4>
7571 <a name="int_convert_from_fp16">
7572 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7573 </a>
7574</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7575
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7576<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7577
7578<h5>Syntax:</h5>
7579<pre>
7580 declare f32 @llvm.convert.from.fp16(i16 %a)
7581</pre>
7582
7583<h5>Overview:</h5>
7584<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7585 a conversion from half precision floating point format to single precision
7586 floating point format.</p>
7587
7588<h5>Arguments:</h5>
7589<p>The intrinsic function contains single argument - the value to be
7590 converted.</p>
7591
7592<h5>Semantics:</h5>
7593<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7594 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7595 precision floating point format. The input half-float value is represented by
7596 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7597
7598<h5>Examples:</h5>
7599<pre>
7600 %a = load i16* @x, align 2
7601 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7602</pre>
7603
7604</div>
7605
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7606</div>
7607
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7608<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7609<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7610 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7611</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7612
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7613<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7614
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7615<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7616 prefix), are described in
7617 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7618 Level Debugging</a> document.</p>
7619
7620</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7621
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7622<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7623<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7624 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7625</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7626
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7627<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7628
7629<p>The LLVM exception handling intrinsics (which all start with
7630 <tt>llvm.eh.</tt> prefix), are described in
7631 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7632 Handling</a> document.</p>
7633
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7634</div>
7635
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7636<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7637<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7638 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7639</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7640
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7641<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7642
7643<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7644 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7645 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7646 function pointer lacking the nest parameter - the caller does not need to
7647 provide a value for it. Instead, the value to use is stored in advance in a
7648 "trampoline", a block of memory usually allocated on the stack, which also
7649 contains code to splice the nest value into the argument list. This is used
7650 to implement the GCC nested function address extension.</p>
7651
7652<p>For example, if the function is
7653 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7654 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7655 follows:</p>
7656
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7657<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7658 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7659 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7660 %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]7661 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7662</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7663
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7664<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7665 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7666
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7667<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7668<h4>
7669 <a name="int_it">
7670 '<tt>llvm.init.trampoline</tt>' Intrinsic
7671 </a>
7672</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7673
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7674<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7675
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7676<h5>Syntax:</h5>
7677<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7678 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]7679</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7680
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7681<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7682<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7683 function pointer suitable for executing it.</p>
7684
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7685<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7686<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7687 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7688 sufficiently aligned block of memory; this memory is written to by the
7689 intrinsic. Note that the size and the alignment are target-specific - LLVM
7690 currently provides no portable way of determining them, so a front-end that
7691 generates this intrinsic needs to have some target-specific knowledge.
7692 The <tt>func</tt> argument must hold a function bitcast to
7693 an <tt>i8*</tt>.</p>
7694
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7695<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7696<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7697 dependent code, turning it into a function. A pointer to this function is
7698 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7699 function pointer type</a> before being called. The new function's signature
7700 is the same as that of <tt>func</tt> with any arguments marked with
7701 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7702 is allowed, and it must be of pointer type. Calling the new function is
7703 equivalent to calling <tt>func</tt> with the same argument list, but
7704 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7705 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7706 by <tt>tramp</tt> is modified, then the effect of any later call to the
7707 returned function pointer is undefined.</p>
7708
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7709</div>
7710
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7711</div>
7712
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7713<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7714<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7715 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7716</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7717
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7718<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7719
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7720<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7721 hardware constructs for atomic operations and memory synchronization. This
7722 provides an interface to the hardware, not an interface to the programmer. It
7723 is aimed at a low enough level to allow any programming models or APIs
7724 (Application Programming Interfaces) which need atomic behaviors to map
7725 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7726 hardware provides a "universal IR" for source languages, it also provides a
7727 starting point for developing a "universal" atomic operation and
7728 synchronization IR.</p>
7729
7730<p>These do <em>not</em> form an API such as high-level threading libraries,
7731 software transaction memory systems, atomic primitives, and intrinsic
7732 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7733 application libraries. The hardware interface provided by LLVM should allow
7734 a clean implementation of all of these APIs and parallel programming models.
7735 No one model or paradigm should be selected above others unless the hardware
7736 itself ubiquitously does so.</p>
7737
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7738<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7739<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7740 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7741</h4>
7742
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7743<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7744<h5>Syntax:</h5>
7745<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7746 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]7747</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7748
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7749<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7750<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7751 specific pairs of memory access types.</p>
7752
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7753<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7754<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7755 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7756 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7757 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7758
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7759<ul>
7760 <li><tt>ll</tt>: load-load barrier</li>
7761 <li><tt>ls</tt>: load-store barrier</li>
7762 <li><tt>sl</tt>: store-load barrier</li>
7763 <li><tt>ss</tt>: store-store barrier</li>
7764 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7765</ul>
7766
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7767<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7768<p>This intrinsic causes the system to enforce some ordering constraints upon
7769 the loads and stores of the program. This barrier does not
7770 indicate <em>when</em> any events will occur, it only enforces
7771 an <em>order</em> in which they occur. For any of the specified pairs of load
7772 and store operations (f.ex. load-load, or store-load), all of the first
7773 operations preceding the barrier will complete before any of the second
7774 operations succeeding the barrier begin. Specifically the semantics for each
7775 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7776
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7777<ul>
7778 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7779 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7780 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7781 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7782 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7783 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7784 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7785 load after the barrier begins.</li>
7786</ul>
7787
7788<p>These semantics are applied with a logical "and" behavior when more than one
7789 is enabled in a single memory barrier intrinsic.</p>
7790
7791<p>Backends may implement stronger barriers than those requested when they do
7792 not support as fine grained a barrier as requested. Some architectures do
7793 not need all types of barriers and on such architectures, these become
7794 noops.</p>
7795
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7796<h5>Example:</h5>
7797<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7798%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7799%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7800 store i32 4, %ptr
7801
7802%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7803 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]7804 <i>; guarantee the above finishes</i>
7805 store i32 8, %ptr <i>; before this begins</i>
7806</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7807
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7808</div>
7809
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7810<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7811<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7812 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7813</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7814
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7815<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7816
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7817<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7818<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7819 any integer bit width and for different address spaces. Not all targets
7820 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7821
7822<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7823 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7824 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7825 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7826 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]7827</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7828
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7829<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7830<p>This loads a value in memory and compares it to a given value. If they are
7831 equal, it stores a new value into the memory.</p>
7832
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7833<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7834<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7835 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7836 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7837 this integer type. While any bit width integer may be used, targets may only
7838 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7839
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7840<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7841<p>This entire intrinsic must be executed atomically. It first loads the value
7842 in memory pointed to by <tt>ptr</tt> and compares it with the
7843 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7844 memory. The loaded value is yielded in all cases. This provides the
7845 equivalent of an atomic compare-and-swap operation within the SSA
7846 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7847
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7848<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7849<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7850%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7851%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7852 store i32 4, %ptr
7853
7854%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7855%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7856 <i>; yields {i32}:result1 = 4</i>
7857%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7858%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7859
7860%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7861%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7862 <i>; yields {i32}:result2 = 8</i>
7863%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7864
7865%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7866</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7867
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7868</div>
7869
7870<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7871<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7872 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7873</h4>
7874
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7875<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7876<h5>Syntax:</h5>
7877
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7878<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7879 integer bit width. Not all targets support all bit widths however.</p>
7880
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7881<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7882 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7883 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7884 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7885 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]7886</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7887
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7888<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7889<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7890 the value from memory. It then stores the value in <tt>val</tt> in the memory
7891 at <tt>ptr</tt>.</p>
7892
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7893<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7894<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7895 the <tt>val</tt> argument and the result must be integers of the same bit
7896 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7897 integer type. The targets may only lower integer representations they
7898 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7899
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7900<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7901<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7902 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7903 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7904
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7905<h5>Examples:</h5>
7906<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7907%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7908%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7909 store i32 4, %ptr
7910
7911%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7912%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7913 <i>; yields {i32}:result1 = 4</i>
7914%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7915%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7916
7917%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7918%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7919 <i>; yields {i32}:result2 = 8</i>
7920
7921%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7922%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7923</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7924
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7925</div>
7926
7927<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7928<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7929 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7930</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7931
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7932<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7933
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7934<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7935<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7936 any integer bit width. Not all targets support all bit widths however.</p>
7937
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7938<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7939 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7940 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7941 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7942 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]7943</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7944
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7945<h5>Overview:</h5>
7946<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7947 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7948
7949<h5>Arguments:</h5>
7950<p>The intrinsic takes two arguments, the first a pointer to an integer value
7951 and the second an integer value. The result is also an integer value. These
7952 integer types can have any bit width, but they must all have the same bit
7953 width. The targets may only lower integer representations they support.</p>
7954
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7955<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7956<p>This intrinsic does a series of operations atomically. It first loads the
7957 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7958 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]7959
7960<h5>Examples:</h5>
7961<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7962%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7963%ptr = bitcast i8* %mallocP to i32*
7964 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7965%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7966 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7967%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7968 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7969%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7970 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7971%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7972</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7973
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7974</div>
7975
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7976<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7977<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7978 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7979</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7980
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7981<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7982
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7983<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7984<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7985 any integer bit width and for different address spaces. Not all targets
7986 support all bit widths however.</p>
7987
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7988<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7989 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7990 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7991 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7992 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]7993</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7994
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7995<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7996<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7997 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7998
7999<h5>Arguments:</h5>
8000<p>The intrinsic takes two arguments, the first a pointer to an integer value
8001 and the second an integer value. The result is also an integer value. These
8002 integer types can have any bit width, but they must all have the same bit
8003 width. The targets may only lower integer representations they support.</p>
8004
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8005<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8006<p>This intrinsic does a series of operations atomically. It first loads the
8007 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
8008 result to <tt>ptr</tt>. It yields the original value stored
8009 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8010
8011<h5>Examples:</h5>
8012<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]8013%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8014%ptr = bitcast i8* %mallocP to i32*
8015 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8016%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8017 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8018%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8019 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8020%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8021 <i>; yields {i32}:result3 = 2</i>
8022%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
8023</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8024
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8025</div>
8026
8027<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8028<h4>
8029 <a name="int_atomic_load_and">
8030 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
8031 </a>
8032 <br>
8033 <a name="int_atomic_load_nand">
8034 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
8035 </a>
8036 <br>
8037 <a name="int_atomic_load_or">
8038 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
8039 </a>
8040 <br>
8041 <a name="int_atomic_load_xor">
8042 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
8043 </a>
8044</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8045
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8046<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8047
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8048<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8049<p>These are overloaded intrinsics. You can
8050 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
8051 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
8052 bit width and for different address spaces. Not all targets support all bit
8053 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8054
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8055<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8056 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8057 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8058 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8059 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]8060</pre>
8061
8062<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8063 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8064 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8065 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8066 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]8067</pre>
8068
8069<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8070 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8071 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8072 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8073 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]8074</pre>
8075
8076<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8077 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8078 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8079 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8080 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]8081</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8082
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8083<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8084<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
8085 the value stored in memory at <tt>ptr</tt>. It yields the original value
8086 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8087
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8088<h5>Arguments:</h5>
8089<p>These intrinsics take two arguments, the first a pointer to an integer value
8090 and the second an integer value. The result is also an integer value. These
8091 integer types can have any bit width, but they must all have the same bit
8092 width. The targets may only lower integer representations they support.</p>
8093
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8094<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8095<p>These intrinsics does a series of operations atomically. They first load the
8096 value stored at <tt>ptr</tt>. They then do the bitwise
8097 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
8098 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8099
8100<h5>Examples:</h5>
8101<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]8102%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8103%ptr = bitcast i8* %mallocP to i32*
8104 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8105%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8106 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8107%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8108 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8109%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8110 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8111%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8112 <i>; yields {i32}:result3 = FF</i>
8113%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
8114</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8115
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8116</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8117
8118<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8119<h4>
8120 <a name="int_atomic_load_max">
8121 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
8122 </a>
8123 <br>
8124 <a name="int_atomic_load_min">
8125 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
8126 </a>
8127 <br>
8128 <a name="int_atomic_load_umax">
8129 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
8130 </a>
8131 <br>
8132 <a name="int_atomic_load_umin">
8133 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8134 </a>
8135</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8136
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8137<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8138
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8139<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8140<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8141 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8142 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8143 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8144
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8145<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8146 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8147 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8148 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8149 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]8150</pre>
8151
8152<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8153 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8154 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8155 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8156 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]8157</pre>
8158
8159<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8160 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8161 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8162 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8163 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]8164</pre>
8165
8166<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8167 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8168 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8169 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8170 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]8171</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8172
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8173<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8174<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8175 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8176 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8177
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8178<h5>Arguments:</h5>
8179<p>These intrinsics take two arguments, the first a pointer to an integer value
8180 and the second an integer value. The result is also an integer value. These
8181 integer types can have any bit width, but they must all have the same bit
8182 width. The targets may only lower integer representations they support.</p>
8183
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8184<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8185<p>These intrinsics does a series of operations atomically. They first load the
8186 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8187 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8188 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8189
8190<h5>Examples:</h5>
8191<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]8192%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8193%ptr = bitcast i8* %mallocP to i32*
8194 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8195%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8196 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8197%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8198 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8199%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8200 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8201%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8202 <i>; yields {i32}:result3 = 8</i>
8203%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8204</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8205
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8206</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8207
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8208</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8209
8210<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8211<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8212 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8213</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8214
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8215<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8216
8217<p>This class of intrinsics exists to information about the lifetime of memory
8218 objects and ranges where variables are immutable.</p>
8219
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8220<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8221<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8222 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8223</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8224
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8225<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8226
8227<h5>Syntax:</h5>
8228<pre>
8229 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8230</pre>
8231
8232<h5>Overview:</h5>
8233<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8234 object's lifetime.</p>
8235
8236<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8237<p>The first argument is a constant integer representing the size of the
8238 object, or -1 if it is variable sized. The second argument is a pointer to
8239 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8240
8241<h5>Semantics:</h5>
8242<p>This intrinsic indicates that before this point in the code, the value of the
8243 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]8244 never be used and has an undefined value. A load from the pointer that
8245 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8246 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8247
8248</div>
8249
8250<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8251<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8252 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8253</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8254
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8255<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8256
8257<h5>Syntax:</h5>
8258<pre>
8259 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8260</pre>
8261
8262<h5>Overview:</h5>
8263<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8264 object's lifetime.</p>
8265
8266<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8267<p>The first argument is a constant integer representing the size of the
8268 object, or -1 if it is variable sized. The second argument is a pointer to
8269 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8270
8271<h5>Semantics:</h5>
8272<p>This intrinsic indicates that after this point in the code, the value of the
8273 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8274 never be used and has an undefined value. Any stores into the memory object
8275 following this intrinsic may be removed as dead.
8276
8277</div>
8278
8279<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8280<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8281 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8282</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8283
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8284<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8285
8286<h5>Syntax:</h5>
8287<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]8288 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8289</pre>
8290
8291<h5>Overview:</h5>
8292<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8293 a memory object will not change.</p>
8294
8295<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8296<p>The first argument is a constant integer representing the size of the
8297 object, or -1 if it is variable sized. The second argument is a pointer to
8298 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8299
8300<h5>Semantics:</h5>
8301<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8302 the return value, the referenced memory location is constant and
8303 unchanging.</p>
8304
8305</div>
8306
8307<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8308<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8309 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8310</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8311
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8312<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8313
8314<h5>Syntax:</h5>
8315<pre>
8316 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8317</pre>
8318
8319<h5>Overview:</h5>
8320<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8321 a memory object are mutable.</p>
8322
8323<h5>Arguments:</h5>
8324<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8325 The second argument is a constant integer representing the size of the
8326 object, or -1 if it is variable sized and the third argument is a pointer
8327 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8328
8329<h5>Semantics:</h5>
8330<p>This intrinsic indicates that the memory is mutable again.</p>
8331
8332</div>
8333
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8334</div>
8335
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8336<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8337<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8338 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8339</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8340
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8341<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8342
8343<p>This class of intrinsics is designed to be generic and has no specific
8344 purpose.</p>
8345
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8346<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8347<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8348 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8349</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8350
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8351<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8352
8353<h5>Syntax:</h5>
8354<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8355 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]8356</pre>
8357
8358<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8359<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8360
8361<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8362<p>The first argument is a pointer to a value, the second is a pointer to a
8363 global string, the third is a pointer to a global string which is the source
8364 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8365
8366<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8367<p>This intrinsic allows annotation of local variables with arbitrary strings.
8368 This can be useful for special purpose optimizations that want to look for
8369 these annotations. These have no other defined use, they are ignored by code
8370 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8371
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8372</div>
8373
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8374<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8375<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]8376 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8377</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8378
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8379<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8380
8381<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8382<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8383 any integer bit width.</p>
8384
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8385<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8386 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8387 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8388 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8389 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8390 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]8391</pre>
8392
8393<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8394<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8395
8396<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8397<p>The first argument is an integer value (result of some expression), the
8398 second is a pointer to a global string, the third is a pointer to a global
8399 string which is the source file name, and the last argument is the line
8400 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8401
8402<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8403<p>This intrinsic allows annotations to be put on arbitrary expressions with
8404 arbitrary strings. This can be useful for special purpose optimizations that
8405 want to look for these annotations. These have no other defined use, they
8406 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8407
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8408</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8409
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8410<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8411<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8412 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8413</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8414
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8415<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8416
8417<h5>Syntax:</h5>
8418<pre>
8419 declare void @llvm.trap()
8420</pre>
8421
8422<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8423<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8424
8425<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8426<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8427
8428<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8429<p>This intrinsics is lowered to the target dependent trap instruction. If the
8430 target does not have a trap instruction, this intrinsic will be lowered to
8431 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8432
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8433</div>
8434
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8435<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8436<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]8437 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8438</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8439
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8440<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8441
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8442<h5>Syntax:</h5>
8443<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8444 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8445</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8446
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8447<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8448<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8449 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8450 ensure that it is placed on the stack before local variables.</p>
8451
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8452<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8453<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8454 arguments. The first argument is the value loaded from the stack
8455 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8456 that has enough space to hold the value of the guard.</p>
8457
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8458<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8459<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8460 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8461 stack. This is to ensure that if a local variable on the stack is
8462 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8463 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8464 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8465 function.</p>
8466
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8467</div>
8468
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8469<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8470<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8471 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8472</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8473
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8474<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8475
8476<h5>Syntax:</h5>
8477<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8478 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8479 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8480</pre>
8481
8482<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8483<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8484 the optimizers to determine at compile time whether a) an operation (like
8485 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8486 runtime check for overflow isn't necessary. An object in this context means
8487 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8488
8489<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8490<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8491 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8492 is a boolean 0 or 1. This argument determines whether you want the
8493 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]8494 1, variables are not allowed.</p>
8495
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8496<h5>Semantics:</h5>
8497<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8498 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8499 depending on the <tt>type</tt> argument, if the size cannot be determined at
8500 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8501
8502</div>
8503
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8504</div>
8505
8506</div>
8507
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8508<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8509<hr>
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8516 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8517 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
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