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gerrit-public.fairphone.software / toolchain / llvm-project / f12e4e914be0062b84025a00ea2659ec7b70be96 / . / 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">
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Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
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11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]28 <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]29 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
30 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
31 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
32 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
33 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
35 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner80d73c72009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]56 <li><a href="#memmodel">Memory Model for Concurrent Operations</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]57 </ol>
58 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]59 <li><a href="#typesystem">Type System</a>
60 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]62 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]63 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]64 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]65 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]66 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]67 <li><a href="#t_void">Void Type</a></li>
68 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]69 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]70 </ol>
71 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]72 <li><a href="#t_derived">Derived Types</a>
73 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]74 <li><a href="#t_aggregate">Aggregate Types</a>
75 <ol>
76 <li><a href="#t_array">Array Type</a></li>
77 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]78 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]79 <li><a href="#t_vector">Vector Type</a></li>
80 </ol>
81 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]82 <li><a href="#t_function">Function Type</a></li>
83 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
86 </ol>
87 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]88 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]89 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]90 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]91 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
93 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]94 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]95 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]96 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]97 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]98 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]99 <li><a href="#othervalues">Other Values</a>
100 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]101 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]102 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]103 </ol>
104 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]105 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
106 <ol>
107 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]108 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
109 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]110 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
111 Global Variable</a></li>
112 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
113 Global Variable</a></li>
114 </ol>
115 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]116 <li><a href="#instref">Instruction Reference</a>
117 <ol>
118 <li><a href="#terminators">Terminator Instructions</a>
119 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
121 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]122 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]123 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]124 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]126 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]127 </ol>
128 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]129 <li><a href="#binaryops">Binary Operations</a>
130 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]131 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]132 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]137 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
138 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
139 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]140 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
141 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
142 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]143 </ol>
144 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]145 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
146 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]147 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
148 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
149 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]150 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]151 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 </ol>
154 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]155 <li><a href="#vectorops">Vector Operations</a>
156 <ol>
157 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
158 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
159 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]160 </ol>
161 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]162 <li><a href="#aggregateops">Aggregate Operations</a>
163 <ol>
164 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
165 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
166 </ol>
167 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]168 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]169 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]170 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]171 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
172 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
173 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]174 </ol>
175 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]176 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]177 <ol>
178 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
179 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
180 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]183 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
184 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
185 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
186 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]187 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
188 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]189 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]190 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]191 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]192 <li><a href="#otherops">Other Operations</a>
193 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]194 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
195 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]196 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]197 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]198 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]199 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]200 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]201 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]202 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]203 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]204 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]205 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]206 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
207 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]208 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
209 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
210 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]211 </ol>
212 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]213 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
214 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]215 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
216 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
217 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]218 </ol>
219 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]220 <li><a href="#int_codegen">Code Generator Intrinsics</a>
221 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]222 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
223 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
224 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
225 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
226 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
227 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]228 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]229 </ol>
230 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]231 <li><a href="#int_libc">Standard C Library Intrinsics</a>
232 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]233 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]238 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]241 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]243 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]244 </ol>
245 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]246 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]247 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]248 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]249 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
250 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
251 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]252 </ol>
253 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]254 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
255 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]256 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
257 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
260 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]261 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]262 </ol>
263 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]264 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
265 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]266 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
267 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]268 </ol>
269 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]270 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]271 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]272 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]273 <ol>
274 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]275 </ol>
276 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]277 <li><a href="#int_atomics">Atomic intrinsics</a>
278 <ol>
279 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
280 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
281 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
282 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
283 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
284 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
285 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
286 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
287 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
288 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
289 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
290 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
291 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
292 </ol>
293 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]294 <li><a href="#int_memorymarkers">Memory Use Markers</a>
295 <ol>
296 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
297 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
298 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
299 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
300 </ol>
301 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]302 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]303 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]304 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]306 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]307 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]308 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.trap</tt>' Intrinsic</a></li>
310 <li><a href="#int_stackprotector">
311 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]312 <li><a href="#int_objectsize">
313 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]314 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]315 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]316 </ol>
317 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]318</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]319
320<div class="doc_author">
321 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
322 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]323</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]325<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]326<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]328
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]329<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]330
331<p>This document is a reference manual for the LLVM assembly language. LLVM is
332 a Static Single Assignment (SSA) based representation that provides type
333 safety, low-level operations, flexibility, and the capability of representing
334 'all' high-level languages cleanly. It is the common code representation
335 used throughout all phases of the LLVM compilation strategy.</p>
336
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]337</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]338
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]339<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]340<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]341<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]342
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]343<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]344
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]345<p>The LLVM code representation is designed to be used in three different forms:
346 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
347 for fast loading by a Just-In-Time compiler), and as a human readable
348 assembly language representation. This allows LLVM to provide a powerful
349 intermediate representation for efficient compiler transformations and
350 analysis, while providing a natural means to debug and visualize the
351 transformations. The three different forms of LLVM are all equivalent. This
352 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]354<p>The LLVM representation aims to be light-weight and low-level while being
355 expressive, typed, and extensible at the same time. It aims to be a
356 "universal IR" of sorts, by being at a low enough level that high-level ideas
357 may be cleanly mapped to it (similar to how microprocessors are "universal
358 IR's", allowing many source languages to be mapped to them). By providing
359 type information, LLVM can be used as the target of optimizations: for
360 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]361 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]362 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]364<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]365<h4>
366 <a name="wellformed">Well-Formedness</a>
367</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]368
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]369<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]371<p>It is important to note that this document describes 'well formed' LLVM
372 assembly language. There is a difference between what the parser accepts and
373 what is considered 'well formed'. For example, the following instruction is
374 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]376<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]377%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]378</pre>
379
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]380<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
381 LLVM infrastructure provides a verification pass that may be used to verify
382 that an LLVM module is well formed. This pass is automatically run by the
383 parser after parsing input assembly and by the optimizer before it outputs
384 bitcode. The violations pointed out by the verifier pass indicate bugs in
385 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]386
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]387</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]388
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]389</div>
390
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]391<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]392
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]393<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]394<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]395<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]396
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]397<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]398
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]399<p>LLVM identifiers come in two basic types: global and local. Global
400 identifiers (functions, global variables) begin with the <tt>'@'</tt>
401 character. Local identifiers (register names, types) begin with
402 the <tt>'%'</tt> character. Additionally, there are three different formats
403 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]404
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]405<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]406 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]407 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
408 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
409 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
410 other characters in their names can be surrounded with quotes. Special
411 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
412 ASCII code for the character in hexadecimal. In this way, any character
413 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]414
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]415 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]416 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]417
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]418 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]419 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]420</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]422<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]423 don't need to worry about name clashes with reserved words, and the set of
424 reserved words may be expanded in the future without penalty. Additionally,
425 unnamed identifiers allow a compiler to quickly come up with a temporary
426 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]427
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]428<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]429 languages. There are keywords for different opcodes
430 ('<tt><a href="#i_add">add</a></tt>',
431 '<tt><a href="#i_bitcast">bitcast</a></tt>',
432 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
433 ('<tt><a href="#t_void">void</a></tt>',
434 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
435 reserved words cannot conflict with variable names, because none of them
436 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]437
438<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]439 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]440
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]441<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]443<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]444%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]445</pre>
446
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]447<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]449<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]450%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]451</pre>
452
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]453<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]454
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]455<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]456%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
457%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]458%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459</pre>
460
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]461<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
462 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]463
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]464<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]466 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
468 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]469 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]470
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]471 <li>Unnamed temporaries are numbered sequentially</li>
472</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]473
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]474<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]475 demonstrating instructions, we will follow an instruction with a comment that
476 defines the type and name of value produced. Comments are shown in italic
477 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]478
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]479</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]480
481<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]482<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]483<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]484<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]485<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]486<h3>
487 <a name="modulestructure">Module Structure</a>
488</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]490<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]492<p>LLVM programs are composed of "Module"s, each of which is a translation unit
493 of the input programs. Each module consists of functions, global variables,
494 and symbol table entries. Modules may be combined together with the LLVM
495 linker, which merges function (and global variable) definitions, resolves
496 forward declarations, and merges symbol table entries. Here is an example of
497 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]498
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]499<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]500<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]501<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]503<i>; External declaration of the puts function</i>&nbsp;
504<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]505
506<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]507define i32 @main() { <i>; i32()* </i>&nbsp;
508 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
509 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]510
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]511 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
512 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
513 <a href="#i_ret">ret</a> i32 0&nbsp;
514}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]515
516<i>; Named metadata</i>
517!1 = metadata !{i32 41}
518!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]519</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]521<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]522 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]524 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
525 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]527<p>In general, a module is made up of a list of global values, where both
528 functions and global variables are global values. Global values are
529 represented by a pointer to a memory location (in this case, a pointer to an
530 array of char, and a pointer to a function), and have one of the
531 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]532
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]533</div>
534
535<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]536<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]537 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]538</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]539
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]540<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]541
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]542<p>All Global Variables and Functions have one of the following types of
543 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]544
545<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]547 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
548 by objects in the current module. In particular, linking code into a
549 module with an private global value may cause the private to be renamed as
550 necessary to avoid collisions. Because the symbol is private to the
551 module, all references can be updated. This doesn't show up in any symbol
552 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]553
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]555 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
556 assembler and evaluated by the linker. Unlike normal strong symbols, they
557 are removed by the linker from the final linked image (executable or
558 dynamic library).</dd>
559
560 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
561 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
562 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
563 linker. The symbols are removed by the linker from the final linked image
564 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]565
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]566 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
567 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
568 of the object is not taken. For instance, functions that had an inline
569 definition, but the compiler decided not to inline it. Note,
570 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
571 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
572 visibility. The symbols are removed by the linker from the final linked
573 image (executable or dynamic library).</dd>
574
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]575 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]576 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]577 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
578 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]579
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]581 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]582 into the object file corresponding to the LLVM module. They exist to
583 allow inlining and other optimizations to take place given knowledge of
584 the definition of the global, which is known to be somewhere outside the
585 module. Globals with <tt>available_externally</tt> linkage are allowed to
586 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
587 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]588
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]589 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]590 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]591 the same name when linkage occurs. This can be used to implement
592 some forms of inline functions, templates, or other code which must be
593 generated in each translation unit that uses it, but where the body may
594 be overridden with a more definitive definition later. Unreferenced
595 <tt>linkonce</tt> globals are allowed to be discarded. Note that
596 <tt>linkonce</tt> linkage does not actually allow the optimizer to
597 inline the body of this function into callers because it doesn't know if
598 this definition of the function is the definitive definition within the
599 program or whether it will be overridden by a stronger definition.
600 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
601 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]602
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]603 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]604 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
605 <tt>linkonce</tt> linkage, except that unreferenced globals with
606 <tt>weak</tt> linkage may not be discarded. This is used for globals that
607 are declared "weak" in C source code.</dd>
608
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]610 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
611 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
612 global scope.
613 Symbols with "<tt>common</tt>" linkage are merged in the same way as
614 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]615 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]616 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]617 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
618 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]619
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]620
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]621 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]622 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]623 pointer to array type. When two global variables with appending linkage
624 are linked together, the two global arrays are appended together. This is
625 the LLVM, typesafe, equivalent of having the system linker append together
626 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]627
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]628 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]629 <dd>The semantics of this linkage follow the ELF object file model: the symbol
630 is weak until linked, if not linked, the symbol becomes null instead of
631 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]632
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]633 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
634 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]635 <dd>Some languages allow differing globals to be merged, such as two functions
636 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]637 that only equivalent globals are ever merged (the "one definition rule"
638 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]639 and <tt>weak_odr</tt> linkage types to indicate that the global will only
640 be merged with equivalent globals. These linkage types are otherwise the
641 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]642
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]643 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]644 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]645 visible, meaning that it participates in linkage and can be used to
646 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]647</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]648
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]649<p>The next two types of linkage are targeted for Microsoft Windows platform
650 only. They are designed to support importing (exporting) symbols from (to)
651 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]653<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]654 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]655 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]656 or variable via a global pointer to a pointer that is set up by the DLL
657 exporting the symbol. On Microsoft Windows targets, the pointer name is
658 formed by combining <code>__imp_</code> and the function or variable
659 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]660
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]661 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]662 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]663 pointer to a pointer in a DLL, so that it can be referenced with the
664 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
665 name is formed by combining <code>__imp_</code> and the function or
666 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]667</dl>
668
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]669<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
670 another module defined a "<tt>.LC0</tt>" variable and was linked with this
671 one, one of the two would be renamed, preventing a collision. Since
672 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
673 declarations), they are accessible outside of the current module.</p>
674
675<p>It is illegal for a function <i>declaration</i> to have any linkage type
676 other than "externally visible", <tt>dllimport</tt>
677 or <tt>extern_weak</tt>.</p>
678
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]679<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]680 or <tt>weak_odr</tt> linkages.</p>
681
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]682</div>
683
684<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]685<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]686 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]687</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]688
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]689<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]690
691<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]692 and <a href="#i_invoke">invokes</a> can all have an optional calling
693 convention specified for the call. The calling convention of any pair of
694 dynamic caller/callee must match, or the behavior of the program is
695 undefined. The following calling conventions are supported by LLVM, and more
696 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]697
698<dl>
699 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]700 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]701 specified) matches the target C calling conventions. This calling
702 convention supports varargs function calls and tolerates some mismatch in
703 the declared prototype and implemented declaration of the function (as
704 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]705
706 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]708 (e.g. by passing things in registers). This calling convention allows the
709 target to use whatever tricks it wants to produce fast code for the
710 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]711 (Application Binary Interface).
712 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]713 when this or the GHC convention is used.</a> This calling convention
714 does not support varargs and requires the prototype of all callees to
715 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]716
717 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]718 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]719 as possible under the assumption that the call is not commonly executed.
720 As such, these calls often preserve all registers so that the call does
721 not break any live ranges in the caller side. This calling convention
722 does not support varargs and requires the prototype of all callees to
723 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]724
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]725 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
726 <dd>This calling convention has been implemented specifically for use by the
727 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
728 It passes everything in registers, going to extremes to achieve this by
729 disabling callee save registers. This calling convention should not be
730 used lightly but only for specific situations such as an alternative to
731 the <em>register pinning</em> performance technique often used when
732 implementing functional programming languages.At the moment only X86
733 supports this convention and it has the following limitations:
734 <ul>
735 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
736 floating point types are supported.</li>
737 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
738 6 floating point parameters.</li>
739 </ul>
740 This calling convention supports
741 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
742 requires both the caller and callee are using it.
743 </dd>
744
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]745 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]746 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]747 target-specific calling conventions to be used. Target specific calling
748 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]749</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]750
751<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]752 support Pascal conventions or any other well-known target-independent
753 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]754
755</div>
756
757<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]758<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]759 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]760</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]761
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]762<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]763
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]764<p>All Global Variables and Functions have one of the following visibility
765 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]766
767<dl>
768 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]769 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]770 that the declaration is visible to other modules and, in shared libraries,
771 means that the declared entity may be overridden. On Darwin, default
772 visibility means that the declaration is visible to other modules. Default
773 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]774
775 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]776 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]777 object if they are in the same shared object. Usually, hidden visibility
778 indicates that the symbol will not be placed into the dynamic symbol
779 table, so no other module (executable or shared library) can reference it
780 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]781
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]782 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]783 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]784 the dynamic symbol table, but that references within the defining module
785 will bind to the local symbol. That is, the symbol cannot be overridden by
786 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]787</dl>
788
789</div>
790
791<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]792<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]793 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]794</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]795
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]796<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]797
798<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]799 it easier to read the IR and make the IR more condensed (particularly when
800 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]801
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]802<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]803%mytype = type { %mytype*, i32 }
804</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]805
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]806<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]807 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]808 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]809
810<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]811 and that you can therefore specify multiple names for the same type. This
812 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
813 uses structural typing, the name is not part of the type. When printing out
814 LLVM IR, the printer will pick <em>one name</em> to render all types of a
815 particular shape. This means that if you have code where two different
816 source types end up having the same LLVM type, that the dumper will sometimes
817 print the "wrong" or unexpected type. This is an important design point and
818 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]819
820</div>
821
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]822<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]823<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]824 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]825</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]826
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]827<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]828
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]829<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]830 instead of run-time. Global variables may optionally be initialized, may
831 have an explicit section to be placed in, and may have an optional explicit
832 alignment specified. A variable may be defined as "thread_local", which
833 means that it will not be shared by threads (each thread will have a
834 separated copy of the variable). A variable may be defined as a global
835 "constant," which indicates that the contents of the variable
836 will <b>never</b> be modified (enabling better optimization, allowing the
837 global data to be placed in the read-only section of an executable, etc).
838 Note that variables that need runtime initialization cannot be marked
839 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]840
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]841<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
842 constant, even if the final definition of the global is not. This capability
843 can be used to enable slightly better optimization of the program, but
844 requires the language definition to guarantee that optimizations based on the
845 'constantness' are valid for the translation units that do not include the
846 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]847
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]848<p>As SSA values, global variables define pointer values that are in scope
849 (i.e. they dominate) all basic blocks in the program. Global variables
850 always define a pointer to their "content" type because they describe a
851 region of memory, and all memory objects in LLVM are accessed through
852 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]853
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]854<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
855 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]856 like this can be merged with other constants if they have the same
857 initializer. Note that a constant with significant address <em>can</em>
858 be merged with a <tt>unnamed_addr</tt> constant, the result being a
859 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]860
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]861<p>A global variable may be declared to reside in a target-specific numbered
862 address space. For targets that support them, address spaces may affect how
863 optimizations are performed and/or what target instructions are used to
864 access the variable. The default address space is zero. The address space
865 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]866
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]867<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]868 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]869
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]870<p>An explicit alignment may be specified for a global, which must be a power
871 of 2. If not present, or if the alignment is set to zero, the alignment of
872 the global is set by the target to whatever it feels convenient. If an
873 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]874 alignment. Targets and optimizers are not allowed to over-align the global
875 if the global has an assigned section. In this case, the extra alignment
876 could be observable: for example, code could assume that the globals are
877 densely packed in their section and try to iterate over them as an array,
878 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]879
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]880<p>For example, the following defines a global in a numbered address space with
881 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]882
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]883<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]884@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]885</pre>
886
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]887</div>
888
889
890<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]891<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]892 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]893</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]894
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]895<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]896
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]897<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]898 optional <a href="#linkage">linkage type</a>, an optional
899 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]900 <a href="#callingconv">calling convention</a>,
901 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]902 <a href="#paramattrs">parameter attribute</a> for the return type, a function
903 name, a (possibly empty) argument list (each with optional
904 <a href="#paramattrs">parameter attributes</a>), optional
905 <a href="#fnattrs">function attributes</a>, an optional section, an optional
906 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
907 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]908
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]909<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
910 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]911 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]912 <a href="#callingconv">calling convention</a>,
913 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]914 <a href="#paramattrs">parameter attribute</a> for the return type, a function
915 name, a possibly empty list of arguments, an optional alignment, and an
916 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]917
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]918<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]919 (Control Flow Graph) for the function. Each basic block may optionally start
920 with a label (giving the basic block a symbol table entry), contains a list
921 of instructions, and ends with a <a href="#terminators">terminator</a>
922 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]923
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]924<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]925 executed on entrance to the function, and it is not allowed to have
926 predecessor basic blocks (i.e. there can not be any branches to the entry
927 block of a function). Because the block can have no predecessors, it also
928 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]929
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]930<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]931 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]932
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]933<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]934 the alignment is set to zero, the alignment of the function is set by the
935 target to whatever it feels convenient. If an explicit alignment is
936 specified, the function is forced to have at least that much alignment. All
937 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]938
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]939<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
940 be significant and two identical functions can be merged</p>.
941
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]942<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]943<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]944define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]945 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
946 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
947 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
948 [<a href="#gc">gc</a>] { ... }
949</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]950
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]951</div>
952
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]953<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]954<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]955 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]956</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]957
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]958<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]959
960<p>Aliases act as "second name" for the aliasee value (which can be either
961 function, global variable, another alias or bitcast of global value). Aliases
962 may have an optional <a href="#linkage">linkage type</a>, and an
963 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]964
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]965<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]966<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]967@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]968</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]969
970</div>
971
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]972<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]973<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]974 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]975</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]976
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]977<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]978
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]979<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]980 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]981 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]982
983<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]984<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]985; Some unnamed metadata nodes, which are referenced by the named metadata.
986!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]987!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]988!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]989; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]990!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]991</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]992
993</div>
994
995<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]996<h3>
997 <a name="paramattrs">Parameter Attributes</a>
998</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]999
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1000<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1001
1002<p>The return type and each parameter of a function type may have a set of
1003 <i>parameter attributes</i> associated with them. Parameter attributes are
1004 used to communicate additional information about the result or parameters of
1005 a function. Parameter attributes are considered to be part of the function,
1006 not of the function type, so functions with different parameter attributes
1007 can have the same function type.</p>
1008
1009<p>Parameter attributes are simple keywords that follow the type specified. If
1010 multiple parameter attributes are needed, they are space separated. For
1011 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1012
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1013<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1014declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1015declare i32 @atoi(i8 zeroext)
1016declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1017</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1018
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1019<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1020 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1021
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1022<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1023
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1024<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1025 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1026 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1027 should be zero-extended to the extent required by the target's ABI (which
1028 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1029 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1030
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1033 should be sign-extended to the extent required by the target's ABI (which
1034 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1035 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1036
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1037 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This indicates that this parameter or return value should be treated in a
1039 special target-dependent fashion during while emitting code for a function
1040 call or return (usually, by putting it in a register as opposed to memory,
1041 though some targets use it to distinguish between two different kinds of
1042 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1043
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1044 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1045 <dd><p>This indicates that the pointer parameter should really be passed by
1046 value to the function. The attribute implies that a hidden copy of the
1047 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1048 is made between the caller and the callee, so the callee is unable to
1049 modify the value in the callee. This attribute is only valid on LLVM
1050 pointer arguments. It is generally used to pass structs and arrays by
1051 value, but is also valid on pointers to scalars. The copy is considered
1052 to belong to the caller not the callee (for example,
1053 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1054 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1055 values.</p>
1056
1057 <p>The byval attribute also supports specifying an alignment with
1058 the align attribute. It indicates the alignment of the stack slot to
1059 form and the known alignment of the pointer specified to the call site. If
1060 the alignment is not specified, then the code generator makes a
1061 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1062
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1063 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1064 <dd>This indicates that the pointer parameter specifies the address of a
1065 structure that is the return value of the function in the source program.
1066 This pointer must be guaranteed by the caller to be valid: loads and
1067 stores to the structure may be assumed by the callee to not to trap. This
1068 may only be applied to the first parameter. This is not a valid attribute
1069 for return values. </dd>
1070
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1071 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1072 <dd>This indicates that pointer values
1073 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1074 value do not alias pointer values which are not <i>based</i> on it,
1075 ignoring certain "irrelevant" dependencies.
1076 For a call to the parent function, dependencies between memory
1077 references from before or after the call and from those during the call
1078 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1079 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1080 The caller shares the responsibility with the callee for ensuring that
1081 these requirements are met.
1082 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1083 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1084<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1085 Note that this definition of <tt>noalias</tt> is intentionally
1086 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1087 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1088<br>
1089 For function return values, C99's <tt>restrict</tt> is not meaningful,
1090 while LLVM's <tt>noalias</tt> is.
1091 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1092
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1093 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1094 <dd>This indicates that the callee does not make any copies of the pointer
1095 that outlive the callee itself. This is not a valid attribute for return
1096 values.</dd>
1097
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1098 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This indicates that the pointer parameter can be excised using the
1100 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1101 attribute for return values.</dd>
1102</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1103
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1104</div>
1105
1106<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1107<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1108 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1109</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1110
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1111<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1112
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1113<p>Each function may specify a garbage collector name, which is simply a
1114 string:</p>
1115
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1116<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1117define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1118</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1119
1120<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1121 collector which will cause the compiler to alter its output in order to
1122 support the named garbage collection algorithm.</p>
1123
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1124</div>
1125
1126<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1127<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1128 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1129</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1130
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1131<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1132
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1133<p>Function attributes are set to communicate additional information about a
1134 function. Function attributes are considered to be part of the function, not
1135 of the function type, so functions with different parameter attributes can
1136 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1137
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1138<p>Function attributes are simple keywords that follow the type specified. If
1139 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1140
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1141<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1142define void @f() noinline { ... }
1143define void @f() alwaysinline { ... }
1144define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1145define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1146</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1147
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1148<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1149 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1150 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1151 the backend should forcibly align the stack pointer. Specify the
1152 desired alignment, which must be a power of two, in parentheses.
1153
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1154 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1155 <dd>This attribute indicates that the inliner should attempt to inline this
1156 function into callers whenever possible, ignoring any active inlining size
1157 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1158
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1159 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1160 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1161 meaning the function can be patched and/or hooked even while it is
1162 loaded into memory. On x86, the function prologue will be preceded
1163 by six bytes of padding and will begin with a two-byte instruction.
1164 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1165 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1166
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1167 <dt><tt><b>nonlazybind</b></tt></dt>
1168 <dd>This attribute suppresses lazy symbol binding for the function. This
1169 may make calls to the function faster, at the cost of extra program
1170 startup time if the function is not called during program startup.</dd>
1171
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1172 <dt><tt><b>inlinehint</b></tt></dt>
1173 <dd>This attribute indicates that the source code contained a hint that inlining
1174 this function is desirable (such as the "inline" keyword in C/C++). It
1175 is just a hint; it imposes no requirements on the inliner.</dd>
1176
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1177 <dt><tt><b>naked</b></tt></dt>
1178 <dd>This attribute disables prologue / epilogue emission for the function.
1179 This can have very system-specific consequences.</dd>
1180
1181 <dt><tt><b>noimplicitfloat</b></tt></dt>
1182 <dd>This attributes disables implicit floating point instructions.</dd>
1183
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1184 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1185 <dd>This attribute indicates that the inliner should never inline this
1186 function in any situation. This attribute may not be used together with
1187 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1188
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1189 <dt><tt><b>noredzone</b></tt></dt>
1190 <dd>This attribute indicates that the code generator should not use a red
1191 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1192
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1193 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1194 <dd>This function attribute indicates that the function never returns
1195 normally. This produces undefined behavior at runtime if the function
1196 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1197
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This function attribute indicates that the function never returns with an
1200 unwind or exceptional control flow. If the function does unwind, its
1201 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1202
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1203 <dt><tt><b>optsize</b></tt></dt>
1204 <dd>This attribute suggests that optimization passes and code generator passes
1205 make choices that keep the code size of this function low, and otherwise
1206 do optimizations specifically to reduce code size.</dd>
1207
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1208 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1209 <dd>This attribute indicates that the function computes its result (or decides
1210 to unwind an exception) based strictly on its arguments, without
1211 dereferencing any pointer arguments or otherwise accessing any mutable
1212 state (e.g. memory, control registers, etc) visible to caller functions.
1213 It does not write through any pointer arguments
1214 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1215 changes any state visible to callers. This means that it cannot unwind
1216 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1217 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1218
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1219 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1220 <dd>This attribute indicates that the function does not write through any
1221 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1222 arguments) or otherwise modify any state (e.g. memory, control registers,
1223 etc) visible to caller functions. It may dereference pointer arguments
1224 and read state that may be set in the caller. A readonly function always
1225 returns the same value (or unwinds an exception identically) when called
1226 with the same set of arguments and global state. It cannot unwind an
1227 exception by calling the <tt>C++</tt> exception throwing methods, but may
1228 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1229
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1230 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1231 <dd>This attribute indicates that the function should emit a stack smashing
1232 protector. It is in the form of a "canary"&mdash;a random value placed on
1233 the stack before the local variables that's checked upon return from the
1234 function to see if it has been overwritten. A heuristic is used to
1235 determine if a function needs stack protectors or not.<br>
1236<br>
1237 If a function that has an <tt>ssp</tt> attribute is inlined into a
1238 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1239 function will have an <tt>ssp</tt> attribute.</dd>
1240
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1241 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1242 <dd>This attribute indicates that the function should <em>always</em> emit a
1243 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1244 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1245<br>
1246 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1247 function that doesn't have an <tt>sspreq</tt> attribute or which has
1248 an <tt>ssp</tt> attribute, then the resulting function will have
1249 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1250</dl>
1251
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1252</div>
1253
1254<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1255<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1256 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1257</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1258
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1259<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1260
1261<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1262 the GCC "file scope inline asm" blocks. These blocks are internally
1263 concatenated by LLVM and treated as a single unit, but may be separated in
1264 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1265
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1266<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1267module asm "inline asm code goes here"
1268module asm "more can go here"
1269</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1270
1271<p>The strings can contain any character by escaping non-printable characters.
1272 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1273 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1274
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1275<p>The inline asm code is simply printed to the machine code .s file when
1276 assembly code is generated.</p>
1277
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1278</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1279
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1280<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1281<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1282 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1283</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1284
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1285<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1286
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1287<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1288 data is to be laid out in memory. The syntax for the data layout is
1289 simply:</p>
1290
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1291<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1292target datalayout = "<i>layout specification</i>"
1293</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1294
1295<p>The <i>layout specification</i> consists of a list of specifications
1296 separated by the minus sign character ('-'). Each specification starts with
1297 a letter and may include other information after the letter to define some
1298 aspect of the data layout. The specifications accepted are as follows:</p>
1299
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1300<dl>
1301 <dt><tt>E</tt></dt>
1302 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1303 bits with the most significance have the lowest address location.</dd>
1304
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1305 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1306 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1307 the bits with the least significance have the lowest address
1308 location.</dd>
1309
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1310 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1311 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1312 <i>preferred</i> alignments. All sizes are in bits. Specifying
1313 the <i>pref</i> alignment is optional. If omitted, the
1314 preceding <tt>:</tt> should be omitted too.</dd>
1315
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1316 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1317 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1318 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1319
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1320 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1321 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1322 <i>size</i>.</dd>
1323
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1324 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1325 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1326 <i>size</i>. Only values of <i>size</i> that are supported by the target
1327 will work. 32 (float) and 64 (double) are supported on all targets;
1328 80 or 128 (different flavors of long double) are also supported on some
1329 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1330
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1331 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1332 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1333 <i>size</i>.</dd>
1334
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1335 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1336 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1337 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1338
1339 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1340 <dd>This specifies a set of native integer widths for the target CPU
1341 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1342 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1343 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1344 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1345</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1346
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1347<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1348 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1349 specifications in the <tt>datalayout</tt> keyword. The default specifications
1350 are given in this list:</p>
1351
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1352<ul>
1353 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1354 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1355 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1356 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1357 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1358 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1359 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1360 alignment of 64-bits</li>
1361 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1362 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1363 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1364 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1365 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1366 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1367</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1368
1369<p>When LLVM is determining the alignment for a given type, it uses the
1370 following rules:</p>
1371
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1372<ol>
1373 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1374 specification is used.</li>
1375
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1376 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1377 smallest integer type that is larger than the bitwidth of the sought type
1378 is used. If none of the specifications are larger than the bitwidth then
1379 the the largest integer type is used. For example, given the default
1380 specifications above, the i7 type will use the alignment of i8 (next
1381 largest) while both i65 and i256 will use the alignment of i64 (largest
1382 specified).</li>
1383
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1384 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1385 largest vector type that is smaller than the sought vector type will be
1386 used as a fall back. This happens because &lt;128 x double&gt; can be
1387 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1388</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1389
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1390</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1391
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1392<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1393<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1394 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1395</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1396
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1397<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1398
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1399<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1400with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1401is undefined. Pointer values are associated with address ranges
1402according to the following rules:</p>
1403
1404<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1405 <li>A pointer value is associated with the addresses associated with
1406 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1407 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1408 range of the variable's storage.</li>
1409 <li>The result value of an allocation instruction is associated with
1410 the address range of the allocated storage.</li>
1411 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1412 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1413 <li>An integer constant other than zero or a pointer value returned
1414 from a function not defined within LLVM may be associated with address
1415 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1416 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1417 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1418</ul>
1419
1420<p>A pointer value is <i>based</i> on another pointer value according
1421 to the following rules:</p>
1422
1423<ul>
1424 <li>A pointer value formed from a
1425 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1426 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1427 <li>The result value of a
1428 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1429 of the <tt>bitcast</tt>.</li>
1430 <li>A pointer value formed by an
1431 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1432 pointer values that contribute (directly or indirectly) to the
1433 computation of the pointer's value.</li>
1434 <li>The "<i>based</i> on" relationship is transitive.</li>
1435</ul>
1436
1437<p>Note that this definition of <i>"based"</i> is intentionally
1438 similar to the definition of <i>"based"</i> in C99, though it is
1439 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1440
1441<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1442<tt><a href="#i_load">load</a></tt> merely indicates the size and
1443alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1444interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1445<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1446and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1447
1448<p>Consequently, type-based alias analysis, aka TBAA, aka
1449<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1450LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1451additional information which specialized optimization passes may use
1452to implement type-based alias analysis.</p>
1453
1454</div>
1455
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1456<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1457<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1458 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1459</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1460
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1461<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1462
1463<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1464href="#i_store"><tt>store</tt></a>s, and <a
1465href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1466The optimizers must not change the number of volatile operations or change their
1467order of execution relative to other volatile operations. The optimizers
1468<i>may</i> change the order of volatile operations relative to non-volatile
1469operations. This is not Java's "volatile" and has no cross-thread
1470synchronization behavior.</p>
1471
1472</div>
1473
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1474<!-- ======================================================================= -->
1475<h3>
1476 <a name="memmodel">Memory Model for Concurrent Operations</a>
1477</h3>
1478
1479<div>
1480
1481<p>The LLVM IR does not define any way to start parallel threads of execution
1482or to register signal handlers. Nonetheless, there are platform-specific
1483ways to create them, and we define LLVM IR's behavior in their presence. This
1484model is inspired by the C++0x memory model.</p>
1485
1486<p>We define a <i>happens-before</i> partial order as the least partial order
1487that</p>
1488<ul>
1489 <li>Is a superset of single-thread program order, and</li>
1490 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1491 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1492 by platform-specific techniques, like pthread locks, thread
1493 creation, thread joining, etc., and by the atomic operations described
1494 in the <a href="#int_atomics">Atomic intrinsics</a> section.</li>
1495</ul>
1496
1497<p>Note that program order does not introduce <i>happens-before</i> edges
1498between a thread and signals executing inside that thread.</p>
1499
1500<p>Every (defined) read operation (load instructions, memcpy, atomic
1501loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1502(defined) write operations (store instructions, atomic
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame^]1503stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1504initialized globals are considered to have a write of the initializer which is
1505atomic and happens before any other read or write of the memory in question.
1506For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1507any write to the same byte, except:</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1508
1509<ul>
1510 <li>If <var>write<sub>1</sub></var> happens before
1511 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1512 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame^]1513 does not see <var>write<sub>1</sub></var>.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1514 <li>If <var>R<sub>byte</sub></var> happens before <var>write<sub>3</var>,
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame^]1515 then <var>R<sub>byte</sub></var> does not see
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1516 <var>write<sub>3</sub></var>.
1517</ul>
1518
1519<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1520<ul>
1521 <li>If there is no write to the same byte that happens before
1522 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1523 <tt>undef</tt> for that byte.
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame^]1524 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1525 <var>R<sub>byte</sub></var> returns the value written by that
1526 write.</li>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame^]1527 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1528 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
1529 values written. See the <a href="#int_atomics">Atomic intrinsics</a>
1530 section for additional guarantees on how the choice is made.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1531 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1532</ul>
1533
1534<p><var>R</var> returns the value composed of the series of bytes it read.
1535This implies that some bytes within the value may be <tt>undef</tt>
1536<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1537defines the semantics of the operation; it doesn't mean that targets will
1538emit more than one instruction to read the series of bytes.</p>
1539
1540<p>Note that in cases where none of the atomic intrinsics are used, this model
1541places only one restriction on IR transformations on top of what is required
1542for single-threaded execution: introducing a store to a byte which might not
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame^]1543otherwise be stored to can introduce undefined behavior. (Specifically, in
1544the case where another thread might write to and read from an address,
1545introducing a store can change a load that may see exactly one write into
1546a load that may see multiple writes.)</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1547
1548<!-- FIXME: This model assumes all targets where concurrency is relevant have
1549a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1550none of the backends currently in the tree fall into this category; however,
1551there might be targets which care. If there are, we want a paragraph
1552like the following:
1553
1554Targets may specify that stores narrower than a certain width are not
1555available; on such a target, for the purposes of this model, treat any
1556non-atomic write with an alignment or width less than the minimum width
1557as if it writes to the relevant surrounding bytes.
1558-->
1559
1560</div>
1561
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1562</div>
1563
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1564<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1565<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1566<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1567
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1568<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1569
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1570<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1571 intermediate representation. Being typed enables a number of optimizations
1572 to be performed on the intermediate representation directly, without having
1573 to do extra analyses on the side before the transformation. A strong type
1574 system makes it easier to read the generated code and enables novel analyses
1575 and transformations that are not feasible to perform on normal three address
1576 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1577
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1578<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1579<h3>
1580 <a name="t_classifications">Type Classifications</a>
1581</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1582
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1583<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1584
1585<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1586
1587<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1588 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1589 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1590 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1591 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1592 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1593 </tr>
1594 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1595 <td><a href="#t_floating">floating point</a></td>
1596 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1597 </tr>
1598 <tr>
1599 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1600 <td><a href="#t_integer">integer</a>,
1601 <a href="#t_floating">floating point</a>,
1602 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1603 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1604 <a href="#t_struct">structure</a>,
1605 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1606 <a href="#t_label">label</a>,
1607 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1608 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1609 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1610 <tr>
1611 <td><a href="#t_primitive">primitive</a></td>
1612 <td><a href="#t_label">label</a>,
1613 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1614 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1615 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1616 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1617 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1618 </tr>
1619 <tr>
1620 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1621 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1622 <a href="#t_function">function</a>,
1623 <a href="#t_pointer">pointer</a>,
1624 <a href="#t_struct">structure</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1625 <a href="#t_vector">vector</a>,
1626 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1627 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1628 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1629 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1630</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1631
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1632<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1633 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1634 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1635
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1636</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1637
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1638<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1639<h3>
1640 <a name="t_primitive">Primitive Types</a>
1641</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1642
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1643<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1644
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1645<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1646 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1647
1648<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1649<h4>
1650 <a name="t_integer">Integer Type</a>
1651</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1652
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1653<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1654
1655<h5>Overview:</h5>
1656<p>The integer type is a very simple type that simply specifies an arbitrary
1657 bit width for the integer type desired. Any bit width from 1 bit to
1658 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1659
1660<h5>Syntax:</h5>
1661<pre>
1662 iN
1663</pre>
1664
1665<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1666 value.</p>
1667
1668<h5>Examples:</h5>
1669<table class="layout">
1670 <tr class="layout">
1671 <td class="left"><tt>i1</tt></td>
1672 <td class="left">a single-bit integer.</td>
1673 </tr>
1674 <tr class="layout">
1675 <td class="left"><tt>i32</tt></td>
1676 <td class="left">a 32-bit integer.</td>
1677 </tr>
1678 <tr class="layout">
1679 <td class="left"><tt>i1942652</tt></td>
1680 <td class="left">a really big integer of over 1 million bits.</td>
1681 </tr>
1682</table>
1683
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1684</div>
1685
1686<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1687<h4>
1688 <a name="t_floating">Floating Point Types</a>
1689</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1690
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1691<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1692
1693<table>
1694 <tbody>
1695 <tr><th>Type</th><th>Description</th></tr>
1696 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1697 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1698 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1699 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1700 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1701 </tbody>
1702</table>
1703
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1704</div>
1705
1706<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1707<h4>
1708 <a name="t_x86mmx">X86mmx Type</a>
1709</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1710
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1711<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1712
1713<h5>Overview:</h5>
1714<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>
1715
1716<h5>Syntax:</h5>
1717<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1718 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1719</pre>
1720
1721</div>
1722
1723<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1724<h4>
1725 <a name="t_void">Void Type</a>
1726</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1727
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1728<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1729
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1730<h5>Overview:</h5>
1731<p>The void type does not represent any value and has no size.</p>
1732
1733<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1734<pre>
1735 void
1736</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1737
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1738</div>
1739
1740<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1741<h4>
1742 <a name="t_label">Label Type</a>
1743</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1744
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1745<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1746
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1747<h5>Overview:</h5>
1748<p>The label type represents code labels.</p>
1749
1750<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1751<pre>
1752 label
1753</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1754
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1755</div>
1756
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1757<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1758<h4>
1759 <a name="t_metadata">Metadata Type</a>
1760</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1761
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1762<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1763
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1764<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1765<p>The metadata type represents embedded metadata. No derived types may be
1766 created from metadata except for <a href="#t_function">function</a>
1767 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1768
1769<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1770<pre>
1771 metadata
1772</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1773
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1774</div>
1775
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1776</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1777
1778<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1779<h3>
1780 <a name="t_derived">Derived Types</a>
1781</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1782
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1783<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1784
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1785<p>The real power in LLVM comes from the derived types in the system. This is
1786 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1787 useful types. Each of these types contain one or more element types which
1788 may be a primitive type, or another derived type. For example, it is
1789 possible to have a two dimensional array, using an array as the element type
1790 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1791
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1792</div>
1793
1794
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1795<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1796<h4>
1797 <a name="t_aggregate">Aggregate Types</a>
1798</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1799
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1800<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1801
1802<p>Aggregate Types are a subset of derived types that can contain multiple
1803 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1804 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1805 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1806
1807</div>
1808
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1809<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1810<h4>
1811 <a name="t_array">Array Type</a>
1812</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1813
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1814<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1815
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1816<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1817<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1818 sequentially in memory. The array type requires a size (number of elements)
1819 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1820
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1821<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1822<pre>
1823 [&lt;# elements&gt; x &lt;elementtype&gt;]
1824</pre>
1825
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1826<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1827 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1828
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1829<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1830<table class="layout">
1831 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1832 <td class="left"><tt>[40 x i32]</tt></td>
1833 <td class="left">Array of 40 32-bit integer values.</td>
1834 </tr>
1835 <tr class="layout">
1836 <td class="left"><tt>[41 x i32]</tt></td>
1837 <td class="left">Array of 41 32-bit integer values.</td>
1838 </tr>
1839 <tr class="layout">
1840 <td class="left"><tt>[4 x i8]</tt></td>
1841 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1842 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1843</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1844<p>Here are some examples of multidimensional arrays:</p>
1845<table class="layout">
1846 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1847 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1848 <td class="left">3x4 array of 32-bit integer values.</td>
1849 </tr>
1850 <tr class="layout">
1851 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1852 <td class="left">12x10 array of single precision floating point values.</td>
1853 </tr>
1854 <tr class="layout">
1855 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1856 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1857 </tr>
1858</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1859
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1860<p>There is no restriction on indexing beyond the end of the array implied by
1861 a static type (though there are restrictions on indexing beyond the bounds
1862 of an allocated object in some cases). This means that single-dimension
1863 'variable sized array' addressing can be implemented in LLVM with a zero
1864 length array type. An implementation of 'pascal style arrays' in LLVM could
1865 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1866
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1867</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1868
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1869<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1870<h4>
1871 <a name="t_function">Function Type</a>
1872</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1873
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1874<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1875
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1876<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1877<p>The function type can be thought of as a function signature. It consists of
1878 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]1879 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1880
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1881<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1882<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1883 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1884</pre>
1885
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1886<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]1887 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1888 which indicates that the function takes a variable number of arguments.
1889 Variable argument functions can access their arguments with
1890 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1891 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1892 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1893
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1894<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1895<table class="layout">
1896 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1897 <td class="left"><tt>i32 (i32)</tt></td>
1898 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1899 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1900 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1901 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1902 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1903 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1904 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1905 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1906 </td>
1907 </tr><tr class="layout">
1908 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1909 <td class="left">A vararg function that takes at least one
1910 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1911 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1912 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1913 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1914 </tr><tr class="layout">
1915 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1916 <td class="left">A function taking an <tt>i32</tt>, returning a
1917 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1918 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1919 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1920</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1921
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1922</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1923
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1924<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1925<h4>
1926 <a name="t_struct">Structure Type</a>
1927</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1928
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1929<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1930
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1931<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1932<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1933 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]1934
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1935<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1936 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1937 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1938 Structures in registers are accessed using the
1939 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1940 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1941
1942<p>Structures may optionally be "packed" structures, which indicate that the
1943 alignment of the struct is one byte, and that there is no padding between
1944 the elements. In non-packed structs, padding between field types is defined
1945 by the target data string to match the underlying processor.</p>
1946
1947<p>Structures can either be "anonymous" or "named". An anonymous structure is
1948 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
1949 are always defined at the top level with a name. Anonmyous types are uniqued
1950 by their contents and can never be recursive since there is no way to write
1951 one. Named types can be recursive.
1952</p>
1953
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1954<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1955<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1956 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
1957 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1958</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1959
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1960<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1961<table class="layout">
1962 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1963 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1964 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1965 </tr>
1966 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1967 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1968 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1969 second element is a <a href="#t_pointer">pointer</a> to a
1970 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1971 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1972 </tr>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1973 <tr class="layout">
1974 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
1975 <td class="left">A packed struct known to be 5 bytes in size.</td>
1976 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1977</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1978
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1979</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1980
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1981<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1982<h4>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1983 <a name="t_opaque">Opaque Type</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1984</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1985
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1986<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1987
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1988<h5>Overview:</h5>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1989<p>Opaque types are used to represent named structure types that do not have a
1990 body specified. This corresponds (for example) to the C notion of a forward
1991 declared structure.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1992
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1993<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1994<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1995 %X = type opaque
1996 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1997</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1998
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1999<h5>Examples:</h5>
2000<table class="layout">
2001 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2002 <td class="left"><tt>opaque</tt></td>
2003 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2004 </tr>
2005</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2006
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2007</div>
2008
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2009
2010
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2011<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2012<h4>
2013 <a name="t_pointer">Pointer Type</a>
2014</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2015
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2016<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2017
2018<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]2019<p>The pointer type is used to specify memory locations.
2020 Pointers are commonly used to reference objects in memory.</p>
2021
2022<p>Pointer types may have an optional address space attribute defining the
2023 numbered address space where the pointed-to object resides. The default
2024 address space is number zero. The semantics of non-zero address
2025 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2026
2027<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2028 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2029
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2030<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2031<pre>
2032 &lt;type&gt; *
2033</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2034
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2035<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2036<table class="layout">
2037 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2038 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2039 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2040 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2041 </tr>
2042 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]2043 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2044 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2045 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2046 <tt>i32</tt>.</td>
2047 </tr>
2048 <tr class="layout">
2049 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2050 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2051 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2052 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2053</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2054
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2055</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2056
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2057<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2058<h4>
2059 <a name="t_vector">Vector Type</a>
2060</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2061
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2062<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2063
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2064<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2065<p>A vector type is a simple derived type that represents a vector of elements.
2066 Vector types are used when multiple primitive data are operated in parallel
2067 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]2068 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2069 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2070
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2071<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2072<pre>
2073 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2074</pre>
2075
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]2076<p>The number of elements is a constant integer value larger than 0; elementtype
2077 may be any integer or floating point type. Vectors of size zero are not
2078 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2079
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2080<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2081<table class="layout">
2082 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2083 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2084 <td class="left">Vector of 4 32-bit integer values.</td>
2085 </tr>
2086 <tr class="layout">
2087 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2088 <td class="left">Vector of 8 32-bit floating-point values.</td>
2089 </tr>
2090 <tr class="layout">
2091 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2092 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2093 </tr>
2094</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2095
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2096</div>
2097
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2098<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2099<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2100<!-- *********************************************************************** -->
2101
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2102<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2103
2104<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2105 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2106
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2107<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2108<h3>
2109 <a name="simpleconstants">Simple Constants</a>
2110</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2111
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2112<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2113
2114<dl>
2115 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2116 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2117 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2118
2119 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2120 <dd>Standard integers (such as '4') are constants of
2121 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2122 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2123
2124 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2125 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2126 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2127 notation (see below). The assembler requires the exact decimal value of a
2128 floating-point constant. For example, the assembler accepts 1.25 but
2129 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2130 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2131
2132 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2133 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2134 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2135</dl>
2136
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2137<p>The one non-intuitive notation for constants is the hexadecimal form of
2138 floating point constants. For example, the form '<tt>double
2139 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2140 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2141 constants are required (and the only time that they are generated by the
2142 disassembler) is when a floating point constant must be emitted but it cannot
2143 be represented as a decimal floating point number in a reasonable number of
2144 digits. For example, NaN's, infinities, and other special values are
2145 represented in their IEEE hexadecimal format so that assembly and disassembly
2146 do not cause any bits to change in the constants.</p>
2147
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2148<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2149 represented using the 16-digit form shown above (which matches the IEEE754
2150 representation for double); float values must, however, be exactly
2151 representable as IEE754 single precision. Hexadecimal format is always used
2152 for long double, and there are three forms of long double. The 80-bit format
2153 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2154 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2155 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2156 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2157 currently supported target uses this format. Long doubles will only work if
2158 they match the long double format on your target. All hexadecimal formats
2159 are big-endian (sign bit at the left).</p>
2160
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2161<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2162</div>
2163
2164<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2165<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2166<a name="aggregateconstants"></a> <!-- old anchor -->
2167<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2168</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2169
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2170<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2171
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2172<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2173 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2174
2175<dl>
2176 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2177 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2178 type definitions (a comma separated list of elements, surrounded by braces
2179 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2180 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2181 Structure constants must have <a href="#t_struct">structure type</a>, and
2182 the number and types of elements must match those specified by the
2183 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2184
2185 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2186 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2187 definitions (a comma separated list of elements, surrounded by square
2188 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2189 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2190 the number and types of elements must match those specified by the
2191 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2192
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2193 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2194 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2195 definitions (a comma separated list of elements, surrounded by
2196 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2197 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2198 have <a href="#t_vector">vector type</a>, and the number and types of
2199 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2200
2201 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2202 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2203 value to zero of <em>any</em> type, including scalar and
2204 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2205 This is often used to avoid having to print large zero initializers
2206 (e.g. for large arrays) and is always exactly equivalent to using explicit
2207 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2208
2209 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2210 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2211 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2212 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2213 be interpreted as part of the instruction stream, metadata is a place to
2214 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2215</dl>
2216
2217</div>
2218
2219<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2220<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2221 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2222</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2223
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2224<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2225
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2226<p>The addresses of <a href="#globalvars">global variables</a>
2227 and <a href="#functionstructure">functions</a> are always implicitly valid
2228 (link-time) constants. These constants are explicitly referenced when
2229 the <a href="#identifiers">identifier for the global</a> is used and always
2230 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2231 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2232
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2233<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2234@X = global i32 17
2235@Y = global i32 42
2236@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2237</pre>
2238
2239</div>
2240
2241<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2242<h3>
2243 <a name="undefvalues">Undefined Values</a>
2244</h3>
2245
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2246<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2247
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2248<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]2249 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2250 Undefined values may be of any type (other than '<tt>label</tt>'
2251 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2252
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2253<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2254 program is well defined no matter what value is used. This gives the
2255 compiler more freedom to optimize. Here are some examples of (potentially
2256 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2257
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2258
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2259<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2260 %A = add %X, undef
2261 %B = sub %X, undef
2262 %C = xor %X, undef
2263Safe:
2264 %A = undef
2265 %B = undef
2266 %C = undef
2267</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2268
2269<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]2270 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]2271
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2272<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2273 %A = or %X, undef
2274 %B = and %X, undef
2275Safe:
2276 %A = -1
2277 %B = 0
2278Unsafe:
2279 %A = undef
2280 %B = undef
2281</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2282
2283<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2284 For example, if <tt>%X</tt> has a zero bit, then the output of the
2285 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2286 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2287 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2288 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2289 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2290 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2291 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2292
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2293<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2294 %A = select undef, %X, %Y
2295 %B = select undef, 42, %Y
2296 %C = select %X, %Y, undef
2297Safe:
2298 %A = %X (or %Y)
2299 %B = 42 (or %Y)
2300 %C = %Y
2301Unsafe:
2302 %A = undef
2303 %B = undef
2304 %C = undef
2305</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2306
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2307<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2308 branch) conditions can go <em>either way</em>, but they have to come from one
2309 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2310 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2311 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2312 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2313 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2314 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2315
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2316<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2317 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2318
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2319 %B = undef
2320 %C = xor %B, %B
2321
2322 %D = undef
2323 %E = icmp lt %D, 4
2324 %F = icmp gte %D, 4
2325
2326Safe:
2327 %A = undef
2328 %B = undef
2329 %C = undef
2330 %D = undef
2331 %E = undef
2332 %F = undef
2333</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2334
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2335<p>This example points out that two '<tt>undef</tt>' operands are not
2336 necessarily the same. This can be surprising to people (and also matches C
2337 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2338 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2339 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2340 its value over its "live range". This is true because the variable doesn't
2341 actually <em>have a live range</em>. Instead, the value is logically read
2342 from arbitrary registers that happen to be around when needed, so the value
2343 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2344 need to have the same semantics or the core LLVM "replace all uses with"
2345 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2346
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2347<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2348 %A = fdiv undef, %X
2349 %B = fdiv %X, undef
2350Safe:
2351 %A = undef
2352b: unreachable
2353</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2354
2355<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2356 value</em> and <em>undefined behavior</em>. An undefined value (like
2357 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2358 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2359 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2360 defined on SNaN's. However, in the second example, we can make a more
2361 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2362 arbitrary value, we are allowed to assume that it could be zero. Since a
2363 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2364 the operation does not execute at all. This allows us to delete the divide and
2365 all code after it. Because the undefined operation "can't happen", the
2366 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2367
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2368<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2369a: store undef -> %X
2370b: store %X -> undef
2371Safe:
2372a: &lt;deleted&gt;
2373b: unreachable
2374</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2375
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2376<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2377 undefined value can be assumed to not have any effect; we can assume that the
2378 value is overwritten with bits that happen to match what was already there.
2379 However, a store <em>to</em> an undefined location could clobber arbitrary
2380 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2381
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2382</div>
2383
2384<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2385<h3>
2386 <a name="trapvalues">Trap Values</a>
2387</h3>
2388
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2389<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2390
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2391<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2392 instead of representing an unspecified bit pattern, they represent the
2393 fact that an instruction or constant expression which cannot evoke side
2394 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2395 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2396
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2397<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]2398 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2399 <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]2400
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2401<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2402
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2403<ul>
2404<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2405 their operands.</li>
2406
2407<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2408 to their dynamic predecessor basic block.</li>
2409
2410<li>Function arguments depend on the corresponding actual argument values in
2411 the dynamic callers of their functions.</li>
2412
2413<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2414 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2415 control back to them.</li>
2416
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2417<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2418 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2419 or exception-throwing call instructions that dynamically transfer control
2420 back to them.</li>
2421
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2422<li>Non-volatile loads and stores depend on the most recent stores to all of the
2423 referenced memory addresses, following the order in the IR
2424 (including loads and stores implied by intrinsics such as
2425 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2426
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2427<!-- TODO: In the case of multiple threads, this only applies if the store
2428 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2429
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2430<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2431
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2432<li>An instruction with externally visible side effects depends on the most
2433 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2434 the order in the IR. (This includes
2435 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2436
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2437<li>An instruction <i>control-depends</i> on a
2438 <a href="#terminators">terminator instruction</a>
2439 if the terminator instruction has multiple successors and the instruction
2440 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2441 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2442
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2443<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2444 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2445 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2446 successor.</li>
2447
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2448<li>Dependence is transitive.</li>
2449
2450</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2451
2452<p>Whenever a trap value is generated, all values which depend on it evaluate
2453 to trap. If they have side effects, the evoke their side effects as if each
2454 operand with a trap value were undef. If they have externally-visible side
2455 effects, the behavior is undefined.</p>
2456
2457<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2458
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2459<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2460entry:
2461 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2462 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2463 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2464 store i32 0, i32* %trap_yet_again ; undefined behavior
2465
2466 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2467 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2468
2469 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2470
2471 %narrowaddr = bitcast i32* @g to i16*
2472 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2473 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2474 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2475
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2476 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2477 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2478
2479true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2480 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2481 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2482 br label %end
2483
2484end:
2485 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2486 ; Both edges into this PHI are
2487 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2488 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2489
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2490 volatile store i32 0, i32* @g ; This would depend on the store in %true
2491 ; if %cmp is true, or the store in %entry
2492 ; otherwise, so this is undefined behavior.
2493
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2494 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2495 ; The same branch again, but this time the
2496 ; true block doesn't have side effects.
2497
2498second_true:
2499 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2500 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2501
2502second_end:
2503 volatile store i32 0, i32* @g ; This time, the instruction always depends
2504 ; on the store in %end. Also, it is
2505 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2506 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2507 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2508</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2509
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2510</div>
2511
2512<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2513<h3>
2514 <a name="blockaddress">Addresses of Basic Blocks</a>
2515</h3>
2516
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2517<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2518
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2519<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2520
2521<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2522 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2523 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2524
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2525<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2526 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2527 comparisons against null. Pointer equality tests between labels addresses
2528 results in undefined behavior &mdash; though, again, comparison against null
2529 is ok, and no label is equal to the null pointer. This may be passed around
2530 as an opaque pointer sized value as long as the bits are not inspected. This
2531 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2532 long as the original value is reconstituted before the <tt>indirectbr</tt>
2533 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2534
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2535<p>Finally, some targets may provide defined semantics when using the value as
2536 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2537
2538</div>
2539
2540
2541<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2542<h3>
2543 <a name="constantexprs">Constant Expressions</a>
2544</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2545
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2546<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2547
2548<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2549 to be used as constants. Constant expressions may be of
2550 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2551 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2552 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2553
2554<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2555 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2556 <dd>Truncate a constant to another type. The bit size of CST must be larger
2557 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2558
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2559 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2560 <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]2561 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2562
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2563 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2564 <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]2565 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2566
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2567 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2568 <dd>Truncate a floating point constant to another floating point type. The
2569 size of CST must be larger than the size of TYPE. Both types must be
2570 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2571
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2572 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2573 <dd>Floating point extend a constant to another type. The size of CST must be
2574 smaller or equal to the size of TYPE. Both types must be floating
2575 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2576
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2577 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2578 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2579 constant. TYPE must be a scalar or vector integer type. CST must be of
2580 scalar or vector floating point type. Both CST and TYPE must be scalars,
2581 or vectors of the same number of elements. If the value won't fit in the
2582 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2583
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2584 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2585 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2586 constant. TYPE must be a scalar or vector integer type. CST must be of
2587 scalar or vector floating point type. Both CST and TYPE must be scalars,
2588 or vectors of the same number of elements. If the value won't fit in the
2589 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2590
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2591 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2592 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2593 constant. TYPE must be a scalar or vector floating point type. CST must be
2594 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2595 vectors of the same number of elements. If the value won't fit in the
2596 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2597
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2598 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2599 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2600 constant. TYPE must be a scalar or vector floating point type. CST must be
2601 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2602 vectors of the same number of elements. If the value won't fit in the
2603 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2604
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2605 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2606 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2607 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2608 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2609 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2610
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2611 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2612 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2613 type. CST must be of integer type. The CST value is zero extended,
2614 truncated, or unchanged to make it fit in a pointer size. This one is
2615 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2616
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2617 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2618 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2619 are the same as those for the <a href="#i_bitcast">bitcast
2620 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2621
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2622 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2623 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2624 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2625 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2626 instruction, the index list may have zero or more indexes, which are
2627 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2628
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2629 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2630 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2631
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2632 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2633 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2634
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2635 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2636 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2637
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2638 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2639 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2640 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2641
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2642 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2643 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2644 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2645
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2646 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2647 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2648 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2649
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2650 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2651 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2652 constants. The index list is interpreted in a similar manner as indices in
2653 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2654 index value must be specified.</dd>
2655
2656 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2657 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2658 constants. The index list is interpreted in a similar manner as indices in
2659 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2660 index value must be specified.</dd>
2661
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2662 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2663 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2664 be any of the <a href="#binaryops">binary</a>
2665 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2666 on operands are the same as those for the corresponding instruction
2667 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2668</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2669
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2670</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2671
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2672</div>
2673
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2674<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2675<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2676<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2677<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2678<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2679<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2680<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2681</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2682
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2683<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2684
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2685<p>LLVM supports inline assembler expressions (as opposed
2686 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2687 a special value. This value represents the inline assembler as a string
2688 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2689 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2690 expression has side effects, and a flag indicating whether the function
2691 containing the asm needs to align its stack conservatively. An example
2692 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2693
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2694<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2695i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2696</pre>
2697
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2698<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2699 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2700 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2701
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2702<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2703%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]2704</pre>
2705
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2706<p>Inline asms with side effects not visible in the constraint list must be
2707 marked as having side effects. This is done through the use of the
2708 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2709
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2710<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2711call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2712</pre>
2713
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2714<p>In some cases inline asms will contain code that will not work unless the
2715 stack is aligned in some way, such as calls or SSE instructions on x86,
2716 yet will not contain code that does that alignment within the asm.
2717 The compiler should make conservative assumptions about what the asm might
2718 contain and should generate its usual stack alignment code in the prologue
2719 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2720
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2721<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2722call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2723</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2724
2725<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2726 first.</p>
2727
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2728<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2729 documented here. Constraints on what can be done (e.g. duplication, moving,
2730 etc need to be documented). This is probably best done by reference to
2731 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2732
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2733<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2734<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2735</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2736
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2737<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2738
2739<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2740 attached to it that contains a list of constant integers. If present, the
2741 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2742 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2743 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2744 source code that produced it. For example:</p>
2745
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2746<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2747call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2748...
2749!42 = !{ i32 1234567 }
2750</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2751
2752<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]2753 IR. If the MDNode contains multiple constants, the code generator will use
2754 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]2755
2756</div>
2757
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2758</div>
2759
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2760<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2761<h3>
2762 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2763</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2764
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2765<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2766
2767<p>LLVM IR allows metadata to be attached to instructions in the program that
2768 can convey extra information about the code to the optimizers and code
2769 generator. One example application of metadata is source-level debug
2770 information. There are two metadata primitives: strings and nodes. All
2771 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2772 preceding exclamation point ('<tt>!</tt>').</p>
2773
2774<p>A metadata string is a string surrounded by double quotes. It can contain
2775 any character by escaping non-printable characters with "\xx" where "xx" is
2776 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2777
2778<p>Metadata nodes are represented with notation similar to structure constants
2779 (a comma separated list of elements, surrounded by braces and preceded by an
2780 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2781 10}</tt>". Metadata nodes can have any values as their operand.</p>
2782
2783<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2784 metadata nodes, which can be looked up in the module symbol table. For
2785 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2786
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2787<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2788 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2789
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2790<div class="doc_code">
2791<pre>
2792call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2793</pre>
2794</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2795
2796<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2797 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2798
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2799<div class="doc_code">
2800<pre>
2801%indvar.next = add i64 %indvar, 1, !dbg !21
2802</pre>
2803</div>
2804
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2805</div>
2806
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2807</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2808
2809<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2810<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2811 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2812</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2813<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2814<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2815<p>LLVM has a number of "magic" global variables that contain data that affect
2816code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2817of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2818section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2819by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2820
2821<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2822<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2823<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2824</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2825
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2826<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2827
2828<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2829href="#linkage_appending">appending linkage</a>. This array contains a list of
2830pointers to global variables and functions which may optionally have a pointer
2831cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2832
2833<pre>
2834 @X = global i8 4
2835 @Y = global i32 123
2836
2837 @llvm.used = appending global [2 x i8*] [
2838 i8* @X,
2839 i8* bitcast (i32* @Y to i8*)
2840 ], section "llvm.metadata"
2841</pre>
2842
2843<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2844compiler, assembler, and linker are required to treat the symbol as if there is
2845a reference to the global that it cannot see. For example, if a variable has
2846internal linkage and no references other than that from the <tt>@llvm.used</tt>
2847list, it cannot be deleted. This is commonly used to represent references from
2848inline asms and other things the compiler cannot "see", and corresponds to
2849"attribute((used))" in GNU C.</p>
2850
2851<p>On some targets, the code generator must emit a directive to the assembler or
2852object file to prevent the assembler and linker from molesting the symbol.</p>
2853
2854</div>
2855
2856<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2857<h3>
2858 <a name="intg_compiler_used">
2859 The '<tt>llvm.compiler.used</tt>' Global Variable
2860 </a>
2861</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2862
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2863<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2864
2865<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2866<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2867touching the symbol. On targets that support it, this allows an intelligent
2868linker to optimize references to the symbol without being impeded as it would be
2869by <tt>@llvm.used</tt>.</p>
2870
2871<p>This is a rare construct that should only be used in rare circumstances, and
2872should not be exposed to source languages.</p>
2873
2874</div>
2875
2876<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2877<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2878<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2879</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2880
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2881<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2882<pre>
2883%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2884@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2885</pre>
2886<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.
2887</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2888
2889</div>
2890
2891<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2892<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2893<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2894</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2895
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2896<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2897<pre>
2898%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2899@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2900</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2901
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2902<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.
2903</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2904
2905</div>
2906
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2907</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2908
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2909<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2910<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2911<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2912
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2913<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2914
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2915<p>The LLVM instruction set consists of several different classifications of
2916 instructions: <a href="#terminators">terminator
2917 instructions</a>, <a href="#binaryops">binary instructions</a>,
2918 <a href="#bitwiseops">bitwise binary instructions</a>,
2919 <a href="#memoryops">memory instructions</a>, and
2920 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2921
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2922<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2923<h3>
2924 <a name="terminators">Terminator Instructions</a>
2925</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2926
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2927<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2928
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2929<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2930 in a program ends with a "Terminator" instruction, which indicates which
2931 block should be executed after the current block is finished. These
2932 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2933 control flow, not values (the one exception being the
2934 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2935
Duncan Sands626b0242010-04-15 20:35:54 +0000[diff] [blame]2936<p>There are seven different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2937 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2938 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2939 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2940 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2941 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2942 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2943 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2944
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2945<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2946<h4>
2947 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2948</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2949
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2950<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2951
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2952<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2953<pre>
2954 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]2955 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2956</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2957
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2958<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2959<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2960 a value) from a function back to the caller.</p>
2961
2962<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2963 value and then causes control flow, and one that just causes control flow to
2964 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2965
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2966<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2967<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2968 return value. The type of the return value must be a
2969 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2970
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2971<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2972 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2973 value or a return value with a type that does not match its type, or if it
2974 has a void return type and contains a '<tt>ret</tt>' instruction with a
2975 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2976
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2977<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2978<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2979 the calling function's context. If the caller is a
2980 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2981 instruction after the call. If the caller was an
2982 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2983 the beginning of the "normal" destination block. If the instruction returns
2984 a value, that value shall set the call or invoke instruction's return
2985 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2986
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2987<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2988<pre>
2989 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2990 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2991 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]2992</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2993
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2994</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2995<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2996<h4>
2997 <a name="i_br">'<tt>br</tt>' Instruction</a>
2998</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2999
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3000<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3001
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3002<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3003<pre>
3004 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3005</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3006
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3007<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3008<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3009 different basic block in the current function. There are two forms of this
3010 instruction, corresponding to a conditional branch and an unconditional
3011 branch.</p>
3012
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3013<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3014<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3015 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3016 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3017 target.</p>
3018
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3019<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3020<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3021 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3022 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3023 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3024
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3025<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3026<pre>
3027Test:
3028 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3029 br i1 %cond, label %IfEqual, label %IfUnequal
3030IfEqual:
3031 <a href="#i_ret">ret</a> i32 1
3032IfUnequal:
3033 <a href="#i_ret">ret</a> i32 0
3034</pre>
3035
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3036</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3037
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3038<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3039<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3040 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3041</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3042
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3043<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3044
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3045<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3046<pre>
3047 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3048</pre>
3049
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3050<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3051<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]3052 several different places. It is a generalization of the '<tt>br</tt>'
3053 instruction, allowing a branch to occur to one of many possible
3054 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3055
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3056<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3057<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3058 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3059 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3060 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3061
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3062<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3063<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3064 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3065 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3066 transferred to the corresponding destination; otherwise, control flow is
3067 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3068
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3069<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3070<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3071 <tt>switch</tt> instruction, this instruction may be code generated in
3072 different ways. For example, it could be generated as a series of chained
3073 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3074
3075<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3076<pre>
3077 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3078 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3079 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3080
3081 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3082 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3083
3084 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3085 switch i32 %val, label %otherwise [ i32 0, label %onzero
3086 i32 1, label %onone
3087 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3088</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3089
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3090</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3091
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3092
3093<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3094<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3095 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3096</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3097
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3098<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3099
3100<h5>Syntax:</h5>
3101<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3102 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]3103</pre>
3104
3105<h5>Overview:</h5>
3106
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3107<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3108 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3109 "<tt>address</tt>". Address must be derived from a <a
3110 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3111
3112<h5>Arguments:</h5>
3113
3114<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3115 rest of the arguments indicate the full set of possible destinations that the
3116 address may point to. Blocks are allowed to occur multiple times in the
3117 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3118
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3119<p>This destination list is required so that dataflow analysis has an accurate
3120 understanding of the CFG.</p>
3121
3122<h5>Semantics:</h5>
3123
3124<p>Control transfers to the block specified in the address argument. All
3125 possible destination blocks must be listed in the label list, otherwise this
3126 instruction has undefined behavior. This implies that jumps to labels
3127 defined in other functions have undefined behavior as well.</p>
3128
3129<h5>Implementation:</h5>
3130
3131<p>This is typically implemented with a jump through a register.</p>
3132
3133<h5>Example:</h5>
3134<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3135 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3136</pre>
3137
3138</div>
3139
3140
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3141<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3142<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3143 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3144</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3145
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3146<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3147
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3148<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3149<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3150 &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]3151 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3152</pre>
3153
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3154<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3155<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3156 function, with the possibility of control flow transfer to either the
3157 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3158 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3159 control flow will return to the "normal" label. If the callee (or any
3160 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3161 instruction, control is interrupted and continued at the dynamically nearest
3162 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3163
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3164<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3165<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3166
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3167<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3168 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3169 convention</a> the call should use. If none is specified, the call
3170 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3171
3172 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3173 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3174 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3175
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3176 <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]3177 function value being invoked. In most cases, this is a direct function
3178 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3179 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3180
3181 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3182 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3183
3184 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3185 signature argument types and parameter attributes. All arguments must be
3186 of <a href="#t_firstclass">first class</a> type. If the function
3187 signature indicates the function accepts a variable number of arguments,
3188 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3189
3190 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3191 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3192
3193 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3194 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3195
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3196 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3197 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3198 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3199</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3200
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3201<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3202<p>This instruction is designed to operate as a standard
3203 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3204 primary difference is that it establishes an association with a label, which
3205 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3206
3207<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3208 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3209 exception. Additionally, this is important for implementation of
3210 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3211
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3212<p>For the purposes of the SSA form, the definition of the value returned by the
3213 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3214 block to the "normal" label. If the callee unwinds then no return value is
3215 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3216
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3217<p>Note that the code generator does not yet completely support unwind, and
3218that the invoke/unwind semantics are likely to change in future versions.</p>
3219
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3220<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3221<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3222 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3223 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3224 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3225 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3226</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3227
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3228</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3229
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3230<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3231
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3232<h4>
3233 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3234</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3235
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3236<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3237
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3238<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3239<pre>
3240 unwind
3241</pre>
3242
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3243<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3244<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3245 at the first callee in the dynamic call stack which used
3246 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3247 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3248
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3249<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3250<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3251 immediately halt. The dynamic call stack is then searched for the
3252 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3253 Once found, execution continues at the "exceptional" destination block
3254 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3255 instruction in the dynamic call chain, undefined behavior results.</p>
3256
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3257<p>Note that the code generator does not yet completely support unwind, and
3258that the invoke/unwind semantics are likely to change in future versions.</p>
3259
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3260</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3261
3262<!-- _______________________________________________________________________ -->
3263
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3264<h4>
3265 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3266</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3267
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3268<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3269
3270<h5>Syntax:</h5>
3271<pre>
3272 unreachable
3273</pre>
3274
3275<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3276<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3277 instruction is used to inform the optimizer that a particular portion of the
3278 code is not reachable. This can be used to indicate that the code after a
3279 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3280
3281<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3282<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3283
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3284</div>
3285
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3286</div>
3287
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3288<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3289<h3>
3290 <a name="binaryops">Binary Operations</a>
3291</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3292
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3293<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3294
3295<p>Binary operators are used to do most of the computation in a program. They
3296 require two operands of the same type, execute an operation on them, and
3297 produce a single value. The operands might represent multiple data, as is
3298 the case with the <a href="#t_vector">vector</a> data type. The result value
3299 has the same type as its operands.</p>
3300
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3301<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3302
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3303<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3304<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3305 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3306</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3307
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3308<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3309
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3310<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3311<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3312 &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]3313 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3314 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3315 &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]3316</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3317
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3318<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3319<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3320
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3321<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3322<p>The two arguments to the '<tt>add</tt>' instruction must
3323 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3324 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3325
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3326<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3327<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3328
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3329<p>If the sum has unsigned overflow, the result returned is the mathematical
3330 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]3331
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3332<p>Because LLVM integers use a two's complement representation, this instruction
3333 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3334
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3335<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3336 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3337 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3338 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3339 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3340
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3341<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3342<pre>
3343 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3344</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3345
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3346</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3347
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3348<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3349<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3350 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3351</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3352
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3353<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3354
3355<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3356<pre>
3357 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3358</pre>
3359
3360<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3361<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3362
3363<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3364<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3365 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3366 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3367
3368<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3369<p>The value produced is the floating point sum of the two operands.</p>
3370
3371<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3372<pre>
3373 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3374</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3375
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3376</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3377
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3378<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3379<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3380 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3381</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3382
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3383<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3384
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3385<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3386<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3387 &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]3388 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3389 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3390 &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]3391</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3392
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3393<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3394<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3395 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3396
3397<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3398 '<tt>neg</tt>' instruction present in most other intermediate
3399 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3400
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3401<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3402<p>The two arguments to the '<tt>sub</tt>' instruction must
3403 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3404 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3405
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3406<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3407<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3408
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3409<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3410 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3411 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3412
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3413<p>Because LLVM integers use a two's complement representation, this instruction
3414 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3415
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3416<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3417 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3418 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3419 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3420 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3421
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3422<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3423<pre>
3424 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3425 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3426</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3427
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3428</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3429
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3430<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3431<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3432 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3433</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3434
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3435<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3436
3437<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3438<pre>
3439 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3440</pre>
3441
3442<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3443<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3444 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3445
3446<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3447 '<tt>fneg</tt>' instruction present in most other intermediate
3448 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3449
3450<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3451<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3452 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3453 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3454
3455<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3456<p>The value produced is the floating point difference of the two operands.</p>
3457
3458<h5>Example:</h5>
3459<pre>
3460 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3461 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3462</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3463
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3464</div>
3465
3466<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3467<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3468 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3469</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3470
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3471<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3472
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3473<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3474<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3475 &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]3476 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3477 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3478 &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]3479</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3480
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3481<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3482<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3483
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3484<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3485<p>The two arguments to the '<tt>mul</tt>' instruction must
3486 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3487 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3488
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3489<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3490<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3491
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3492<p>If the result of the multiplication has unsigned overflow, the result
3493 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3494 width of the result.</p>
3495
3496<p>Because LLVM integers use a two's complement representation, and the result
3497 is the same width as the operands, this instruction returns the correct
3498 result for both signed and unsigned integers. If a full product
3499 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3500 be sign-extended or zero-extended as appropriate to the width of the full
3501 product.</p>
3502
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3503<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3504 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3505 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3506 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3507 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3508
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3509<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3510<pre>
3511 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3512</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3513
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3514</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3515
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3516<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3517<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3518 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3519</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3520
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3521<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3522
3523<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3524<pre>
3525 &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]3526</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3527
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3528<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3529<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3530
3531<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3532<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3533 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3534 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3535
3536<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3537<p>The value produced is the floating point product of the two operands.</p>
3538
3539<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3540<pre>
3541 &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]3542</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3543
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3544</div>
3545
3546<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3547<h4>
3548 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3549</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3550
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3551<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3552
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3553<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3554<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3555 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3556 &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]3557</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3558
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3559<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3560<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3561
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3562<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3563<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3564 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3565 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3566
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3567<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3568<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3569
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3570<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3571 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3572
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3573<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3574
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3575<p>If the <tt>exact</tt> keyword is present, the result value of the
3576 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3577 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3578
3579
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3580<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3581<pre>
3582 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3583</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3584
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3585</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3586
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3587<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3588<h4>
3589 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3590</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3591
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3592<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3593
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3594<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3595<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3596 &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]3597 &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]3598</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3599
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3600<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3601<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3602
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3603<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3604<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3605 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3606 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3607
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3608<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3609<p>The value produced is the signed integer quotient of the two operands rounded
3610 towards zero.</p>
3611
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3612<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3613 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3614
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3615<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3616 undefined behavior; this is a rare case, but can occur, for example, by doing
3617 a 32-bit division of -2147483648 by -1.</p>
3618
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3619<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3620 <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]3621 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3622
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3623<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3624<pre>
3625 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3626</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3627
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3628</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3629
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3630<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3631<h4>
3632 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3633</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3634
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3635<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3636
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3637<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3638<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3639 &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]3640</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3641
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3642<h5>Overview:</h5>
3643<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3644
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3645<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3646<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3647 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3648 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3649
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3650<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3651<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3652
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3653<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3654<pre>
3655 &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]3656</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3657
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3658</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3659
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3660<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3661<h4>
3662 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3663</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3664
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3665<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3666
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3667<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3668<pre>
3669 &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]3670</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3671
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3672<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3673<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3674 division of its two arguments.</p>
3675
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3676<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3677<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3678 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3679 values. Both arguments must have identical types.</p>
3680
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3681<h5>Semantics:</h5>
3682<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3683 This instruction always performs an unsigned division to get the
3684 remainder.</p>
3685
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3686<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3687 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3688
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3689<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3690
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3691<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3692<pre>
3693 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3694</pre>
3695
3696</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3697
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3698<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3699<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3700 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3701</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3702
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3703<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3704
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3705<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3706<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3707 &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]3708</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3709
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3710<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3711<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3712 division of its two operands. This instruction can also take
3713 <a href="#t_vector">vector</a> versions of the values in which case the
3714 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3715
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3716<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3717<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3718 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3719 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3720
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3721<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3722<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3723 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3724 <i>modulo</i> operator (where the result is either zero or has the same sign
3725 as the divisor, <tt>op2</tt>) of a value.
3726 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3727 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3728 Math Forum</a>. For a table of how this is implemented in various languages,
3729 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3730 Wikipedia: modulo operation</a>.</p>
3731
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3732<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3733 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3734
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3735<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3736 Overflow also leads to undefined behavior; this is a rare case, but can
3737 occur, for example, by taking the remainder of a 32-bit division of
3738 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3739 lets srem be implemented using instructions that return both the result of
3740 the division and the remainder.)</p>
3741
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3742<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3743<pre>
3744 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3745</pre>
3746
3747</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3748
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3749<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3750<h4>
3751 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3752</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3753
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3754<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3755
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3756<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3757<pre>
3758 &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]3759</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3760
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3761<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3762<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3763 its two operands.</p>
3764
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3765<h5>Arguments:</h5>
3766<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3767 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3768 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3769
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3770<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3771<p>This instruction returns the <i>remainder</i> of a division. The remainder
3772 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3773
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3774<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3775<pre>
3776 &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]3777</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3778
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3779</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3780
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3781</div>
3782
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3783<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3784<h3>
3785 <a name="bitwiseops">Bitwise Binary Operations</a>
3786</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3787
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3788<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3789
3790<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3791 program. They are generally very efficient instructions and can commonly be
3792 strength reduced from other instructions. They require two operands of the
3793 same type, execute an operation on them, and produce a single value. The
3794 resulting value is the same type as its operands.</p>
3795
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3796<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3797<h4>
3798 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3799</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3800
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3801<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3802
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3803<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3804<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3805 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3806 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3807 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3808 &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]3809</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3810
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3811<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3812<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3813 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3814
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3815<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3816<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3817 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3818 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3819
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3820<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3821<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3822 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3823 is (statically or dynamically) negative or equal to or larger than the number
3824 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3825 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3826 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3827
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3828<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3829 <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]3830 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3831 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3832 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3833 they would if the shift were expressed as a mul instruction with the same
3834 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3835
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3836<h5>Example:</h5>
3837<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3838 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3839 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3840 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3841 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3842 &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]3843</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3844
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3845</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3846
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3847<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3848<h4>
3849 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3850</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3851
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3852<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3853
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3854<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3855<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3856 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3857 &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]3858</pre>
3859
3860<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3861<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3862 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3863
3864<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3865<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3866 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3867 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3868
3869<h5>Semantics:</h5>
3870<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3871 significant bits of the result will be filled with zero bits after the shift.
3872 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3873 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3874 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3875 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3876
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3877<p>If the <tt>exact</tt> keyword is present, the result value of the
3878 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3879 shifted out are non-zero.</p>
3880
3881
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3882<h5>Example:</h5>
3883<pre>
3884 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3885 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3886 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3887 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3888 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3889 &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]3890</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3891
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3892</div>
3893
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3894<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3895<h4>
3896 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3897</h4>
3898
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3899<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3900
3901<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3902<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3903 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3904 &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]3905</pre>
3906
3907<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3908<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3909 operand shifted to the right a specified number of bits with sign
3910 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3911
3912<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3913<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3914 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3915 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3916
3917<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3918<p>This instruction always performs an arithmetic shift right operation, The
3919 most significant bits of the result will be filled with the sign bit
3920 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3921 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3922 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3923 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3924
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3925<p>If the <tt>exact</tt> keyword is present, the result value of the
3926 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3927 shifted out are non-zero.</p>
3928
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3929<h5>Example:</h5>
3930<pre>
3931 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3932 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3933 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3934 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3935 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3936 &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]3937</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3938
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3939</div>
3940
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3941<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3942<h4>
3943 <a name="i_and">'<tt>and</tt>' Instruction</a>
3944</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3945
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3946<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3947
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3948<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3949<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3950 &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]3951</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3952
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3953<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3954<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3955 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3956
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3957<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3958<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3959 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3960 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3961
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3962<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3963<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3964
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3965<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3966 <tbody>
3967 <tr>
3968 <td>In0</td>
3969 <td>In1</td>
3970 <td>Out</td>
3971 </tr>
3972 <tr>
3973 <td>0</td>
3974 <td>0</td>
3975 <td>0</td>
3976 </tr>
3977 <tr>
3978 <td>0</td>
3979 <td>1</td>
3980 <td>0</td>
3981 </tr>
3982 <tr>
3983 <td>1</td>
3984 <td>0</td>
3985 <td>0</td>
3986 </tr>
3987 <tr>
3988 <td>1</td>
3989 <td>1</td>
3990 <td>1</td>
3991 </tr>
3992 </tbody>
3993</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3994
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3995<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3996<pre>
3997 &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]3998 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3999 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4000</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4001</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4002<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4003<h4>
4004 <a name="i_or">'<tt>or</tt>' Instruction</a>
4005</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4006
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4007<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4008
4009<h5>Syntax:</h5>
4010<pre>
4011 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4012</pre>
4013
4014<h5>Overview:</h5>
4015<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4016 two operands.</p>
4017
4018<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4019<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4020 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4021 values. Both arguments must have identical types.</p>
4022
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4023<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4024<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4025
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4026<table border="1" cellspacing="0" cellpadding="4">
4027 <tbody>
4028 <tr>
4029 <td>In0</td>
4030 <td>In1</td>
4031 <td>Out</td>
4032 </tr>
4033 <tr>
4034 <td>0</td>
4035 <td>0</td>
4036 <td>0</td>
4037 </tr>
4038 <tr>
4039 <td>0</td>
4040 <td>1</td>
4041 <td>1</td>
4042 </tr>
4043 <tr>
4044 <td>1</td>
4045 <td>0</td>
4046 <td>1</td>
4047 </tr>
4048 <tr>
4049 <td>1</td>
4050 <td>1</td>
4051 <td>1</td>
4052 </tr>
4053 </tbody>
4054</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4055
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4056<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4057<pre>
4058 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4059 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4060 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4061</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4062
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4063</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4064
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4065<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4066<h4>
4067 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4068</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4069
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4070<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4071
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4072<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4073<pre>
4074 &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]4075</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4076
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4077<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4078<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4079 its two operands. The <tt>xor</tt> is used to implement the "one's
4080 complement" operation, which is the "~" operator in C.</p>
4081
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4082<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4083<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4084 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4085 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4086
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4087<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4088<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4089
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4090<table border="1" cellspacing="0" cellpadding="4">
4091 <tbody>
4092 <tr>
4093 <td>In0</td>
4094 <td>In1</td>
4095 <td>Out</td>
4096 </tr>
4097 <tr>
4098 <td>0</td>
4099 <td>0</td>
4100 <td>0</td>
4101 </tr>
4102 <tr>
4103 <td>0</td>
4104 <td>1</td>
4105 <td>1</td>
4106 </tr>
4107 <tr>
4108 <td>1</td>
4109 <td>0</td>
4110 <td>1</td>
4111 </tr>
4112 <tr>
4113 <td>1</td>
4114 <td>1</td>
4115 <td>0</td>
4116 </tr>
4117 </tbody>
4118</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4119
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4120<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4121<pre>
4122 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4123 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4124 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4125 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4126</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4127
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4128</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4129
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4130</div>
4131
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4132<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4133<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4134 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4135</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4136
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4137<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4138
4139<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4140 target-independent manner. These instructions cover the element-access and
4141 vector-specific operations needed to process vectors effectively. While LLVM
4142 does directly support these vector operations, many sophisticated algorithms
4143 will want to use target-specific intrinsics to take full advantage of a
4144 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4145
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4146<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4147<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4148 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4149</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4150
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4151<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4152
4153<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4154<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4155 &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]4156</pre>
4157
4158<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4159<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4160 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4161
4162
4163<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4164<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4165 of <a href="#t_vector">vector</a> type. The second operand is an index
4166 indicating the position from which to extract the element. The index may be
4167 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4168
4169<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4170<p>The result is a scalar of the same type as the element type of
4171 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4172 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4173 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4174
4175<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4176<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4177 &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]4178</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4179
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4180</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4181
4182<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4183<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4184 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4185</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4186
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4187<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4188
4189<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4190<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4191 &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]4192</pre>
4193
4194<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4195<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4196 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4197
4198<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4199<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4200 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4201 whose type must equal the element type of the first operand. The third
4202 operand is an index indicating the position at which to insert the value.
4203 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4204
4205<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4206<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4207 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4208 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4209 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4210
4211<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4212<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4213 &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]4214</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4215
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4216</div>
4217
4218<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4219<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4220 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4221</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4222
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4223<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4224
4225<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4226<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4227 &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]4228</pre>
4229
4230<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4231<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4232 from two input vectors, returning a vector with the same element type as the
4233 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4234
4235<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4236<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4237 with types that match each other. The third argument is a shuffle mask whose
4238 element type is always 'i32'. The result of the instruction is a vector
4239 whose length is the same as the shuffle mask and whose element type is the
4240 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4241
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4242<p>The shuffle mask operand is required to be a constant vector with either
4243 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4244
4245<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4246<p>The elements of the two input vectors are numbered from left to right across
4247 both of the vectors. The shuffle mask operand specifies, for each element of
4248 the result vector, which element of the two input vectors the result element
4249 gets. The element selector may be undef (meaning "don't care") and the
4250 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4251
4252<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4253<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4254 &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]4255 &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]4256 &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]4257 &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]4258 &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]4259 &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]4260 &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]4261 &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]4262</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4263
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4264</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4265
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4266</div>
4267
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4268<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4269<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4270 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4271</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4272
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4273<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4274
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4275<p>LLVM supports several instructions for working with
4276 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4277
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4278<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4279<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4280 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4281</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4282
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4283<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4284
4285<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4286<pre>
4287 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4288</pre>
4289
4290<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4291<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4292 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4293
4294<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4295<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4296 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4297 <a href="#t_array">array</a> type. The operands are constant indices to
4298 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4299 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4300 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4301 <ul>
4302 <li>Since the value being indexed is not a pointer, the first index is
4303 omitted and assumed to be zero.</li>
4304 <li>At least one index must be specified.</li>
4305 <li>Not only struct indices but also array indices must be in
4306 bounds.</li>
4307 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4308
4309<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4310<p>The result is the value at the position in the aggregate specified by the
4311 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4312
4313<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4314<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4315 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4316</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4317
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4318</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4319
4320<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4321<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4322 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4323</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4324
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4325<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4326
4327<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4328<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4329 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4330</pre>
4331
4332<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4333<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4334 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4335
4336<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4337<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4338 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4339 <a href="#t_array">array</a> type. The second operand is a first-class
4340 value to insert. The following operands are constant indices indicating
4341 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]4342 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4343 value to insert must have the same type as the value identified by the
4344 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4345
4346<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4347<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4348 that of <tt>val</tt> except that the value at the position specified by the
4349 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4350
4351<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4352<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4353 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4354 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4355 %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]4356</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4357
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4358</div>
4359
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4360</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4361
4362<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4363<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4364 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4365</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4366
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4367<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4368
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4369<p>A key design point of an SSA-based representation is how it represents
4370 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4371 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4372 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4373
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4374<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4375<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4376 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4377</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4378
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4379<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4380
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4381<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4382<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4383 &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]4384</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4385
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4386<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4387<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4388 currently executing function, to be automatically released when this function
4389 returns to its caller. The object is always allocated in the generic address
4390 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4391
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4392<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4393<p>The '<tt>alloca</tt>' instruction
4394 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4395 runtime stack, returning a pointer of the appropriate type to the program.
4396 If "NumElements" is specified, it is the number of elements allocated,
4397 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4398 specified, the value result of the allocation is guaranteed to be aligned to
4399 at least that boundary. If not specified, or if zero, the target can choose
4400 to align the allocation on any convenient boundary compatible with the
4401 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4402
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4403<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4404
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4405<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4406<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4407 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4408 memory is automatically released when the function returns. The
4409 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4410 variables that must have an address available. When the function returns
4411 (either with the <tt><a href="#i_ret">ret</a></tt>
4412 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4413 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4414
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4415<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4416<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4417 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4418 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4419 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4420 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4421</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4422
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4423</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4424
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4425<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4426<h4>
4427 <a name="i_load">'<tt>load</tt>' Instruction</a>
4428</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4429
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4430<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4431
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4432<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4433<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4434 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4435 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4436 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4437</pre>
4438
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4439<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4440<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4441
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4442<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4443<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4444 from which to load. The pointer must point to
4445 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4446 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4447 number or order of execution of this <tt>load</tt> with other <a
4448 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4449
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4450<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4451 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]4452 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4453 alignment for the target. It is the responsibility of the code emitter to
4454 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4455 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4456 produce less efficient code. An alignment of 1 is always safe.</p>
4457
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4458<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4459 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4460 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4461 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4462 and code generator that this load is not expected to be reused in the cache.
4463 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4464 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4465
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4466<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4467<p>The location of memory pointed to is loaded. If the value being loaded is of
4468 scalar type then the number of bytes read does not exceed the minimum number
4469 of bytes needed to hold all bits of the type. For example, loading an
4470 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4471 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4472 is undefined if the value was not originally written using a store of the
4473 same type.</p>
4474
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4475<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4476<pre>
4477 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4478 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4479 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4480</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4481
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4482</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4483
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4484<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4485<h4>
4486 <a name="i_store">'<tt>store</tt>' Instruction</a>
4487</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4488
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4489<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4490
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4491<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4492<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4493 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>
4494 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]4495</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4496
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4497<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4498<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4499
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4500<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4501<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4502 and an address at which to store it. The type of the
4503 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4504 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4505 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4506 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4507 order of execution of this <tt>store</tt> with other <a
4508 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4509
4510<p>The optional constant "align" argument specifies the alignment of the
4511 operation (that is, the alignment of the memory address). A value of 0 or an
4512 omitted "align" argument means that the operation has the preferential
4513 alignment for the target. It is the responsibility of the code emitter to
4514 ensure that the alignment information is correct. Overestimating the
4515 alignment results in an undefined behavior. Underestimating the alignment may
4516 produce less efficient code. An alignment of 1 is always safe.</p>
4517
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4518<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4519 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4520 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4521 instruction tells the optimizer and code generator that this load is
4522 not expected to be reused in the cache. The code generator may
4523 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4524 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4525
4526
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4527<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4528<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4529 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4530 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4531 does not exceed the minimum number of bytes needed to hold all bits of the
4532 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4533 writing a value of a type like <tt>i20</tt> with a size that is not an
4534 integral number of bytes, it is unspecified what happens to the extra bits
4535 that do not belong to the type, but they will typically be overwritten.</p>
4536
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4537<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4538<pre>
4539 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4540 store i32 3, i32* %ptr <i>; yields {void}</i>
4541 %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]4542</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4543
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4544</div>
4545
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4546<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4547<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4548 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4549</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4550
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4551<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4552
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4553<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4554<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4555 &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]4556 &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]4557</pre>
4558
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4559<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4560<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4561 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4562 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4563
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4564<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4565<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4566 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4567 elements of the aggregate object are indexed. The interpretation of each
4568 index is dependent on the type being indexed into. The first index always
4569 indexes the pointer value given as the first argument, the second index
4570 indexes a value of the type pointed to (not necessarily the value directly
4571 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4572 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4573 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4574 can never be pointers, since that would require loading the pointer before
4575 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4576
4577<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]4578 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4579 integer <b>constants</b> are allowed. When indexing into an array, pointer
4580 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]4581 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4582
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4583<p>For example, let's consider a C code fragment and how it gets compiled to
4584 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4585
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4586<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4587struct RT {
4588 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4589 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4590 char C;
4591};
4592struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4593 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4594 double Y;
4595 struct RT Z;
4596};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4597
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4598int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4599 return &amp;s[1].Z.B[5][13];
4600}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4601</pre>
4602
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4603<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4604
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4605<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4606%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4607%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4608
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4609define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4610entry:
4611 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4612 ret i32* %reg
4613}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4614</pre>
4615
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4616<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4617<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]4618 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4619 }</tt>' type, a structure. The second index indexes into the third element
4620 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4621 i8 }</tt>' type, another structure. The third index indexes into the second
4622 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4623 array. The two dimensions of the array are subscripted into, yielding an
4624 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4625 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4626
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4627<p>Note that it is perfectly legal to index partially through a structure,
4628 returning a pointer to an inner element. Because of this, the LLVM code for
4629 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4630
4631<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4632 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4633 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4634 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4635 %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]4636 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4637 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4638 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4639 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4640</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4641
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4642<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4643 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4644 base pointer is not an <i>in bounds</i> address of an allocated object,
4645 or if any of the addresses that would be formed by successive addition of
4646 the offsets implied by the indices to the base address with infinitely
4647 precise arithmetic are not an <i>in bounds</i> address of that allocated
4648 object. The <i>in bounds</i> addresses for an allocated object are all
4649 the addresses that point into the object, plus the address one byte past
4650 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4651
4652<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4653 the base address with silently-wrapping two's complement arithmetic, and
4654 the result value of the <tt>getelementptr</tt> may be outside the object
4655 pointed to by the base pointer. The result value may not necessarily be
4656 used to access memory though, even if it happens to point into allocated
4657 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4658 section for more information.</p>
4659
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4660<p>The getelementptr instruction is often confusing. For some more insight into
4661 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4662
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4663<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4664<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4665 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4666 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4667 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4668 %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]4669 <i>; yields i8*:eptr</i>
4670 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4671 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4672 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4673</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4674
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4675</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4676
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4677</div>
4678
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4679<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4680<h3>
4681 <a name="convertops">Conversion Operations</a>
4682</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4683
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4684<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4685
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4686<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4687 which all take a single operand and a type. They perform various bit
4688 conversions on the operand.</p>
4689
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4690<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4691<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4692 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4693</h4>
4694
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4695<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4696
4697<h5>Syntax:</h5>
4698<pre>
4699 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4700</pre>
4701
4702<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4703<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4704 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4705
4706<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4707<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4708 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4709 of the same number of integers.
4710 The bit size of the <tt>value</tt> must be larger than
4711 the bit size of the destination type, <tt>ty2</tt>.
4712 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4713
4714<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4715<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4716 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4717 source size must be larger than the destination size, <tt>trunc</tt> cannot
4718 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4719
4720<h5>Example:</h5>
4721<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4722 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4723 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4724 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4725 %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]4726</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4727
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4728</div>
4729
4730<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4731<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4732 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4733</h4>
4734
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4735<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4736
4737<h5>Syntax:</h5>
4738<pre>
4739 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4740</pre>
4741
4742<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4743<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4744 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4745
4746
4747<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4748<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4749 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4750 of the same number of integers.
4751 The bit size of the <tt>value</tt> must be smaller than
4752 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4753 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4754
4755<h5>Semantics:</h5>
4756<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]4757 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4758
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4759<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]4760
4761<h5>Example:</h5>
4762<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4763 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4764 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4765 %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]4766</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4767
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4768</div>
4769
4770<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4771<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4772 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4773</h4>
4774
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4775<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4776
4777<h5>Syntax:</h5>
4778<pre>
4779 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4780</pre>
4781
4782<h5>Overview:</h5>
4783<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4784
4785<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4786<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4787 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4788 of the same number of integers.
4789 The bit size of the <tt>value</tt> must be smaller than
4790 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4791 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4792
4793<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4794<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4795 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4796 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4797
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4798<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]4799
4800<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4801<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4802 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4803 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4804 %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]4805</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4806
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4807</div>
4808
4809<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4810<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4811 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4812</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4813
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4814<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4815
4816<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4817<pre>
4818 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4819</pre>
4820
4821<h5>Overview:</h5>
4822<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4823 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4824
4825<h5>Arguments:</h5>
4826<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4827 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4828 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]4829 <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]4830 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4831
4832<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4833<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4834 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4835 <a href="#t_floating">floating point</a> type. If the value cannot fit
4836 within the destination type, <tt>ty2</tt>, then the results are
4837 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4838
4839<h5>Example:</h5>
4840<pre>
4841 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4842 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4843</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4844
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4845</div>
4846
4847<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4848<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4849 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4850</h4>
4851
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4852<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4853
4854<h5>Syntax:</h5>
4855<pre>
4856 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4857</pre>
4858
4859<h5>Overview:</h5>
4860<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]4861 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4862
4863<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4864<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4865 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4866 a <a href="#t_floating">floating point</a> type to cast it to. The source
4867 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4868
4869<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4870<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4871 <a href="#t_floating">floating point</a> type to a larger
4872 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4873 used to make a <i>no-op cast</i> because it always changes bits. Use
4874 <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]4875
4876<h5>Example:</h5>
4877<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]4878 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4879 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4880</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4881
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4882</div>
4883
4884<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4885<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4886 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4887</h4>
4888
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4889<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4890
4891<h5>Syntax:</h5>
4892<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4893 &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]4894</pre>
4895
4896<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4897<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4898 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4899
4900<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4901<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4902 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4903 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4904 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4905 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4906
4907<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4908<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4909 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4910 towards zero) unsigned integer value. If the value cannot fit
4911 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4912
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4913<h5>Example:</h5>
4914<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4915 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4916 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4917 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4918</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4919
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4920</div>
4921
4922<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4923<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4924 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4925</h4>
4926
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4927<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4928
4929<h5>Syntax:</h5>
4930<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4931 &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]4932</pre>
4933
4934<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4935<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4936 <a href="#t_floating">floating point</a> <tt>value</tt> to
4937 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4938
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4939<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4940<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4941 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4942 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4943 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4944 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4945
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4946<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4947<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4948 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4949 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4950 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4951
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4952<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4953<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4954 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4955 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4956 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4957</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4958
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4959</div>
4960
4961<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4962<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4963 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4964</h4>
4965
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4966<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4967
4968<h5>Syntax:</h5>
4969<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4970 &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]4971</pre>
4972
4973<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4974<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4975 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4976
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4977<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4978<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]4979 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4980 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4981 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4982 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4983
4984<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4985<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4986 integer quantity and converts it to the corresponding floating point
4987 value. If the value cannot fit in the floating point value, the results are
4988 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4989
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4990<h5>Example:</h5>
4991<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4992 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4993 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4994</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4995
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4996</div>
4997
4998<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4999<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5000 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5001</h4>
5002
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5003<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5004
5005<h5>Syntax:</h5>
5006<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5007 &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]5008</pre>
5009
5010<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5011<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5012 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5013
5014<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5015<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]5016 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5017 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5018 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5019 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5020
5021<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5022<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5023 quantity and converts it to the corresponding floating point value. If the
5024 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5025
5026<h5>Example:</h5>
5027<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5028 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5029 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5030</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5031
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5032</div>
5033
5034<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5035<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5036 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5037</h4>
5038
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5039<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5040
5041<h5>Syntax:</h5>
5042<pre>
5043 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5044</pre>
5045
5046<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5047<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5048 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5049
5050<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5051<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5052 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5053 <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]5054
5055<h5>Semantics:</h5>
5056<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5057 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5058 truncating or zero extending that value to the size of the integer type. If
5059 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5060 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5061 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5062 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5063
5064<h5>Example:</h5>
5065<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5066 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5067 %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]5068</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5069
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5070</div>
5071
5072<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5073<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5074 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5075</h4>
5076
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5077<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5078
5079<h5>Syntax:</h5>
5080<pre>
5081 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5082</pre>
5083
5084<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5085<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5086 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5087
5088<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5089<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5090 value to cast, and a type to cast it to, which must be a
5091 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5092
5093<h5>Semantics:</h5>
5094<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5095 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5096 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5097 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5098 than the size of a pointer then a zero extension is done. If they are the
5099 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5100
5101<h5>Example:</h5>
5102<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5103 %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]5104 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5105 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5106</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5107
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5108</div>
5109
5110<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5111<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5112 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5113</h4>
5114
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5115<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5116
5117<h5>Syntax:</h5>
5118<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5119 &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]5120</pre>
5121
5122<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5123<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5124 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5125
5126<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5127<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5128 non-aggregate first class value, and a type to cast it to, which must also be
5129 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5130 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5131 identical. If the source type is a pointer, the destination type must also be
5132 a pointer. This instruction supports bitwise conversion of vectors to
5133 integers and to vectors of other types (as long as they have the same
5134 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5135
5136<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5137<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5138 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5139 this conversion. The conversion is done as if the <tt>value</tt> had been
5140 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5141 be converted to other pointer types with this instruction. To convert
5142 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5143 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5144
5145<h5>Example:</h5>
5146<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5147 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5148 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5149 %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]5150</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5151
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5152</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5153
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5154</div>
5155
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5156<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5157<h3>
5158 <a name="otherops">Other Operations</a>
5159</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5160
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5161<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5162
5163<p>The instructions in this category are the "miscellaneous" instructions, which
5164 defy better classification.</p>
5165
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5166<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5167<h4>
5168 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5169</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5170
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5171<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5172
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5173<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5174<pre>
5175 &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]5176</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5177
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5178<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5179<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5180 boolean values based on comparison of its two integer, integer vector, or
5181 pointer operands.</p>
5182
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5183<h5>Arguments:</h5>
5184<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5185 the condition code indicating the kind of comparison to perform. It is not a
5186 value, just a keyword. The possible condition code are:</p>
5187
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5188<ol>
5189 <li><tt>eq</tt>: equal</li>
5190 <li><tt>ne</tt>: not equal </li>
5191 <li><tt>ugt</tt>: unsigned greater than</li>
5192 <li><tt>uge</tt>: unsigned greater or equal</li>
5193 <li><tt>ult</tt>: unsigned less than</li>
5194 <li><tt>ule</tt>: unsigned less or equal</li>
5195 <li><tt>sgt</tt>: signed greater than</li>
5196 <li><tt>sge</tt>: signed greater or equal</li>
5197 <li><tt>slt</tt>: signed less than</li>
5198 <li><tt>sle</tt>: signed less or equal</li>
5199</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5200
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5201<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5202 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5203 typed. They must also be identical types.</p>
5204
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5205<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5206<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5207 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5208 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]5209 result, as follows:</p>
5210
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5211<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5212 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5213 <tt>false</tt> otherwise. No sign interpretation is necessary or
5214 performed.</li>
5215
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5216 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5217 <tt>false</tt> otherwise. No sign interpretation is necessary or
5218 performed.</li>
5219
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5220 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5221 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5222
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5223 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5224 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5225 to <tt>op2</tt>.</li>
5226
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5227 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5228 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5229
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5230 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5231 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5232
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5233 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5234 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5235
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5236 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5237 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5238 to <tt>op2</tt>.</li>
5239
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5240 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5241 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5242
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5243 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5244 <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]5245</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5246
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5247<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5248 values are compared as if they were integers.</p>
5249
5250<p>If the operands are integer vectors, then they are compared element by
5251 element. The result is an <tt>i1</tt> vector with the same number of elements
5252 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5253
5254<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5255<pre>
5256 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5257 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5258 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5259 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5260 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5261 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5262</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5263
5264<p>Note that the code generator does not yet support vector types with
5265 the <tt>icmp</tt> instruction.</p>
5266
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5267</div>
5268
5269<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5270<h4>
5271 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5272</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5273
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5274<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5275
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5276<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5277<pre>
5278 &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]5279</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5280
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5281<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5282<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5283 values based on comparison of its operands.</p>
5284
5285<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]5286(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5287
5288<p>If the operands are floating point vectors, then the result type is a vector
5289 of boolean with the same number of elements as the operands being
5290 compared.</p>
5291
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5292<h5>Arguments:</h5>
5293<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5294 the condition code indicating the kind of comparison to perform. It is not a
5295 value, just a keyword. The possible condition code are:</p>
5296
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5297<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5298 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5299 <li><tt>oeq</tt>: ordered and equal</li>
5300 <li><tt>ogt</tt>: ordered and greater than </li>
5301 <li><tt>oge</tt>: ordered and greater than or equal</li>
5302 <li><tt>olt</tt>: ordered and less than </li>
5303 <li><tt>ole</tt>: ordered and less than or equal</li>
5304 <li><tt>one</tt>: ordered and not equal</li>
5305 <li><tt>ord</tt>: ordered (no nans)</li>
5306 <li><tt>ueq</tt>: unordered or equal</li>
5307 <li><tt>ugt</tt>: unordered or greater than </li>
5308 <li><tt>uge</tt>: unordered or greater than or equal</li>
5309 <li><tt>ult</tt>: unordered or less than </li>
5310 <li><tt>ule</tt>: unordered or less than or equal</li>
5311 <li><tt>une</tt>: unordered or not equal</li>
5312 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5313 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5314</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5315
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5316<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5317 <i>unordered</i> means that either operand may be a QNAN.</p>
5318
5319<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5320 a <a href="#t_floating">floating point</a> type or
5321 a <a href="#t_vector">vector</a> of floating point type. They must have
5322 identical types.</p>
5323
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5324<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5325<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5326 according to the condition code given as <tt>cond</tt>. If the operands are
5327 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5328 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5329 follows:</p>
5330
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5331<ol>
5332 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5333
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5334 <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]5335 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5336
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5337 <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]5338 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5339
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5340 <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]5341 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5342
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5343 <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]5344 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5345
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5346 <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]5347 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5348
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5349 <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]5350 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5351
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5352 <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]5353
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5354 <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]5355 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5356
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5357 <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]5358 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5359
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5360 <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]5361 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5362
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5363 <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]5364 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5365
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5366 <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]5367 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5368
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5369 <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]5370 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5371
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5372 <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]5373
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5374 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5375</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5376
5377<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5378<pre>
5379 &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]5380 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5381 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5382 &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]5383</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5384
5385<p>Note that the code generator does not yet support vector types with
5386 the <tt>fcmp</tt> instruction.</p>
5387
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5388</div>
5389
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5390<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5391<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5392 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5393</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5394
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5395<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5396
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5397<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5398<pre>
5399 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5400</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5401
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5402<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5403<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5404 SSA graph representing the function.</p>
5405
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5406<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5407<p>The type of the incoming values is specified with the first type field. After
5408 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5409 one pair for each predecessor basic block of the current block. Only values
5410 of <a href="#t_firstclass">first class</a> type may be used as the value
5411 arguments to the PHI node. Only labels may be used as the label
5412 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5413
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5414<p>There must be no non-phi instructions between the start of a basic block and
5415 the PHI instructions: i.e. PHI instructions must be first in a basic
5416 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5417
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5418<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5419 occur on the edge from the corresponding predecessor block to the current
5420 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5421 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5422
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5423<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5424<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5425 specified by the pair corresponding to the predecessor basic block that
5426 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5427
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5428<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5429<pre>
5430Loop: ; Infinite loop that counts from 0 on up...
5431 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5432 %nextindvar = add i32 %indvar, 1
5433 br label %Loop
5434</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5435
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5436</div>
5437
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5438<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5439<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5440 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5441</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5442
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5443<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5444
5445<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5446<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5447 &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>
5448
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5449 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5450</pre>
5451
5452<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5453<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5454 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5455
5456
5457<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5458<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5459 values indicating the condition, and two values of the
5460 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5461 vectors and the condition is a scalar, then entire vectors are selected, not
5462 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5463
5464<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5465<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5466 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5467
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5468<p>If the condition is a vector of i1, then the value arguments must be vectors
5469 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5470
5471<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5472<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5473 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5474</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5475
5476<p>Note that the code generator does not yet support conditions
5477 with vector type.</p>
5478
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5479</div>
5480
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5481<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5482<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5483 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5484</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5485
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5486<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5487
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5488<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5489<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5490 &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]5491</pre>
5492
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5493<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5494<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5495
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5496<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5497<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5498
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5499<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5500 <li>The optional "tail" marker indicates that the callee function does not
5501 access any allocas or varargs in the caller. Note that calls may be
5502 marked "tail" even if they do not occur before
5503 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5504 present, the function call is eligible for tail call optimization,
5505 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5506 optimized into a jump</a>. The code generator may optimize calls marked
5507 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5508 sibling call optimization</a> when the caller and callee have
5509 matching signatures, or 2) forced tail call optimization when the
5510 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5511 <ul>
5512 <li>Caller and callee both have the calling
5513 convention <tt>fastcc</tt>.</li>
5514 <li>The call is in tail position (ret immediately follows call and ret
5515 uses value of call or is void).</li>
5516 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5517 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5518 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5519 constraints are met.</a></li>
5520 </ul>
5521 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5522
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5523 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5524 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5525 defaults to using C calling conventions. The calling convention of the
5526 call must match the calling convention of the target function, or else the
5527 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5528
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5529 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5530 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5531 '<tt>inreg</tt>' attributes are valid here.</li>
5532
5533 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5534 type of the return value. Functions that return no value are marked
5535 <tt><a href="#t_void">void</a></tt>.</li>
5536
5537 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5538 being invoked. The argument types must match the types implied by this
5539 signature. This type can be omitted if the function is not varargs and if
5540 the function type does not return a pointer to a function.</li>
5541
5542 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5543 be invoked. In most cases, this is a direct function invocation, but
5544 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5545 to function value.</li>
5546
5547 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5548 signature argument types and parameter attributes. All arguments must be
5549 of <a href="#t_firstclass">first class</a> type. If the function
5550 signature indicates the function accepts a variable number of arguments,
5551 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5552
5553 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5554 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5555 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5556</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5557
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5558<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5559<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5560 a specified function, with its incoming arguments bound to the specified
5561 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5562 function, control flow continues with the instruction after the function
5563 call, and the return value of the function is bound to the result
5564 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5565
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5566<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5567<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5568 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5569 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5570 %X = tail call i32 @foo() <i>; yields i32</i>
5571 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5572 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5573
5574 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5575 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5576 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5577 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5578 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5579 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5580</pre>
5581
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5582<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5583standard C99 library as being the C99 library functions, and may perform
5584optimizations or generate code for them under that assumption. This is
5585something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5586freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5587
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5588</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5589
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5590<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5591<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5592 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5593</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5594
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5595<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5596
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5597<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5598<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5599 &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]5600</pre>
5601
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5602<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5603<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5604 the "variable argument" area of a function call. It is used to implement the
5605 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5606
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5607<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5608<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5609 argument. It returns a value of the specified argument type and increments
5610 the <tt>va_list</tt> to point to the next argument. The actual type
5611 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5612
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5613<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5614<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5615 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5616 to the next argument. For more information, see the variable argument
5617 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5618
5619<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]5620 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5621 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5622
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5623<p><tt>va_arg</tt> is an LLVM instruction instead of
5624 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5625 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5626
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5627<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5628<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5629
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5630<p>Note that the code generator does not yet fully support va_arg on many
5631 targets. Also, it does not currently support va_arg with aggregate types on
5632 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5633
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5634</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5635
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5636</div>
5637
5638</div>
5639
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5640<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5641<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5642<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5643
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5644<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5645
5646<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5647 well known names and semantics and are required to follow certain
5648 restrictions. Overall, these intrinsics represent an extension mechanism for
5649 the LLVM language that does not require changing all of the transformations
5650 in LLVM when adding to the language (or the bitcode reader/writer, the
5651 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5652
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5653<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5654 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5655 begin with this prefix. Intrinsic functions must always be external
5656 functions: you cannot define the body of intrinsic functions. Intrinsic
5657 functions may only be used in call or invoke instructions: it is illegal to
5658 take the address of an intrinsic function. Additionally, because intrinsic
5659 functions are part of the LLVM language, it is required if any are added that
5660 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5661
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5662<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5663 family of functions that perform the same operation but on different data
5664 types. Because LLVM can represent over 8 million different integer types,
5665 overloading is used commonly to allow an intrinsic function to operate on any
5666 integer type. One or more of the argument types or the result type can be
5667 overloaded to accept any integer type. Argument types may also be defined as
5668 exactly matching a previous argument's type or the result type. This allows
5669 an intrinsic function which accepts multiple arguments, but needs all of them
5670 to be of the same type, to only be overloaded with respect to a single
5671 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5672
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5673<p>Overloaded intrinsics will have the names of its overloaded argument types
5674 encoded into its function name, each preceded by a period. Only those types
5675 which are overloaded result in a name suffix. Arguments whose type is matched
5676 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5677 can take an integer of any width and returns an integer of exactly the same
5678 integer width. This leads to a family of functions such as
5679 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5680 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5681 suffix is required. Because the argument's type is matched against the return
5682 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5683
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5684<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5685 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5686
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5687<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5688<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5689 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5690</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5691
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5692<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5693
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5694<p>Variable argument support is defined in LLVM with
5695 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5696 intrinsic functions. These functions are related to the similarly named
5697 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5698
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5699<p>All of these functions operate on arguments that use a target-specific value
5700 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5701 not define what this type is, so all transformations should be prepared to
5702 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5703
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5704<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]5705 instruction and the variable argument handling intrinsic functions are
5706 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5707
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5708<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5709define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5710 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5711 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5712 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5713 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5714
5715 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5716 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5717
5718 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5719 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5720 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5721 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5722 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5723
5724 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5725 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5726 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5727}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5728
5729declare void @llvm.va_start(i8*)
5730declare void @llvm.va_copy(i8*, i8*)
5731declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5732</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5733
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5734<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5735<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5736 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5737</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5738
5739
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5740<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5741
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5742<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5743<pre>
5744 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5745</pre>
5746
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5747<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5748<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5749 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]5750
5751<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5752<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]5753
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5754<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5755<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]5756 macro available in C. In a target-dependent way, it initializes
5757 the <tt>va_list</tt> element to which the argument points, so that the next
5758 call to <tt>va_arg</tt> will produce the first variable argument passed to
5759 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5760 need to know the last argument of the function as the compiler can figure
5761 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5762
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5763</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5764
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5765<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5766<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5767 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5768</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5769
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5770<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5771
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5772<h5>Syntax:</h5>
5773<pre>
5774 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5775</pre>
5776
5777<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5778<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5779 which has been initialized previously
5780 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5781 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5782
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5783<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5784<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]5785
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5786<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5787<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]5788 macro available in C. In a target-dependent way, it destroys
5789 the <tt>va_list</tt> element to which the argument points. Calls
5790 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5791 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5792 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5793
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5794</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5795
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5796<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5797<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5798 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5799</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5800
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5801<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5802
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5803<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5804<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5805 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5806</pre>
5807
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5808<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5809<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5810 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5811
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5812<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5813<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]5814 The second argument is a pointer to a <tt>va_list</tt> element to copy
5815 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5816
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5817<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5818<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]5819 macro available in C. In a target-dependent way, it copies the
5820 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5821 element. This intrinsic is necessary because
5822 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5823 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5824
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5825</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5826
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5827</div>
5828
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5829<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5830<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5831 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5832</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5833
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5834<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5835
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5836<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5837Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5838intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5839roots on the stack</a>, as well as garbage collector implementations that
5840require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5841barriers. Front-ends for type-safe garbage collected languages should generate
5842these intrinsics to make use of the LLVM garbage collectors. For more details,
5843see <a href="GarbageCollection.html">Accurate Garbage Collection with
5844LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5845
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5846<p>The garbage collection intrinsics only operate on objects in the generic
5847 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5848
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5849<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5850<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5851 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5852</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5853
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5854<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5855
5856<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5857<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5858 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5859</pre>
5860
5861<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5862<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]5863 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5864
5865<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5866<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5867 root pointer. The second pointer (which must be either a constant or a
5868 global value address) contains the meta-data to be associated with the
5869 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5870
5871<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5872<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]5873 location. At compile-time, the code generator generates information to allow
5874 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5875 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5876 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5877
5878</div>
5879
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5880<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5881<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5882 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5883</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5884
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5885<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5886
5887<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5888<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5889 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5890</pre>
5891
5892<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5893<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5894 locations, allowing garbage collector implementations that require read
5895 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5896
5897<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5898<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]5899 allocated from the garbage collector. The first object is a pointer to the
5900 start of the referenced object, if needed by the language runtime (otherwise
5901 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5902
5903<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5904<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5905 instruction, but may be replaced with substantially more complex code by the
5906 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5907 may only be used in a function which <a href="#gc">specifies a GC
5908 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5909
5910</div>
5911
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5912<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5913<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5914 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5915</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5916
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5917<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5918
5919<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5920<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5921 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5922</pre>
5923
5924<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5925<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5926 locations, allowing garbage collector implementations that require write
5927 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5928
5929<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5930<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]5931 object to store it to, and the third is the address of the field of Obj to
5932 store to. If the runtime does not require a pointer to the object, Obj may
5933 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5934
5935<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5936<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5937 instruction, but may be replaced with substantially more complex code by the
5938 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5939 may only be used in a function which <a href="#gc">specifies a GC
5940 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5941
5942</div>
5943
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5944</div>
5945
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5946<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5947<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5948 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5949</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5950
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5951<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5952
5953<p>These intrinsics are provided by LLVM to expose special features that may
5954 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5955
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5956<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5957<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5958 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5959</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5960
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5961<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5962
5963<h5>Syntax:</h5>
5964<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5965 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5966</pre>
5967
5968<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5969<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5970 target-specific value indicating the return address of the current function
5971 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5972
5973<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5974<p>The argument to this intrinsic indicates which function to return the address
5975 for. Zero indicates the calling function, one indicates its caller, etc.
5976 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5977
5978<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5979<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5980 indicating the return address of the specified call frame, or zero if it
5981 cannot be identified. The value returned by this intrinsic is likely to be
5982 incorrect or 0 for arguments other than zero, so it should only be used for
5983 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5984
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5985<p>Note that calling this intrinsic does not prevent function inlining or other
5986 aggressive transformations, so the value returned may not be that of the
5987 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5988
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5989</div>
5990
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5991<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5992<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5993 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5994</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5995
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5996<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5997
5998<h5>Syntax:</h5>
5999<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6000 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6001</pre>
6002
6003<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6004<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6005 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6006
6007<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6008<p>The argument to this intrinsic indicates which function to return the frame
6009 pointer for. Zero indicates the calling function, one indicates its caller,
6010 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6011
6012<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6013<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6014 indicating the frame address of the specified call frame, or zero if it
6015 cannot be identified. The value returned by this intrinsic is likely to be
6016 incorrect or 0 for arguments other than zero, so it should only be used for
6017 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6018
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6019<p>Note that calling this intrinsic does not prevent function inlining or other
6020 aggressive transformations, so the value returned may not be that of the
6021 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6022
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6023</div>
6024
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6025<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6026<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6027 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6028</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6029
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6030<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6031
6032<h5>Syntax:</h5>
6033<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6034 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6035</pre>
6036
6037<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6038<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6039 of the function stack, for use
6040 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6041 useful for implementing language features like scoped automatic variable
6042 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6043
6044<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6045<p>This intrinsic returns a opaque pointer value that can be passed
6046 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6047 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6048 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6049 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6050 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6051 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6052
6053</div>
6054
6055<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6056<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6057 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6058</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6059
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6060<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6061
6062<h5>Syntax:</h5>
6063<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6064 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6065</pre>
6066
6067<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6068<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6069 the function stack to the state it was in when the
6070 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6071 executed. This is useful for implementing language features like scoped
6072 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6073
6074<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6075<p>See the description
6076 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6077
6078</div>
6079
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6080<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6081<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6082 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6083</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6084
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6085<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6086
6087<h5>Syntax:</h5>
6088<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6089 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]6090</pre>
6091
6092<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6093<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6094 insert a prefetch instruction if supported; otherwise, it is a noop.
6095 Prefetches have no effect on the behavior of the program but can change its
6096 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6097
6098<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6099<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6100 specifier determining if the fetch should be for a read (0) or write (1),
6101 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6102 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6103 specifies whether the prefetch is performed on the data (1) or instruction (0)
6104 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6105 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6106
6107<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6108<p>This intrinsic does not modify the behavior of the program. In particular,
6109 prefetches cannot trap and do not produce a value. On targets that support
6110 this intrinsic, the prefetch can provide hints to the processor cache for
6111 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6112
6113</div>
6114
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6115<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6116<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6117 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6118</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6119
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6120<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6121
6122<h5>Syntax:</h5>
6123<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6124 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6125</pre>
6126
6127<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6128<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6129 Counter (PC) in a region of code to simulators and other tools. The method
6130 is target specific, but it is expected that the marker will use exported
6131 symbols to transmit the PC of the marker. The marker makes no guarantees
6132 that it will remain with any specific instruction after optimizations. It is
6133 possible that the presence of a marker will inhibit optimizations. The
6134 intended use is to be inserted after optimizations to allow correlations of
6135 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6136
6137<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6138<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6139
6140<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6141<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6142 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6143
6144</div>
6145
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6146<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6147<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6148 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6149</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6150
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6151<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6152
6153<h5>Syntax:</h5>
6154<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6155 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6156</pre>
6157
6158<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6159<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6160 counter register (or similar low latency, high accuracy clocks) on those
6161 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6162 should map to RPCC. As the backing counters overflow quickly (on the order
6163 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6164
6165<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6166<p>When directly supported, reading the cycle counter should not modify any
6167 memory. Implementations are allowed to either return a application specific
6168 value or a system wide value. On backends without support, this is lowered
6169 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6170
6171</div>
6172
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6173</div>
6174
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6175<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6176<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6177 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6178</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6179
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6180<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6181
6182<p>LLVM provides intrinsics for a few important standard C library functions.
6183 These intrinsics allow source-language front-ends to pass information about
6184 the alignment of the pointer arguments to the code generator, providing
6185 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6186
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6187<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6188<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6189 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6190</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6191
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6192<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6193
6194<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6195<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]6196 integer bit width and for different address spaces. Not all targets support
6197 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6198
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6199<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6200 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]6201 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6202 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]6203 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6204</pre>
6205
6206<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6207<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6208 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6209
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6210<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6211 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6212 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6213
6214<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6215
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6216<p>The first argument is a pointer to the destination, the second is a pointer
6217 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6218 number of bytes to copy, the fourth argument is the alignment of the
6219 source and destination locations, and the fifth is a boolean indicating a
6220 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6221
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6222<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]6223 then the caller guarantees that both the source and destination pointers are
6224 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6225
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6226<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6227 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6228 The detailed access behavior is not very cleanly specified and it is unwise
6229 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6230
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6231<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6232
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6233<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6234 source location to the destination location, which are not allowed to
6235 overlap. It copies "len" bytes of memory over. If the argument is known to
6236 be aligned to some boundary, this can be specified as the fourth argument,
6237 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6238
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6239</div>
6240
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6241<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6242<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6243 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6244</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6245
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6246<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6247
6248<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6249<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]6250 width and for different address space. Not all targets support all bit
6251 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6252
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6253<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6254 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]6255 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6256 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]6257 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6258</pre>
6259
6260<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6261<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6262 source location to the destination location. It is similar to the
6263 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6264 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6265
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6266<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6267 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6268 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6269
6270<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6271
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6272<p>The first argument is a pointer to the destination, the second is a pointer
6273 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6274 number of bytes to copy, the fourth argument is the alignment of the
6275 source and destination locations, and the fifth is a boolean indicating a
6276 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6277
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6278<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]6279 then the caller guarantees that the source and destination pointers are
6280 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6281
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6282<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6283 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6284 The detailed access behavior is not very cleanly specified and it is unwise
6285 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6286
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6287<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6288
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6289<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6290 source location to the destination location, which may overlap. It copies
6291 "len" bytes of memory over. If the argument is known to be aligned to some
6292 boundary, this can be specified as the fourth argument, otherwise it should
6293 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6294
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6295</div>
6296
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6297<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6298<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6299 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6300</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6301
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6302<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6303
6304<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6305<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]6306 width and for different address spaces. However, not all targets support all
6307 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6308
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6309<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6310 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6311 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6312 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6313 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6314</pre>
6315
6316<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6317<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6318 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6319
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6320<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6321 intrinsic does not return a value and takes extra alignment/volatile
6322 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6323
6324<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6325<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]6326 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6327 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6328 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6329
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6330<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]6331 then the caller guarantees that the destination pointer is aligned to that
6332 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6333
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6334<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6335 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6336 The detailed access behavior is not very cleanly specified and it is unwise
6337 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6338
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6339<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6340<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6341 at the destination location. If the argument is known to be aligned to some
6342 boundary, this can be specified as the fourth argument, otherwise it should
6343 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6344
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6345</div>
6346
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6347<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6348<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6349 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6350</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6351
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6352<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6353
6354<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6355<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6356 floating point or vector of floating point type. Not all targets support all
6357 types however.</p>
6358
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6359<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6360 declare float @llvm.sqrt.f32(float %Val)
6361 declare double @llvm.sqrt.f64(double %Val)
6362 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6363 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6364 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6365</pre>
6366
6367<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6368<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6369 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6370 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6371 behavior for negative numbers other than -0.0 (which allows for better
6372 optimization, because there is no need to worry about errno being
6373 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]6374
6375<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6376<p>The argument and return value are floating point numbers of the same
6377 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6378
6379<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6380<p>This function returns the sqrt of the specified operand if it is a
6381 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6382
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6383</div>
6384
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6385<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6386<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6387 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6388</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6389
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6390<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6391
6392<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6393<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6394 floating point or vector of floating point type. Not all targets support all
6395 types however.</p>
6396
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6397<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6398 declare float @llvm.powi.f32(float %Val, i32 %power)
6399 declare double @llvm.powi.f64(double %Val, i32 %power)
6400 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6401 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6402 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6403</pre>
6404
6405<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6406<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6407 specified (positive or negative) power. The order of evaluation of
6408 multiplications is not defined. When a vector of floating point type is
6409 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6410
6411<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6412<p>The second argument is an integer power, and the first is a value to raise to
6413 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6414
6415<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6416<p>This function returns the first value raised to the second power with an
6417 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6418
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6419</div>
6420
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6421<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6422<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6423 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6424</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6425
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6426<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6427
6428<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6429<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6430 floating point or vector of floating point type. Not all targets support all
6431 types however.</p>
6432
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6433<pre>
6434 declare float @llvm.sin.f32(float %Val)
6435 declare double @llvm.sin.f64(double %Val)
6436 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6437 declare fp128 @llvm.sin.f128(fp128 %Val)
6438 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6439</pre>
6440
6441<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6442<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6443
6444<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6445<p>The argument and return value are floating point numbers of the same
6446 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6447
6448<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6449<p>This function returns the sine of the specified operand, returning the same
6450 values as the libm <tt>sin</tt> functions would, and handles error conditions
6451 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6452
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6453</div>
6454
6455<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6456<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6457 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6458</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6459
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6460<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6461
6462<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6463<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6464 floating point or vector of floating point type. Not all targets support all
6465 types however.</p>
6466
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6467<pre>
6468 declare float @llvm.cos.f32(float %Val)
6469 declare double @llvm.cos.f64(double %Val)
6470 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6471 declare fp128 @llvm.cos.f128(fp128 %Val)
6472 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6473</pre>
6474
6475<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6476<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6477
6478<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6479<p>The argument and return value are floating point numbers of the same
6480 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6481
6482<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6483<p>This function returns the cosine of the specified operand, returning the same
6484 values as the libm <tt>cos</tt> functions would, and handles error conditions
6485 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6486
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6487</div>
6488
6489<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6490<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6491 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6492</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6493
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6494<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6495
6496<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6497<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6498 floating point or vector of floating point type. Not all targets support all
6499 types however.</p>
6500
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6501<pre>
6502 declare float @llvm.pow.f32(float %Val, float %Power)
6503 declare double @llvm.pow.f64(double %Val, double %Power)
6504 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6505 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6506 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6507</pre>
6508
6509<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6510<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6511 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6512
6513<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6514<p>The second argument is a floating point power, and the first is a value to
6515 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6516
6517<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6518<p>This function returns the first value raised to the second power, returning
6519 the same values as the libm <tt>pow</tt> functions would, and handles error
6520 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6521
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6522</div>
6523
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6524</div>
6525
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6526<!-- _______________________________________________________________________ -->
6527<h4>
6528 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6529</h4>
6530
6531<div>
6532
6533<h5>Syntax:</h5>
6534<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6535 floating point or vector of floating point type. Not all targets support all
6536 types however.</p>
6537
6538<pre>
6539 declare float @llvm.exp.f32(float %Val)
6540 declare double @llvm.exp.f64(double %Val)
6541 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6542 declare fp128 @llvm.exp.f128(fp128 %Val)
6543 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6544</pre>
6545
6546<h5>Overview:</h5>
6547<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6548
6549<h5>Arguments:</h5>
6550<p>The argument and return value are floating point numbers of the same
6551 type.</p>
6552
6553<h5>Semantics:</h5>
6554<p>This function returns the same values as the libm <tt>exp</tt> functions
6555 would, and handles error conditions in the same way.</p>
6556
6557</div>
6558
6559<!-- _______________________________________________________________________ -->
6560<h4>
6561 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6562</h4>
6563
6564<div>
6565
6566<h5>Syntax:</h5>
6567<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6568 floating point or vector of floating point type. Not all targets support all
6569 types however.</p>
6570
6571<pre>
6572 declare float @llvm.log.f32(float %Val)
6573 declare double @llvm.log.f64(double %Val)
6574 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6575 declare fp128 @llvm.log.f128(fp128 %Val)
6576 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6577</pre>
6578
6579<h5>Overview:</h5>
6580<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6581
6582<h5>Arguments:</h5>
6583<p>The argument and return value are floating point numbers of the same
6584 type.</p>
6585
6586<h5>Semantics:</h5>
6587<p>This function returns the same values as the libm <tt>log</tt> functions
6588 would, and handles error conditions in the same way.</p>
6589
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6590<h4>
6591 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6592</h4>
6593
6594<div>
6595
6596<h5>Syntax:</h5>
6597<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6598 floating point or vector of floating point type. Not all targets support all
6599 types however.</p>
6600
6601<pre>
6602 declare float @llvm.fma.f32(float %a, float %b, float %c)
6603 declare double @llvm.fma.f64(double %a, double %b, double %c)
6604 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6605 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6606 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6607</pre>
6608
6609<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]6610<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6611 operation.</p>
6612
6613<h5>Arguments:</h5>
6614<p>The argument and return value are floating point numbers of the same
6615 type.</p>
6616
6617<h5>Semantics:</h5>
6618<p>This function returns the same values as the libm <tt>fma</tt> functions
6619 would.</p>
6620
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6621</div>
6622
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6623<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6624<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6625 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6626</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6627
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6628<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6629
6630<p>LLVM provides intrinsics for a few important bit manipulation operations.
6631 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6632
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6633<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6634<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6635 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6636</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6637
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6638<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6639
6640<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6641<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6642 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6643
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6644<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6645 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6646 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6647 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6648</pre>
6649
6650<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6651<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6652 values with an even number of bytes (positive multiple of 16 bits). These
6653 are useful for performing operations on data that is not in the target's
6654 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6655
6656<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6657<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6658 and low byte of the input i16 swapped. Similarly,
6659 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6660 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6661 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6662 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6663 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6664 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6665
6666</div>
6667
6668<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6669<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6670 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6671</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6672
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6673<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6674
6675<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6676<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]6677 width, or on any vector with integer elements. Not all targets support all
6678 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6679
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6680<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6681 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6682 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6683 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6684 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6685 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6686 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]6687</pre>
6688
6689<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6690<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6691 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6692
6693<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6694<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]6695 integer type, or a vector with integer elements.
6696 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6697
6698<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6699<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6700 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6701
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6702</div>
6703
6704<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6705<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6706 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6707</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6708
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6709<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6710
6711<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6712<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]6713 integer bit width, or any vector whose elements are integers. Not all
6714 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6715
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6716<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6717 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6718 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6719 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6720 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6721 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6722 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]6723</pre>
6724
6725<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6726<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6727 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6728
6729<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6730<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]6731 integer type, or any vector type with integer element type.
6732 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6733
6734<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6735<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6736 zeros in a variable, or within each element of the vector if the operation
6737 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]6738 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6739
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6740</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6741
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6742<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6743<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6744 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6745</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6746
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6747<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6748
6749<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6750<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]6751 integer bit width, or any vector of integer elements. Not all targets
6752 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6753
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6754<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6755 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6756 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6757 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6758 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6759 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6760 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]6761</pre>
6762
6763<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6764<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6765 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6766
6767<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6768<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]6769 integer type, or a vectory with integer element type.. The return type
6770 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6771
6772<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6773<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6774 zeros in a variable, or within each element of a vector.
6775 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6777
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6778</div>
6779
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6780</div>
6781
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6782<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6783<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6784 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6785</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6786
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6787<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6788
6789<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6790
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6791<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6792<h4>
6793 <a name="int_sadd_overflow">
6794 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6795 </a>
6796</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6797
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6798<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6799
6800<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6801<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]6802 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6803
6804<pre>
6805 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6806 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6807 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6808</pre>
6809
6810<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6811<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6812 a signed addition of the two arguments, and indicate whether an overflow
6813 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6814
6815<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6816<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]6817 be of integer types of any bit width, but they must have the same bit
6818 width. The second element of the result structure must be of
6819 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6820 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6821
6822<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6823<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6824 a signed addition of the two variables. They return a structure &mdash; the
6825 first element of which is the signed summation, and the second element of
6826 which is a bit specifying if the signed summation resulted in an
6827 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6828
6829<h5>Examples:</h5>
6830<pre>
6831 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6832 %sum = extractvalue {i32, i1} %res, 0
6833 %obit = extractvalue {i32, i1} %res, 1
6834 br i1 %obit, label %overflow, label %normal
6835</pre>
6836
6837</div>
6838
6839<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6840<h4>
6841 <a name="int_uadd_overflow">
6842 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6843 </a>
6844</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6845
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6846<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6847
6848<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6849<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]6850 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6851
6852<pre>
6853 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6854 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6855 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6856</pre>
6857
6858<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6859<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6860 an unsigned addition of the two arguments, and indicate whether a carry
6861 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6862
6863<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6864<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]6865 be of integer types of any bit width, but they must have the same bit
6866 width. The second element of the result structure must be of
6867 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6868 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6869
6870<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6871<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6872 an unsigned addition of the two arguments. They return a structure &mdash;
6873 the first element of which is the sum, and the second element of which is a
6874 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6875
6876<h5>Examples:</h5>
6877<pre>
6878 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6879 %sum = extractvalue {i32, i1} %res, 0
6880 %obit = extractvalue {i32, i1} %res, 1
6881 br i1 %obit, label %carry, label %normal
6882</pre>
6883
6884</div>
6885
6886<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6887<h4>
6888 <a name="int_ssub_overflow">
6889 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6890 </a>
6891</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6892
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6893<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6894
6895<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6896<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]6897 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6898
6899<pre>
6900 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6901 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6902 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6903</pre>
6904
6905<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6906<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6907 a signed subtraction of the two arguments, and indicate whether an overflow
6908 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6909
6910<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6911<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]6912 be of integer types of any bit width, but they must have the same bit
6913 width. The second element of the result structure must be of
6914 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6915 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6916
6917<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6918<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6919 a signed subtraction of the two arguments. They return a structure &mdash;
6920 the first element of which is the subtraction, and the second element of
6921 which is a bit specifying if the signed subtraction resulted in an
6922 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6923
6924<h5>Examples:</h5>
6925<pre>
6926 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6927 %sum = extractvalue {i32, i1} %res, 0
6928 %obit = extractvalue {i32, i1} %res, 1
6929 br i1 %obit, label %overflow, label %normal
6930</pre>
6931
6932</div>
6933
6934<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6935<h4>
6936 <a name="int_usub_overflow">
6937 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6938 </a>
6939</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6940
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6941<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6942
6943<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6944<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]6945 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6946
6947<pre>
6948 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6949 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6950 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6951</pre>
6952
6953<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6954<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6955 an unsigned subtraction of the two arguments, and indicate whether an
6956 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6957
6958<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6959<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]6960 be of integer types of any bit width, but they must have the same bit
6961 width. The second element of the result structure must be of
6962 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6963 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6964
6965<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6966<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6967 an unsigned subtraction of the two arguments. They return a structure &mdash;
6968 the first element of which is the subtraction, and the second element of
6969 which is a bit specifying if the unsigned subtraction resulted in an
6970 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6971
6972<h5>Examples:</h5>
6973<pre>
6974 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6975 %sum = extractvalue {i32, i1} %res, 0
6976 %obit = extractvalue {i32, i1} %res, 1
6977 br i1 %obit, label %overflow, label %normal
6978</pre>
6979
6980</div>
6981
6982<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6983<h4>
6984 <a name="int_smul_overflow">
6985 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6986 </a>
6987</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6988
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6989<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6990
6991<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6992<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]6993 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6994
6995<pre>
6996 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6997 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6998 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6999</pre>
7000
7001<h5>Overview:</h5>
7002
7003<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7004 a signed multiplication of the two arguments, and indicate whether an
7005 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7006
7007<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7008<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]7009 be of integer types of any bit width, but they must have the same bit
7010 width. The second element of the result structure must be of
7011 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7012 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7013
7014<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7015<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7016 a signed multiplication of the two arguments. They return a structure &mdash;
7017 the first element of which is the multiplication, and the second element of
7018 which is a bit specifying if the signed multiplication resulted in an
7019 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7020
7021<h5>Examples:</h5>
7022<pre>
7023 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7024 %sum = extractvalue {i32, i1} %res, 0
7025 %obit = extractvalue {i32, i1} %res, 1
7026 br i1 %obit, label %overflow, label %normal
7027</pre>
7028
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7029</div>
7030
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7031<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7032<h4>
7033 <a name="int_umul_overflow">
7034 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7035 </a>
7036</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7037
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7038<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7039
7040<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7041<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]7042 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7043
7044<pre>
7045 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7046 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7047 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7048</pre>
7049
7050<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7051<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7052 a unsigned multiplication of the two arguments, and indicate whether an
7053 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7054
7055<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7056<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]7057 be of integer types of any bit width, but they must have the same bit
7058 width. The second element of the result structure must be of
7059 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7060 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7061
7062<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7063<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7064 an unsigned multiplication of the two arguments. They return a structure
7065 &mdash; the first element of which is the multiplication, and the second
7066 element of which is a bit specifying if the unsigned multiplication resulted
7067 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7068
7069<h5>Examples:</h5>
7070<pre>
7071 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7072 %sum = extractvalue {i32, i1} %res, 0
7073 %obit = extractvalue {i32, i1} %res, 1
7074 br i1 %obit, label %overflow, label %normal
7075</pre>
7076
7077</div>
7078
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7079</div>
7080
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7081<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7082<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7083 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7084</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7085
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7086<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7087
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7088<p>Half precision floating point is a storage-only format. This means that it is
7089 a dense encoding (in memory) but does not support computation in the
7090 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7091
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7092<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7093 value as an i16, then convert it to float with <a
7094 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7095 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7096 double etc). To store the value back to memory, it is first converted to
7097 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7098 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7099 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7100
7101<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7102<h4>
7103 <a name="int_convert_to_fp16">
7104 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7105 </a>
7106</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7107
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7108<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7109
7110<h5>Syntax:</h5>
7111<pre>
7112 declare i16 @llvm.convert.to.fp16(f32 %a)
7113</pre>
7114
7115<h5>Overview:</h5>
7116<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7117 a conversion from single precision floating point format to half precision
7118 floating point format.</p>
7119
7120<h5>Arguments:</h5>
7121<p>The intrinsic function contains single argument - the value to be
7122 converted.</p>
7123
7124<h5>Semantics:</h5>
7125<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7126 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7127 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7128 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7129
7130<h5>Examples:</h5>
7131<pre>
7132 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7133 store i16 %res, i16* @x, align 2
7134</pre>
7135
7136</div>
7137
7138<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7139<h4>
7140 <a name="int_convert_from_fp16">
7141 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7142 </a>
7143</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7144
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7145<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7146
7147<h5>Syntax:</h5>
7148<pre>
7149 declare f32 @llvm.convert.from.fp16(i16 %a)
7150</pre>
7151
7152<h5>Overview:</h5>
7153<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7154 a conversion from half precision floating point format to single precision
7155 floating point format.</p>
7156
7157<h5>Arguments:</h5>
7158<p>The intrinsic function contains single argument - the value to be
7159 converted.</p>
7160
7161<h5>Semantics:</h5>
7162<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7163 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7164 precision floating point format. The input half-float value is represented by
7165 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7166
7167<h5>Examples:</h5>
7168<pre>
7169 %a = load i16* @x, align 2
7170 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7171</pre>
7172
7173</div>
7174
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7175</div>
7176
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7177<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7178<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7179 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7180</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7181
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7182<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7183
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7184<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7185 prefix), are described in
7186 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7187 Level Debugging</a> document.</p>
7188
7189</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7190
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7191<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7192<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7193 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7194</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7195
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7196<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7197
7198<p>The LLVM exception handling intrinsics (which all start with
7199 <tt>llvm.eh.</tt> prefix), are described in
7200 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7201 Handling</a> document.</p>
7202
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7203</div>
7204
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7205<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7206<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7207 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7208</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7209
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7210<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7211
7212<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7213 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7214 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7215 function pointer lacking the nest parameter - the caller does not need to
7216 provide a value for it. Instead, the value to use is stored in advance in a
7217 "trampoline", a block of memory usually allocated on the stack, which also
7218 contains code to splice the nest value into the argument list. This is used
7219 to implement the GCC nested function address extension.</p>
7220
7221<p>For example, if the function is
7222 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7223 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7224 follows:</p>
7225
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7226<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7227 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7228 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7229 %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]7230 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7231</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7232
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7233<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7234 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7235
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7236<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7237<h4>
7238 <a name="int_it">
7239 '<tt>llvm.init.trampoline</tt>' Intrinsic
7240 </a>
7241</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7242
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7243<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7244
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7245<h5>Syntax:</h5>
7246<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7247 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]7248</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7249
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7250<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7251<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7252 function pointer suitable for executing it.</p>
7253
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7254<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7255<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7256 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7257 sufficiently aligned block of memory; this memory is written to by the
7258 intrinsic. Note that the size and the alignment are target-specific - LLVM
7259 currently provides no portable way of determining them, so a front-end that
7260 generates this intrinsic needs to have some target-specific knowledge.
7261 The <tt>func</tt> argument must hold a function bitcast to
7262 an <tt>i8*</tt>.</p>
7263
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7264<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7265<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7266 dependent code, turning it into a function. A pointer to this function is
7267 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7268 function pointer type</a> before being called. The new function's signature
7269 is the same as that of <tt>func</tt> with any arguments marked with
7270 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7271 is allowed, and it must be of pointer type. Calling the new function is
7272 equivalent to calling <tt>func</tt> with the same argument list, but
7273 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7274 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7275 by <tt>tramp</tt> is modified, then the effect of any later call to the
7276 returned function pointer is undefined.</p>
7277
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7278</div>
7279
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7280</div>
7281
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7282<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7283<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7284 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7285</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7286
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7287<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7288
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7289<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7290 hardware constructs for atomic operations and memory synchronization. This
7291 provides an interface to the hardware, not an interface to the programmer. It
7292 is aimed at a low enough level to allow any programming models or APIs
7293 (Application Programming Interfaces) which need atomic behaviors to map
7294 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7295 hardware provides a "universal IR" for source languages, it also provides a
7296 starting point for developing a "universal" atomic operation and
7297 synchronization IR.</p>
7298
7299<p>These do <em>not</em> form an API such as high-level threading libraries,
7300 software transaction memory systems, atomic primitives, and intrinsic
7301 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7302 application libraries. The hardware interface provided by LLVM should allow
7303 a clean implementation of all of these APIs and parallel programming models.
7304 No one model or paradigm should be selected above others unless the hardware
7305 itself ubiquitously does so.</p>
7306
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7307<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7308<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7309 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7310</h4>
7311
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7312<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7313<h5>Syntax:</h5>
7314<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7315 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]7316</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7317
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7318<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7319<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7320 specific pairs of memory access types.</p>
7321
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7322<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7323<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7324 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7325 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7326 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7327
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7328<ul>
7329 <li><tt>ll</tt>: load-load barrier</li>
7330 <li><tt>ls</tt>: load-store barrier</li>
7331 <li><tt>sl</tt>: store-load barrier</li>
7332 <li><tt>ss</tt>: store-store barrier</li>
7333 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7334</ul>
7335
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7336<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7337<p>This intrinsic causes the system to enforce some ordering constraints upon
7338 the loads and stores of the program. This barrier does not
7339 indicate <em>when</em> any events will occur, it only enforces
7340 an <em>order</em> in which they occur. For any of the specified pairs of load
7341 and store operations (f.ex. load-load, or store-load), all of the first
7342 operations preceding the barrier will complete before any of the second
7343 operations succeeding the barrier begin. Specifically the semantics for each
7344 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7345
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7346<ul>
7347 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7348 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7349 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7350 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7351 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7352 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7353 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7354 load after the barrier begins.</li>
7355</ul>
7356
7357<p>These semantics are applied with a logical "and" behavior when more than one
7358 is enabled in a single memory barrier intrinsic.</p>
7359
7360<p>Backends may implement stronger barriers than those requested when they do
7361 not support as fine grained a barrier as requested. Some architectures do
7362 not need all types of barriers and on such architectures, these become
7363 noops.</p>
7364
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7365<h5>Example:</h5>
7366<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7367%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7368%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7369 store i32 4, %ptr
7370
7371%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7372 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]7373 <i>; guarantee the above finishes</i>
7374 store i32 8, %ptr <i>; before this begins</i>
7375</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7376
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7377</div>
7378
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7379<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7380<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7381 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7382</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7383
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7384<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7385
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7386<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7387<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7388 any integer bit width and for different address spaces. Not all targets
7389 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7390
7391<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7392 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7393 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7394 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7395 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]7396</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7397
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7398<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7399<p>This loads a value in memory and compares it to a given value. If they are
7400 equal, it stores a new value into the memory.</p>
7401
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7402<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7403<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7404 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7405 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7406 this integer type. While any bit width integer may be used, targets may only
7407 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7408
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7409<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7410<p>This entire intrinsic must be executed atomically. It first loads the value
7411 in memory pointed to by <tt>ptr</tt> and compares it with the
7412 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7413 memory. The loaded value is yielded in all cases. This provides the
7414 equivalent of an atomic compare-and-swap operation within the SSA
7415 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7416
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7417<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7418<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7419%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7420%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7421 store i32 4, %ptr
7422
7423%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7424%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7425 <i>; yields {i32}:result1 = 4</i>
7426%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7427%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7428
7429%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7430%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7431 <i>; yields {i32}:result2 = 8</i>
7432%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7433
7434%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7435</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7436
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7437</div>
7438
7439<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7440<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7441 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7442</h4>
7443
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7444<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7445<h5>Syntax:</h5>
7446
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7447<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7448 integer bit width. Not all targets support all bit widths however.</p>
7449
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7450<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7451 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7452 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7453 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7454 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]7455</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7456
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7457<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7458<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7459 the value from memory. It then stores the value in <tt>val</tt> in the memory
7460 at <tt>ptr</tt>.</p>
7461
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7462<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7463<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7464 the <tt>val</tt> argument and the result must be integers of the same bit
7465 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7466 integer type. The targets may only lower integer representations they
7467 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7468
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7469<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7470<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7471 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7472 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7473
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7474<h5>Examples:</h5>
7475<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7476%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7477%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7478 store i32 4, %ptr
7479
7480%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7481%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7482 <i>; yields {i32}:result1 = 4</i>
7483%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7484%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7485
7486%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7487%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7488 <i>; yields {i32}:result2 = 8</i>
7489
7490%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7491%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7492</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7493
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7494</div>
7495
7496<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7497<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7498 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7499</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7500
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7501<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7502
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7503<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7504<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7505 any integer bit width. Not all targets support all bit widths however.</p>
7506
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7507<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7508 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7509 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7510 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7511 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]7512</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7513
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7514<h5>Overview:</h5>
7515<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7516 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7517
7518<h5>Arguments:</h5>
7519<p>The intrinsic takes two arguments, the first a pointer to an integer value
7520 and the second an integer value. The result is also an integer value. These
7521 integer types can have any bit width, but they must all have the same bit
7522 width. The targets may only lower integer representations they support.</p>
7523
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7524<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7525<p>This intrinsic does a series of operations atomically. It first loads the
7526 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7527 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]7528
7529<h5>Examples:</h5>
7530<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7531%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7532%ptr = bitcast i8* %mallocP to i32*
7533 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7534%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7535 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7536%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7537 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7538%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7539 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7540%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7541</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7542
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7543</div>
7544
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7545<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7546<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7547 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7548</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7549
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7550<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7551
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7552<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7553<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7554 any integer bit width and for different address spaces. Not all targets
7555 support all bit widths however.</p>
7556
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7557<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7558 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7559 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7560 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7561 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]7562</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7563
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7564<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7565<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7566 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7567
7568<h5>Arguments:</h5>
7569<p>The intrinsic takes two arguments, the first a pointer to an integer value
7570 and the second an integer value. The result is also an integer value. These
7571 integer types can have any bit width, but they must all have the same bit
7572 width. The targets may only lower integer representations they support.</p>
7573
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7574<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7575<p>This intrinsic does a series of operations atomically. It first loads the
7576 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7577 result to <tt>ptr</tt>. It yields the original value stored
7578 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7579
7580<h5>Examples:</h5>
7581<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7582%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7583%ptr = bitcast i8* %mallocP to i32*
7584 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7585%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7586 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7587%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7588 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7589%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7590 <i>; yields {i32}:result3 = 2</i>
7591%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7592</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7593
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7594</div>
7595
7596<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7597<h4>
7598 <a name="int_atomic_load_and">
7599 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7600 </a>
7601 <br>
7602 <a name="int_atomic_load_nand">
7603 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7604 </a>
7605 <br>
7606 <a name="int_atomic_load_or">
7607 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7608 </a>
7609 <br>
7610 <a name="int_atomic_load_xor">
7611 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7612 </a>
7613</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7614
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7615<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7616
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7617<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7618<p>These are overloaded intrinsics. You can
7619 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7620 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7621 bit width and for different address spaces. Not all targets support all bit
7622 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7623
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7624<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7625 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7626 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7627 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7628 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]7629</pre>
7630
7631<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7632 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7633 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7634 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7635 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]7636</pre>
7637
7638<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7639 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7640 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7641 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7642 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]7643</pre>
7644
7645<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7646 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7647 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7648 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7649 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]7650</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7651
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7652<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7653<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7654 the value stored in memory at <tt>ptr</tt>. It yields the original value
7655 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7656
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7657<h5>Arguments:</h5>
7658<p>These intrinsics take two arguments, the first a pointer to an integer value
7659 and the second an integer value. The result is also an integer value. These
7660 integer types can have any bit width, but they must all have the same bit
7661 width. The targets may only lower integer representations they support.</p>
7662
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7663<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7664<p>These intrinsics does a series of operations atomically. They first load the
7665 value stored at <tt>ptr</tt>. They then do the bitwise
7666 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7667 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7668
7669<h5>Examples:</h5>
7670<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7671%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7672%ptr = bitcast i8* %mallocP to i32*
7673 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7674%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7675 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7676%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7677 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7678%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7679 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7680%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7681 <i>; yields {i32}:result3 = FF</i>
7682%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7683</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7684
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7685</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7686
7687<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7688<h4>
7689 <a name="int_atomic_load_max">
7690 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7691 </a>
7692 <br>
7693 <a name="int_atomic_load_min">
7694 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7695 </a>
7696 <br>
7697 <a name="int_atomic_load_umax">
7698 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7699 </a>
7700 <br>
7701 <a name="int_atomic_load_umin">
7702 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7703 </a>
7704</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7705
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7706<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7707
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7708<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7709<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7710 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7711 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7712 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7713
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7714<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7715 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7716 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7717 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7718 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]7719</pre>
7720
7721<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7722 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7723 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7724 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7725 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]7726</pre>
7727
7728<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7729 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7730 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7731 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7732 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]7733</pre>
7734
7735<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7736 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7737 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7738 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7739 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]7740</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7741
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7742<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7743<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7744 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7745 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7746
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7747<h5>Arguments:</h5>
7748<p>These intrinsics take two arguments, the first a pointer to an integer value
7749 and the second an integer value. The result is also an integer value. These
7750 integer types can have any bit width, but they must all have the same bit
7751 width. The targets may only lower integer representations they support.</p>
7752
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7753<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7754<p>These intrinsics does a series of operations atomically. They first load the
7755 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7756 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7757 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7758
7759<h5>Examples:</h5>
7760<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7761%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7762%ptr = bitcast i8* %mallocP to i32*
7763 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7764%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7765 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7766%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7767 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7768%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7769 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7770%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7771 <i>; yields {i32}:result3 = 8</i>
7772%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7773</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7774
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7775</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7776
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7777</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7778
7779<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7780<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7781 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7782</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7783
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7784<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7785
7786<p>This class of intrinsics exists to information about the lifetime of memory
7787 objects and ranges where variables are immutable.</p>
7788
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7789<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7790<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7791 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7792</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7793
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7794<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7795
7796<h5>Syntax:</h5>
7797<pre>
7798 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7799</pre>
7800
7801<h5>Overview:</h5>
7802<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7803 object's lifetime.</p>
7804
7805<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7806<p>The first argument is a constant integer representing the size of the
7807 object, or -1 if it is variable sized. The second argument is a pointer to
7808 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7809
7810<h5>Semantics:</h5>
7811<p>This intrinsic indicates that before this point in the code, the value of the
7812 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]7813 never be used and has an undefined value. A load from the pointer that
7814 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7815 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7816
7817</div>
7818
7819<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7820<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7821 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7822</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7823
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7824<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7825
7826<h5>Syntax:</h5>
7827<pre>
7828 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7829</pre>
7830
7831<h5>Overview:</h5>
7832<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7833 object's lifetime.</p>
7834
7835<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7836<p>The first argument is a constant integer representing the size of the
7837 object, or -1 if it is variable sized. The second argument is a pointer to
7838 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7839
7840<h5>Semantics:</h5>
7841<p>This intrinsic indicates that after this point in the code, the value of the
7842 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7843 never be used and has an undefined value. Any stores into the memory object
7844 following this intrinsic may be removed as dead.
7845
7846</div>
7847
7848<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7849<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7850 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7851</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7852
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7853<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7854
7855<h5>Syntax:</h5>
7856<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]7857 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7858</pre>
7859
7860<h5>Overview:</h5>
7861<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7862 a memory object will not change.</p>
7863
7864<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7865<p>The first argument is a constant integer representing the size of the
7866 object, or -1 if it is variable sized. The second argument is a pointer to
7867 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7868
7869<h5>Semantics:</h5>
7870<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7871 the return value, the referenced memory location is constant and
7872 unchanging.</p>
7873
7874</div>
7875
7876<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7877<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7878 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7879</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7880
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7881<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7882
7883<h5>Syntax:</h5>
7884<pre>
7885 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7886</pre>
7887
7888<h5>Overview:</h5>
7889<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7890 a memory object are mutable.</p>
7891
7892<h5>Arguments:</h5>
7893<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7894 The second argument is a constant integer representing the size of the
7895 object, or -1 if it is variable sized and the third argument is a pointer
7896 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7897
7898<h5>Semantics:</h5>
7899<p>This intrinsic indicates that the memory is mutable again.</p>
7900
7901</div>
7902
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7903</div>
7904
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7905<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7906<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7907 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7908</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7909
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7910<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7911
7912<p>This class of intrinsics is designed to be generic and has no specific
7913 purpose.</p>
7914
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7915<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7916<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7917 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7918</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7919
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7920<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7921
7922<h5>Syntax:</h5>
7923<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7924 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]7925</pre>
7926
7927<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7928<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7929
7930<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7931<p>The first argument is a pointer to a value, the second is a pointer to a
7932 global string, the third is a pointer to a global string which is the source
7933 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7934
7935<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7936<p>This intrinsic allows annotation of local variables with arbitrary strings.
7937 This can be useful for special purpose optimizations that want to look for
7938 these annotations. These have no other defined use, they are ignored by code
7939 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7940
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7941</div>
7942
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7943<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7944<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7945 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7946</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7947
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7948<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7949
7950<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7951<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7952 any integer bit width.</p>
7953
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7954<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7955 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7956 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7957 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7958 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7959 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]7960</pre>
7961
7962<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7963<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7964
7965<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7966<p>The first argument is an integer value (result of some expression), the
7967 second is a pointer to a global string, the third is a pointer to a global
7968 string which is the source file name, and the last argument is the line
7969 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7970
7971<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7972<p>This intrinsic allows annotations to be put on arbitrary expressions with
7973 arbitrary strings. This can be useful for special purpose optimizations that
7974 want to look for these annotations. These have no other defined use, they
7975 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7976
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7977</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7978
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7979<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7980<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7981 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7982</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7983
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7984<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7985
7986<h5>Syntax:</h5>
7987<pre>
7988 declare void @llvm.trap()
7989</pre>
7990
7991<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7992<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7993
7994<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7995<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7996
7997<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7998<p>This intrinsics is lowered to the target dependent trap instruction. If the
7999 target does not have a trap instruction, this intrinsic will be lowered to
8000 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8001
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8002</div>
8003
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8004<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8005<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]8006 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8007</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8008
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8009<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8010
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8011<h5>Syntax:</h5>
8012<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8013 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8014</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8015
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8016<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8017<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8018 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8019 ensure that it is placed on the stack before local variables.</p>
8020
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8021<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8022<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8023 arguments. The first argument is the value loaded from the stack
8024 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8025 that has enough space to hold the value of the guard.</p>
8026
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8027<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8028<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8029 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8030 stack. This is to ensure that if a local variable on the stack is
8031 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8032 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8033 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8034 function.</p>
8035
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8036</div>
8037
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8038<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8039<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8040 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8041</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8042
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8043<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8044
8045<h5>Syntax:</h5>
8046<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8047 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8048 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8049</pre>
8050
8051<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8052<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8053 the optimizers to determine at compile time whether a) an operation (like
8054 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8055 runtime check for overflow isn't necessary. An object in this context means
8056 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8057
8058<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8059<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8060 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8061 is a boolean 0 or 1. This argument determines whether you want the
8062 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]8063 1, variables are not allowed.</p>
8064
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8065<h5>Semantics:</h5>
8066<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8067 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8068 depending on the <tt>type</tt> argument, if the size cannot be determined at
8069 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8070
8071</div>
8072
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8073</div>
8074
8075</div>
8076
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8077<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8078<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8079<address>
8080 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8081 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8082 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8083 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8084
8085 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8086 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8087 Last modified: $Date$
8088</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8089
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8090</body>
8091</html>